Language：English   Publishing type：Research paper (scientific journal)  

Zn–Ni alloys were electroplated on a Fe plate with a thickness of 40 μm at 500 A·m−2 and 293 K in unagitated zincate solutions. The reaction product of epichlorohydrin and imidazole (IME) was added to the solution as a brightener at concentrations of 0–5 mL dm–3. The corrosion resistance of the obtained Zn–Ni alloy films was investigated from the polarization curve in 3 mass% NaCl solution before and after the corrosion treatment (formation of corrosion products) for 48 hours. Before the corrosion treatment, the corrosion current density of plated films rarely changed, regardless of the addition of IME into the zincate solution, because the reduction reaction of dissolved oxygen rarely changed. However, in films plated from the solution containing IME, the anode reaction was suppressed, and the corrosion potential shifted toward the noble direction. The suppression of the anode reaction with an addition of IME into the plating solution is attributed to the increase in γ-phase in the plated films. After the corrosion treatment, Zn chlo- ride hydroxide of the corrosion product uniformly formed on the surface when increasing the concentra- tion of IME. The reduction reaction of dissolved oxygen was suppressed by increasing the concentration of IME, resulting in a decrease in corrosion current density.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2023-236

Language：English   Publisher：The Iron and Steel Institute of Japan  

<p>The effect of brighteners on the deposition behavior of Zn–Ni alloys and their microstructure was investigated. Zn–Ni alloys were electrodeposited on Cu electrode at 10–5000 A·m⁻², 10⁵ C·m⁻², and 308 K. Although the degree of suppression of hydrogen evolution differed depending on the kind of brightener, the transition current density at which the deposition behavior shifted from normal to anomalous was practically the same in all the solutions containing brighteners. The current efficiency of the alloy deposition significantly decreased with the addition of brighteners, which had a suppression effect on the Zn deposition. Considering that the brighteners suppressed the Ni deposition more than the Zn deposition, the Ni content in the deposited films decreased with the addition of brighteners. When the brightener of a straight-chain polymer comprising a quaternary ammonium cation (PQ) that can suppress the diffusion of ZnO₂²⁻ and Ni ions in a solution was added, the Ni content in the deposited films increased with increasing current density in a high-current-density region. This was attributed to the fact that Zn, which was preferentially deposited over Ni earlier, reached the diffusion limitation of ZnO₂²⁻, and Ni deposition did not reach the diffusion-limited current density. When PQ and a quaternary ammonium salt with a benzene ring were added to the solution, the films obtained at the diffusion-limited current density of ZnO₂²⁻ exhibited smooth surfaces comprising fine crystals. With the addition of brighteners to increase the overpotential for deposition, the <i>γ</i>-phase (the intermetallic compound of Ni₂Zn₁₁) of the deposited films easily formed.</p>

DOI： 10.2355/isijinternational.isijint-2023-103

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CiNii Research

Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>Electrodeposition of Zn–Zr compound composite was performed under pulsed and double pulsed current conditions at 313 K on unagitated pH 2 sulfate solutions containing Zn²⁺, ZrO²⁺ ions and a polyethylene glycol (PEG). At constant current density of 5000 A∙m⁻², the coarse granular deposits containing Zr compound existed partially. Meanwhile, in pulse electrolysis, the coarse deposits were rarely seen and the both areas of deposited films containing Zr compound and its films being exfoliated were observed. On the contrary, in double pulse electrolysis of high current density (5000 A∙m⁻²) and low current density (500 A∙m⁻²), the coarse deposits were not observed and the fine particle deposits containing Zr compound were present. In double pulse electrolysis, since at low current density, the rate of hydrogen evolution decreases and Zn deposits without co-deposition of Zr compound, the continuous hydrogen evolution is suspended in some areas and the area of hydrogen evolution seems to become random. Although Zr compound concentrated at upper area of deposited films regardless of electrolytic method, it codeposited even at inner part with double pulse electrolysis. The corrosion current density in 3 mass% NaCl solution was the smallest for the films produced by double pulse electrolysis, comparing with films obtained by pulse electrolysis and constant current electrolysis. This is attributed to reduction reaction of dissolved oxygen being suppressed.</p>

DOI： 10.2355/tetsutohagane.tetsu-2023-013

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CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn–Zr compound composite was performed under pulsed and double pulsed current conditions at 313 K on unagitated pH 2 sulfate solutions containing Zn2+, ZrO2+ ions and a polyethylene glycol (PEG). At constant current density of 5000 A∙m−2 , the coarse granular deposits containing Zr compound existed partially. Meanwhile, in pulse electrolysis, the coarse deposits were rarely seen and the both areas of deposited films containing Zr compound and its films being exfoliated were observed. On the contrary, in double pulse electrolysis of high current density (5000 A∙m−2) and low current density (500 A∙m−2), the coarse deposits were not observed and the fine particle deposits containing Zr compound were present. In double pulse electrolysis, since at low current density, the rate of hydrogen evolution decreases and Zn deposits without co-deposition of Zr compound, the continuous hydrogen evolution is suspended in some areas and the area of hydrogen evolution seems to become random. Although Zr com- pound concentrated at upper area of deposited films regardless of electrolytic method, it codeposited even at inner part with double pulse electrolysis. The corrosion current density in 3 mass% NaCl solution was the smallest for the films produced by double pulse electrolysis, comparing with films obtained by pulse electrolysis and constant current electrolysis. This is attributed to reduction reaction of dissolved oxygen being suppressed.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2023-013

Language：English   Publishing type：Research paper (scientific journal)  

Zn–Ni alloys were electroplated on an Fe plate with thicknesses of 40 μm at 500 A·m−2 and 293 K in un- agitated zincate solutions. The reaction product of epichlorohydrin and imidazole (IME) was added in the solution as a brightener at the concentration of 0-5 ml/dm−3. The corrosion resistance of the obtained Zn– Ni alloys films was investigated from the polarization curve in 3 mass% NaCl solution before and after the corrosion treatment (formation of corrosion products) in NaCl solution for 48 h. Before the corrosion treatment, the corrosion current density of plated films rarely changed regardless of addition of IME into the zincate solution because the reduction reaction of dissolved oxygen rarely changed. However, in films plated from the solution containing IME, the anode reaction was suppressed and the corrosion potential shifted to noble direction. The suppression of anode reaction with an addition of IME in plating solution is attributed to the increase in γ-phase in plated films. On the other hand, after the corrosion treatment, the morphology of Zn chloride hydroxide of corrosion product was uniformly formed on the surface with increasing the concentration of IME.
The reduction reaction of dissolved oxygen was suppressed with increasing the concentration of IME, resulting in decrease in corrosion current density.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2022-110

Language：English   Publishing type：Research paper (scientific journal)  

The effect of brighteners on the deposition behavior of Zn–Ni alloys ant its microstructure was investigat- ed. Zn–Ni alloys were electrodeposited on Cu electrode at 10–5000 A·m−2, 105 C·m−2, 308 K in unagitated zincate solutions containing various brighteners. Although the degree of suppression of hydrogen evolu- tion was different depending on the kind of brightener, the transition current density at which the depo- sition behavior shifted from normal to anomalous was almost same in solutions containing brighteners. The current efficiency for alloy deposition significantly decreased with an addition of brighteners which had suppression effect on the Zn deposition. Since the brighteners more suppressed the Ni deposition than Zn deposition, the Ni content in deposited films decreased with an addition of brighteners. When the brightener of a straight-chain polymer composed of a quaternary ammonium cation (PQ) which can suppress the diffusion of ZnO22− and Ni ions in solution was added, the Ni content in deposited films in- creased with increasing current density at high current density region. This is attributed to that Zn which is preferentially deposited over Ni earlier reached the diffusion limitation of ZnO22− ions and Ni deposi- tion didn’t reach the diffusion-limited current density. When both PQ and a quaternary ammonium salt with a benzene ring were added in solution, the films obtained at the diffusion-limited current density of ZnO22− ions exhibited the smooth surfaces composed of fine crystals. With an addition of brighteners to increase the overpotential for deposition, the γ-phase (intermetallic compound of Ni2Zn11) of the deposit- ed films was formed easily.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2022-110

Language：Japanese   Publisher：The Japan Institute of Metals and Materials  

DOI： 10.2320/jinstmet.erj202202

CiNii Research

Language：English   Publisher：The Japan Institute of Metals and Materials  

<p>Cu electrorefining using a low-grade copper anode is desirable from the standpoint of electric power savings. Cu electrolysis was carried out in an unagitated sulfate solution with a low-grade copper anode, and the effect of impurity ions and additives in the solution on the passivation of the anode was investigated. The time when anode passivation firstly occurs shortened significantly in a solution containing 0.596 mol·dm⁻³ of Ni²⁺ ions as impurity and shortened somewhat in a solution containing As⁵⁺(0.053 mol·dm⁻³) or Bi³⁺(0.0005 mol·dm⁻³) ions. Sn²⁺(0.0004 mol·dm⁻³) and As³⁺(0.053 mol·dm⁻³) ions slightly decreased the time to passivation, but Sb³⁺(0.004 mol·dm⁻³) ions did not. The viscosity coefficient of the solution increased when the 0.596 mol·dm⁻³ of Ni²⁺ ions were added to the solution, while the diffusion coefficient of Cu²⁺ ions decreased. The compound of the As–Sb–O or As–Bi–O system was formed in anode slime when the As⁵⁺(0.053 mol·dm⁻³) or Bi³⁺(0.0005 mol·dm⁻³) ions were added to the solution, which seemed to increase the compactness of slime. The time to passivation was slightly longer in thiourea-free solution but shortened when the concentration of thiourea was increased from 0.525 to 2.24 mmol·dm⁻³. The time to passivation was constant in solutions containing 0 to 1.13 mmol·dm⁻³ of Cl⁻ ions, but significantly decreased as the concentration of Cl⁻ ions increased above 1.13 mmol·dm⁻³. Cl⁻ ions formed Cu–Cl at the upper area of anode slime, which increased the compactness of slime and promoted the passivation.</p><p> </p><p>This Paper was Originally Published in Japanese in J. Japan Inst. Metals <b>86</b> (2022) 97–106.</p>

DOI： 10.2320/matertrans.mt-m2022087

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CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Cu electrorefining using a low-grade copper anode is desirable from the standpoint of electric power savings. Cu electrolysis was carried out in an unagitated sulfate solution with a low-grade copper anode, and the effect of impurity ions and additives in the solution on the passivation of the anode was investigated. The time when anode passivation firstly occurs shortened significantly in a solution containing 0.596 mol·dm13 of Ni2+ ions as impurity and shortened somewhat in a solution containing As5+(0.053 mol·dm13) or Bi3+(0.0005 mol·dm13) ions. Sn2+(0.0004 mol·dm13) and As3+(0.053 mol·dm13) ions slightly decreased the time to passivation, but Sb3+(0.004 mol·dm13) ions did not. The viscosity coefficient of the solution increased when the 0.596mol·dm13 of Ni2+ ions were added to the solution, while the diffusion coefficient of Cu2+ ions decreased. The compound of the As­Sb­O or As­Bi­O system was formed in anode slime when the As5+(0.053 mol·dm13) or Bi3+(0.0005 mol·dm13) ions were added to the solution, which seemed to increase the compactness of slime. The time to passivation was slightly longer in thiourea-free solution but shortened when the concentration of thiourea was increased from 0.525 to 2.24 mmol·dm13. The time to passivation was constant in solutions containing 0 to 1.13 mmol·dm13 of Cl1 ions, but significantly decreased as the concentration of Cl1 ions increased above 1.13 mmol·dm13. Cl1 ions formed Cu­Cl at the upper area of anode slime, which increased the compactness of slime and promoted the passivation.

DOI： doi:10.2320/matertrans.MT-M2022087

Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>The effect of brighteners on the deposition behavior of Zn–Ni alloys ant its microstructure was investigated. Zn–Ni alloys were electrodeposited on Cu electrode at 10–5000 A·m⁻², 10⁵ C·m⁻², 308 K in unagitated zincate solutions containing various brighteners. Although the degree of suppression of hydrogen evolution was different depending on the kind of brightener, the transition current density at which the deposition behavior shifted from normal to anomalous was almost same in solutions containing brighteners. The current efficiency for alloy deposition significantly decreased with an addition of brighteners which had suppression effect on the Zn deposition. Since the brighteners more suppressed the Ni deposition than Zn deposition, the Ni content in deposited films decreased with an addition of brighteners. When the brightener of a straight-chain polymer composed of a quaternary ammonium cation (PQ) which can suppress the diffusion of ZnO₂²⁻ and Ni ions in solution was added, the Ni content in deposited films increased with increasing current density at high current density region. This is attributed to that Zn which is preferentially deposited over Ni earlier reached the diffusion limitation of ZnO₂²⁻ ions and Ni deposition didn’t reach the diffusion-limited current density. When both PQ and a quaternary ammonium salt with a benzene ring were added in solution, the films obtained at the diffusion-limited current density of ZnO₂²⁻ ions exhibited the smooth surfaces composed of fine crystals. With an addition of brighteners to increase the overpotential for deposition, the γ-phase (intermetallic compound of Ni₂Zn₁₁) of the deposited films was formed easily.</p>

DOI： 10.2355/tetsutohagane.tetsu-2022-104

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CiNii Research

Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>Zn–Ni alloys were electroplated on an Fe plate with thicknesses of 40 μm at 500 A·m⁻² and 293 K in unagitated zincate solutions. The reaction product of epichlorohydrin and imidazole (IME) was added in the solution as a brightener at the concentration of 0-5 ml/dm⁻³. The corrosion resistance of the obtained Zn–Ni alloys films was investigated from the polarization curve in 3 mass% NaCl solution before and after the corrosion treatment (formation of corrosion products) in NaCl solution for 48 h. Before the corrosion treatment, the corrosion current density of plated films rarely changed regardless of addition of IME into the zincate solution because the reduction reaction of dissolved oxygen rarely changed. However, in films plated from the solution containing IME, the anode reaction was suppressed and the corrosion potential shifted to noble direction. The suppression of anode reaction with an addition of IME in plating solution is attributed to the increase in γ-phase in plated films. On the other hand, after the corrosion treatment, the morphology of Zn chloride hydroxide of corrosion product was uniformly formed on the surface with increasing the concentration of IME. The reduction reaction of dissolved oxygen was suppressed with increasing the concentration of IME, resulting in decrease in corrosion current density.</p>

DOI： 10.2355/tetsutohagane.tetsu-2022-110

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CiNii Research

DOI： 10.2320/matertrans.MT-M2022087]

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Language：English   Publisher：The Iron and Steel Institute of Japan  

<p>Zn–Ni alloys were electrodeposited on a Cu electrode at 10–5000 A·m⁻², 5 × 10⁴ C·m⁻², 293 K, 313 K, and 333 K in unagitated zincate solutions containing the reaction product of epichlorohydrin and imidazole (IME) as a brightener. The synergistic effect of IEM and solution temperature on the deposition behavior of Zn–Ni alloys was investigated. The transition current density at which the deposition behavior shifted from normal to anomalous one decreased with IME at 293 K, but did not change regardless of IME addition at 313 K and 333 K. The suppression effect of IME on the Zn and Ni depositions during alloy deposition was observed at 293 K while at 313 K and 333 K, the suppression effect decreased on the Zn deposition but was maintained on the Ni deposition. Therefore, Ni content in deposits significantly decreased with IME as the temperature increased. The current efficiency of Zn deposition significantly decreased with IME at 293 K, with a small degree of decrease at 313 K and 333 K. The C content in deposits was the highest at 293 K and decreased with increasing solution temperature, indicating that the adsorption ability of IME on the cathode decreases with the increasing temperature. As a result, the suppression effect of IME on the Zn deposition decreases with the increasing temperature. The gloss of deposited films was the highest at 293 K, attributed to the IME adsorption ability being large at 293 K and deposited films with fine crystals becoming smooth.</p>

DOI： 10.2355/isijinternational.isijint-2022-160

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CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Zn–Ni alloys were electrodeposited on a Cu electrode at 10–5 000 A·m−2, 5 × 104 C·m−2, 293 K, 313 K, and 333 K in unagitated zincate solutions containing the reaction product of epichlorohydrin and imid- azole (IME) as a brightener. The synergistic effect of IEM and solution temperature on the deposition behavior of Zn–Ni alloys was investigated. The transition current density at which the deposition behavior shifted from normal to anomalous one decreased with IME at 293 K, but did not change regardless of IME addition at 313 K and 333 K. The suppression effect of IME on the Zn and Ni depositions during alloy deposition was observed at 293 K while at 313 K and 333 K, the suppression effect decreased on the Zn deposition but was maintained on the Ni deposition. Therefore, Ni content in deposits significantly decreased with IME as the temperature increased. The current efficiency of Zn deposition significantly decreased with IME at 293 K, with a small degree of decrease at 313 K and 333 K. The C content in deposits was the highest at 293 K and decreased with increasing solution temperature, indicating that the adsorption ability of IME on the cathode decreases with the increasing temperature. As a result, the sup- pression effect of IME on the Zn deposition decreases with the increasing temperature. The gloss of deposited films was the highest at 293 K, attributed to the IME adsorption ability being large at 293 K and deposited films with fine crystals becoming smooth.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2022-160

Language：English   Publisher：The Iron and Steel Institute of Japan  

<p>Zn–Ni alloys were electrodeposited on a Cu electrode at 10–500 A·m⁻² and 5 × 10⁴ C·m⁻² in an unagitated zincate solution at 293, 313, and 333 K. The effect of solution temperature on the electrodeposition behavior of Zn–Ni alloys from alkaline zincate solutions was investigated. The transition current density at which the deposition behavior shifted from a normal to an anomalous co-deposition was almost identical at 293 and 313 K but increased at 333 K, due to enhanced H₂ evolution and Ni deposition at 333 K. The current efficiency for alloy deposition increased with solution temperature in both the normal (10–50 A·m⁻²) and anomalous (500 A·m⁻²) co-deposition regions. In the normal co-deposition region, Ni deposition and H₂ evolution mainly occurred, and the current efficiency increased with solution temperature due to the stronger promotional effect of increase in solution temperature on Ni deposition. In the anomalous co-deposition region at 500 A·m⁻², Zn deposition and H₂ evolution mainly occurred, and Zn deposition appeared to proceed based on a mixed rate-determining process comprising the charge transfer and diffusion of Zn ions. The current efficiency increased with solution temperature due to the acceleration of the Zn ions diffusion. The Ni content in the deposited films increased with the solution temperature at all the current densities, since Ni deposition was accelerated to a greater degree than Zn deposition by increasing the solution temperature in the region where the charge transfer process was rate-limiting. The <i>γ</i>-phase of the deposited films also increased with increasing solution temperature.</p>

DOI： 10.2355/isijinternational.isijint-2022-076

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CiNii Research

Language：Japanese   Publisher：The Japan Institute of Metals and Materials  

<p>The Cu electrorefining using low-grade copper anode is desired from the view point of reduction of electric power. Cu electrolysis was performed using a low-grade copper anode in an unagitated sulfate solution, and the effect of impurity ions and additives in solution on the passivation of anode was investigated. The time when anode passivation firstly occurs shortened significantly in solution containing 0.596 mol·dm⁻³ of Ni²⁺ ions as impurity, and shortened somewhat in solution containing As⁵⁺(0.053 mol·dm⁻³) or Bi³⁺(0.0005 mol·dm⁻³) ions. Sn²⁺(0.0004 mol·dm⁻³) and As³⁺(0.053 mol·dm⁻³) ions slightly decreased the time to passivation, but Sb³⁺ (0.004 mol·dm⁻³) ions rarely decreased the time. When the 0.596 mol·dm⁻³ of Ni²⁺ ions were added in solution, the viscosity coefficient of solution increased and the diffusion coefficient of Cu²⁺ ions decreased. When the As⁵⁺(0.053 mol·dm⁻³) or Bi³⁺(0.0005 mol·dm⁻³) ions were added in solution, the compound of As-Sb-O or As-Bi-O system was formed in anode slime, which seemed to increase the compactness of slime. The time to passivation was slightly longer in thiourea-free solution, but shortened with increasing the concentration of thiourea from 0.525 to 2.24 mmol·dm⁻³. In the solutions containing 0 to 1.13 mmol·dm⁻³ of Cl⁻ ions, the time to passivation was constant, but significantly shortened with increasing the concentration of Cl⁻ ions at the region above 1.13 mmol·dm⁻³. Cl⁻ ions formed CuCl at the upper area of anode slime, as a result, increased the compactness of slime and promoted the passivation.</p>

DOI： 10.2320/jinstmet.j2022001

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CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Zn–Ni alloys were electrodeposited on a Cu electrode at 10–5000 A·m−2, 5 × 104 C·m−2, and 293, 313 and 333 K in unagitated zincate solutions containing the reaction product of epichlorohydrin and imidazole (IME) as a brightener. The synergistic effect of IEM and solution temperature on the deposition behavior of Zn–Ni alloy was investigated. The transition current density, at which the deposition behavior shifted from the normal type to anomalous ones, decreased with IME at 293 K, but didn’t change regardless of IME addition at 313 and 333 K. The suppression effect of IME on the Zn and Ni depositions during alloy deposition was observed at 293 K, while at 313 and 333 K, the suppression effect was decreased on the Zn deposition but was maintained on the Ni deposition. Therefore, Ni content in deposits significantly decreased with IME as temperature increased. The current efficiency for Zn deposition significantly decreased with IME at 293 K, while the degree of decrease was small at 313 and 333 K. The content of C in deposits was highest at 293 K, and decreased with increasing solution temperature, indicating that the adsorption ability of IME on the cathode decreases with increasing temperature. As a result, the sup- pression effect of IME on the Zn deposition seems to decrease with increasing temperature. The gloss of deposited films was highest at 293 K.
This is attributed to adsorption ability of IME being large at 293 K and depos- ited films with fine crystals becoming smooth.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2021-105

Language：Japanese   Publishing type：Research paper (scientific journal)  

Zn電析は古くから鋼板の腐食防止のために使用されてきたが，電析膜の耐食性を更に向上させるためにZn合金電析が行われている1–8)。合金電析の中でもZn-Ni合金は，熱安定性と耐食性に優れており，自動車部品，建築資材など様々な産業分野で適用されている。Zn-Ni合金電析は，通常，硫酸塩浴，塩化物浴から行われるが，小物部品等に対する均一電着性の観点からは，ジンケート浴からの方が望ましい。硫酸塩浴，塩化物浴からのZn-Ni合金電析については，従来より多数の研究が行われており，実用的な電流密度の領域では，電気化学的に卑なZnが貴なNiより優先析出する変則型共析挙動を示すことが知られている9–15)。ジンケート浴からのZn-Ni合金の電析については，電析膜中のNi含有率に及ぼす電流密度16–19)，全金属塩濃度20)，撹拌19)，Ni錯化剤濃度19)，浴組成の影響17,19–21)，合金電析の電流効率に及ぼす電流密度18,20)の影響が報告されているが硫酸塩浴，塩化物浴からの場合に比べて電析機構22)に関する研究例が少ない。
一方，浴温は，電析過電圧，均一電着性，金属塩の溶解度，浴導電率等に影響を及ぼす23)。浴温を高くすると，浴の導電率が増加する。また，イオンの拡散係数および金属塩の溶解度が増大するため金属析出の拡散限界電流密度を高くすることが出来る。浴温を低下させると，電析過電圧が増加することにより電析物の結晶粒が微細化し，また均一電着性が改善される。このように，浴温は電析において極めて重要な因子であるが，ジンケート浴からのZn-Ni合金の電析挙動に及ぼす浴温の影響についてはほとんど報告されていない19)。そこで，本研究では，ジンケート浴からのZn-Ni合金電析挙動に及ぼす浴温の影響をZn，Ni析出および水素発生の部分分極曲線に基づき考察した。

DOI： https://www.jstage.jst.go.jp/article/tetsutohagane/108/2/108_TETSU-2021-092/_article/-char/ja/

Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>Zn–Ni alloys were electrodeposited on a Cu electrode at 10–5000 A·m⁻² and 5 × 10⁴ C·m⁻² in an unagitated zincate solution at 293, 313, and 333 K. The effect of solution temperature on the electrodeposition behavior of Zn–Ni alloys from alkaline zincate solutions was investigated. The transition current density at which the deposition behavior shifted from a normal to anomalous codeposition was almost similar at 293 and 313 K but increased at 333 K. The transition current density increased at 333 K due to the enhanced hydrogen evolution and Ni deposition. The current efficiency for alloy deposition increased with solution temperature in both normal (10–50 A·m⁻²) and anomalous (500 A·m⁻²) codepositions region. In a normal codeposition region, Ni deposition and hydrogen evolution mainly occurred, and the current efficiency increased with solution temperature due to a larger promotion effect of increase in solution temperature on the Ni deposition. In an anomalous codeposition region at 500 A·m⁻², Zn deposition and hydrogen evolution mainly occurred, and Zn seems to proceed under a mixed rate-determining process of the charge transfer and diffusion of Zn ions. The current efficiency increased with solution temperature since the diffusion of Zn ions was accelerated. The Ni content in the deposited films increased with solution temperature at all the current densities, since Ni deposition was more accelerated than Zn deposition with increasing solution temperature in the region where the charge transfer process was rate-limiting. The γ phase of the deposited films increased with increasing solution temperature.</p>

DOI： 10.2355/tetsutohagane.tetsu-2021-092

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CiNii Research

Language：Japanese   Publisher：The Iron and Steel Institute of Japan  

<p>Zn–Ni alloys were electrodeposited on a Cu electrode at 10–5000 A·m⁻², 5 × 10⁴ C·m⁻², and 293, 313 and 333 K in unagitated zincate solutions containing the reaction product of epichlorohydrin and imidazole (IME) as a brightener. The synergistic effect of IEM and solution temperature on the deposition behavior of Zn–Ni alloy was investigated. The transition current density, at which the deposition behavior shifted from the normal type to anomalous ones, decreased with IME at 293 K, but didn’t change regardless of IME addition at 313 and 333 K. The suppression effect of IME on the Zn and Ni depositions during alloy deposition was observed at 293 K, while at 313 and 333 K, the suppression effect was decreased on the Zn deposition but was maintained on the Ni deposition. Therefore, Ni content in deposits significantly decreased with IME as temperature increased. The current efficiency for Zn deposition significantly decreased with IME at 293 K, while the degree of decrease was small at 313 and 333 K. The content of C in deposits was highest at 293 K, and decreased with increasing solution temperature, indicating that the adsorption ability of IME on the cathode decreases with increasing temperature. As a result, the suppression effect of IME on the Zn deposition seems to decrease with increasing temperature. The gloss of deposited films was highest at 293 K. This is attributed to adsorption ability of IME being large at 293 K and deposited films with fine crystals becoming smooth.</p>

DOI： 10.2355/tetsutohagane.tetsu-2021-105

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CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

To investigate the effect of halide ions on the electrodeposition behavior and morphology of copper powder, polarization curves were measured and constant current electrolysis of 300 and 500 A·m−2 was conducted in an electrolytic solution containing 0.079 mol·dm−3 Cu2+ and 0.5 mol·dm−3 free H2SO4 at 293 and 303 K without stirring. Cl− promoted the deposition of copper powder, while Br− and I− suppressed deposition. The current efficiency for copper deposition increased with the addition of Cl− and decreased with the addition of Br−. The addition of Cl− reduced the average particle size of the copper powder and caused the dendrite-shaped branches and trunks to grow thinner and longer, resulting in a lower tap density. In contrast, the addition of Br− caused the average particle size, average crystallite size, and tap density of the copper powder to decrease. With increasing Cl− concentration, the current efficiency for copper deposition increased, that is, copper deposition was promoted. This even occurred in the region in which Cu2+ ion diffusion was the rate-determining process, indicating that the deposition of copper powder was affected by the charge-transfer process. The change in the morphology of the copper powder with the addition of halide ions is attributed to the change in the charge-transfer process. The deposition of copper powder appears to proceed under a mixed rate-determining process involving the diffusion of Cu2+ ions and charge transfer.

This Paper was Originally Published in Japanese in J. Japan Inst. Met. Mater. 85 (2021) 207–212. Captions of all figures and tables are slightly modified.

DOI： https://doi.org/10.2320/matertrans.MT-M2021126

Language：Japanese   Publishing type：Research paper (scientific journal)  

It was investigated whether the spherical electrolytic copper powder could be electrolyzed by adding polyethyleneimine (PEI) in the electrolytic solution. In order to identify the optimum electrolysis conditions for the electrodeposition of spherical copper powder, we investigated the effect of molecular weight of PEI, the amount of PEI added, the current density, and the cathode material on the morphology of electrolytic copper powder. The electrodeposited copper powder was analyzed with a scanning electron microscope, a laser diffraction scattering particle size distribution measuring device, and an X-ray diffractometer. It was found that the spherical copper powder can be obtained by electrolysis at 3000 A·m−2 scraping copper powder every 10 to 60 s in solution containing 0.126 mol·dm−3 Cu2+, 0.5 mol·dm−3 free H2SO4 and 1.0 g·dm−3 PEI with average molecular weight 10000.

DOI： https://doi.org/10.2320/jinstmet.J2021032

Language：English   Publishing type：Research paper (scientific journal)  

A Zn–Ni alloy was electrodeposited on a Cu electrode at a current density of 10–5 000 A·m − 2, a charge of 5 × 104 C·m−2, and temperature of 293 K in an unagitated zincate solution containing the reaction product of epichlorohydrin and imidazole (EI polymer) as a brightener. The effect of the EI polymer on the deposition behavior of the Zn–Ni alloy was investigated. The transition current densities at which the deposition behavior shifted from the normal type to anomalous were 50–100 A·m−2 and 10–20 A·m−2 in the EI polymer-free solution and polymer containing solutions, respectively, indicating that the EI polymer decreased the transition current density. The transition current density corresponded to the current density at which the potential of the total polarization curve significantly shifted from the more noble region than the equilibrium potential of Zn to the less noble region. The decrease in transition current density with EI polymer was attributed to the suppression of hydrogen evolution. In addition, the current efficiency for alloy deposition in the high-current-density region decreased due to the suppression of both Zn and Ni depositions. The Ni content of deposited films decreased with EI polymer, indicating that Ni deposition was more suppressed with the EI polymer addition than Zn deposition. With increasing current density, the crystals of the films deposited from the EI polymer-containing solution smoothened and showed sig- nificant brightness. The oxidation reaction of the films deposited from the EI polymer-containing solution was suppressed, thus causing the corrosion potential to shift to a noble direction.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2021-080

Language：Japanese   Publishing type：Research paper (scientific journal)  

To investigate the effect of polymer additives and chloride ions on the electrodeposition behavior and morphology of copper powder, the polarization curves were measured and constant current electrolysis of 300 A·m−2 and 500 A·m−2 was conducted in an electrolytic solution containing 0.079 mol·dm−3 of Cu2+ and 0.5 mol·dm−3 of free H2SO4 at 293K and 393 K without stirring. Polyethylene glycol (PEG) and polyethyleneimine (PEI) were used as polymer additives. PEG and PEI had a suppressing effect on the electrodeposition of copper powder. The current efficiency for Cu deposition decreased with the addition of PEG and PEI. The addition of PEG decreased the average particle size of the copper powder, while PEI didn’t change the average particle size. When Cl− coexisted with PEG, the suppressing effect on the electrodeposition of copper powder became even greater and the particle size of the copper powder became finer than when Cl− or PEG was added alone

DOI： https://doi.org/10.2320/jinstmet.J2021018

Language：Japanese   Publishing type：Research paper (scientific journal)  

To investigate the effect of halide ions on the electrodeposition behavior and morphology of copper powder, the polarization curves were measured and constant current electrolysis of 300 A·m−2 and 500 A·m−2 was conducted in an electrolytic solution of 0.079 mol·dm−3 of Cu2+ and 0.5 mol·dm−3 of free H2SO4 at 293 K and 303 K without stirring. In the deposition of copper powder, Cl− had a promoting effect on the deposition of copper powder, while Br− and I− had a suppressing effect. The current efficiency for Cu deposition increased with the addition of Cl− and decreased with Br−. The addition of Cl− reduced the average particle size of the copper powder and grown dendrite-shaped branches and trunks, resulting in a lower tap density. On the other hand, when Br− was added, the average particle size and crystallite size of the copper powder became smaller, and the tap density also became smaller. With increasing Cl− concentration in solution, the current efficiency for Cu deposition increased, that is, copper deposition was promoted even in the diffusion rate-determining region of Cu2+ ions, showing that the deposition of copper powder was affected by the charge transfer process for Cu deposition. The change in morphology of Cu powder with halide ions is attributed to change of the charge transfer process. The deposition of Cu powder seems to proceed under a mixed rate-determining process of the diffusion of Cu2+ ions and charge transfer.

DOI： https://doi.org/10.2320/jinstmet.J2021008

Language：English   Publishing type：Research paper (scientific journal)  

Zn was electrodeposited on an Fe electrode at a current density of 50!5000 A·m"2, charge of 4 © 104 C·m"2, and temperature of 313 K in an unagitated zincate solution containing 0.62 mol·dm"3 of ZnO, 4.0 mol·dm"3 of KOH or NaOH, and organic additives. The e!ects of KOH and NaOH on the deposition behavior of Zn in the solution containing the organic additives and on the microstructure of the deposits were investigated. In a solution containing a straight-chain polymer composed of a quaternary ammonium cation (PQ) and a quaternary ammonium salt with a benzene ring (QA), the current e"ciency for Zn deposition in a high-current-density region (1000!5000 A·m"2) to produce glossy #lms was higher with KOH than that with NaOH. At high current densities above 1000 A·m"2, the Zn deposition approached the di!usion limitation of ZnO22" ions. With the addition of PQ and QA, the di!usion of ZnO22" ions was signi#cantly suppressed, and the degree of suppression was smaller with KOH than that with NaOH. The polarization resistance at 200 A·m"2, which was investigated through alternating current impedance, revealed that the adsorption ability of PQ and QA onto the cathode was smaller with KOH than that with NaOH. Since the suppression e!ect of the additives on the Zn deposition was smaller with KOH than that with NaOH, the current e"ciency for Zn deposition in the high-current-density region was larger with KOH. The upper limit of the current density needed to produce glossy #lms was smaller with KOH than that with NaOH, and spongy thin #lms were partially observed on platelet crystals obtained at high current densities in the KOH solution. The C content resulting from the additives in the deposited Zn was smaller with KOH because the adsorption ability of PQ and QA onto the cathode was smaller with KOH than that with NaOH.

DOI： doi:10.2320/matertrans.MT-M2021027

Language：English   Publishing type：Research paper (scientific journal)  

The electrodeposition of Invar Fe–Ni alloy with low thermal expansion was performed at 100–5 000 A·m􏰖􏰗 and 105 C·m􏰖􏰗 in agitated Watt’s solutions containing NiSO4, NiCl2, FeSO4, malonic acid (C3H4O4), saccharin sodium (C7H4NNaO3S), and H3BO3 at 50°C. With increasing concentration of malonic acid, the Ni content in deposits formed at current densities greater than 2 000 A·m 􏰖 􏰗 decreased, whereas the Ni content increased in deposits formed at current densities less than 1 000 A·m 􏰖 􏰗. The current efficiency for alloy deposition decreased with increasing concentration of malonic acid. The deposits were com- posed of granular crystals whose size decreased with increasing concentration of malonic acid. With the addition of saccharin, the Ni content in the deposits decreased substantially, and the current efficiency for alloy deposition increased. With the addition of boric acid, the Ni content in the deposits somewhat decreased, and the current efficiency for alloy deposition increased. The surface morphology of deposits changed as the current density was varied and with the addition of saccharin, whereas it rarely changed with the addition of boric acid. The morphology was found to depend on the Ni content in the deposits. The deposits with a Ni content of 29–38 mass% were composed of granular crystals approximately 300 nm in size, whereas the deposits with a Ni content of 41–52 mass% exhibited a smooth surface that consisted of fine crystals. The effects of additives on the Ni content in deposits and current efficiency can be explained by the changes in the partial polarization curves for Fe and Ni depositions and H2 evolution during Fe–Ni alloy deposition.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2020-105

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Reaction Product of Epichlorohydrin and Imidazole on the Electrodeposition Behavior of Zn-Ni Alloy from Alkaline Zincate Solution

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2020-108

Language：Japanese   Publishing type：Research paper (scientific journal)  

E!ect of Organic Additives on Electrodeposition Behavior of Zn from Zincate Solution Containing Potassium Hydroxide and Its Micro Structure

DOI： doi:10.2320/jinstmet.J2020043

Language：English   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn!Zr and Zn!V oxide composites was performed under galvanostatic conditions at 313 K on unagitated pH 2 sulfate solutions containing Zn2+ and Zr4+ or VO2+ ions and an additive such as polyethylene glycol (PEG). The e!ects of PEG addition on the co- deposition of Zr and V oxides and their polarization behavior, and on the microstructure of the deposits, were investigated. Although the Zr content in the deposits obtained from the Zn!Zr solution in the absence of PEG was approximately zero, it increased signi"cantly at a current density of above 1000A·m"2 following the addition of PEG. In the Zn!V solution, the V content in the deposits obtained from 100 to 2000 A·m"2 was higher with PEG than without it. In the presence of PEG, the cathode potential polarized, the rate of hydrogen evolution increased, and the hydrolysis reaction of Zr4+ and VO2+ ions proceeded smoothly, resulting in an increase in the Zr and V content in the deposits. Additionally, the crystal platelets of Zn in the Zn!Zr and the Zn!V oxide "lms became "ne, and the surface coverage of the spongiform Zr and "lm-like V oxides increased. Furthermore, the corrosion current densities of the Zn!Zr and Zn!V oxide "lms obtained from the solution with PEG were lower than those from the solution without it. The reduction rate of dissolved oxygen decreased in the "lms in the presence of PEG, thereby leading to a decrease in the corrosion current density.

DOI： doi:10.2320/matertrans.MT-M2020164

Language：English   Publishing type：Research paper (scientific journal)  

To elucidate the e!ects of polyethylene glycol (PEG) and glue on the deposition of Zn from electrowinning solution and its resulting crystal structure, Zn electrodeposition was performed at a current density of 600 A·m!2 and a charge of 8.64 © 106 C·m!2 in an agitated sulfate solution containing 1.07 and 1.8 mol·dm!3 of ZnSO4 and H2SO4, respectively, at 45°C. With the additions of PEG and glue, the evolution of hydrogen was suppressed at the current density region less than the critical current density for Zn deposition, decreasing the critical current density of Zn. The degree of decrease in the critical current density of Zn was larger with glue than that with PEG. The current e"ciency for Zn deposition was higher with PEG and glue than that without at the low current density region because the critical current density of Zn decreased with additives. Since the additives suppressed Zn deposition more than the hydrogen evolution at the high current density region, the current e"ciency of Zn decreased by increasing the additive concentration. At the high current density region, little di!erence was observed in the current e"ciency of Zn between PEG and glue. The e!ect of the molecular weight of PEG on the current e"ciency of Zn was rarely observed at the molecular weight above 2000. With the addition of PEG, the deposits became #ne platelets with preferred orientation of f101"1g and layered pyramidally, while f112"0g orientation was obtained, and the platelets grew perpendicularly to the substrate with the addition of glue. The surface roughness of deposited Zn decreased with additives, and it decreased further with PEG compared with that with glue.

DOI： https://doi.org/10.2320/matertrans.MT-M2020182

Language：English   Publishing type：Research paper (scientific journal)  

To elucidate the synergistic effects of gelatin, thiourea, and chloride ions on the deposition behavior, throwing power, and surface roughness of Cu obtained from electrorefining solutions, Cu electrodeposition was performed at a current density of 200 A·m12 and a charge of 5 © 105 C·m12 in an unagitated sulfate solution containing 0.708 and 2.04 mol·dm13 of CuSO4 and H2SO4, respectively, at a temperature of 60°C. Gelatin and chloride ions have synergistic effects on the polarization for Cu deposition, and the polarization effect increased with each concentration. Thiourea was found to promote Cu deposition and decrease the polarization effects of gelatin and chloride ions as its concentration in the solution were increased. The throwing power and surface roughness of the deposited Cu changed depending on the concentration of the three additives. The throwing power of Cu significantly worsened with increasing concentrations of thiourea and its surface roughness decreased with decreasing concentrations of chloride ions. With increasing concentrations of gelatin, the throwing power of Cu improved and its surface roughness decreased. The correlation between the throwing power and polarization resistance of Cu deposition was observed, and the throwing power of Cu improved as its polarization resistance increased. Since the surface roughness of deposited Cu is a result of its micro deposition properties, it does not depend on polarization resistance alone. Thiourea appeared to promote Cu deposition at the concavity, and therefore, it decreased the surface roughness of the deposited copper.

DOI： doi:10.2320/matertrans.M-M2020808

Language：English   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn was performed on an Fe electrode at a current density of 20­5000 A·m12 and a charge of 4 © 104 C·m12 in an unagitated zincate solution at 313 K containing 0.62 mol·dm13 of ZnO, 4.0 mol·dm13 of NaOH, and organic additives. The effects of organic additives on the deposition behavior of Zn and the microstructure of the deposits were investigated. Glossy films were obtained by depositing at current densities higher than 1000A·m12 from the solution containing additives of a straight-chain polymer composed of a quaternary ammonium cation (PQ) and a quaternary ammonium salt with a benzene ring (QA). The polarization curve was separated into partial polarization curves of Zn deposition and hydrogen evolution by using the galvanostatic data of Zn deposition. The overpotentials of the charge transfer of Zn deposition and that of ZnO221 ion diffusion increased with the addition of PQ and QA. The increase in overpotential was considerable at potentials less noble than 11.5 V. Zn deposition reached the diffusion limit of ZnO221 ions at potentials less noble than 11.5 V, indicating that the diffusion of ZnO221 ions was suppressed considerably by PQ and QA. With the addition of PQ and QA, C, N, and H were codeposited with Zn, which demonstrated that the additives of PQ and QA were incorporated into the deposited films. Zn crystallite size decreased with increasing current density. At a high current density of 5000 A·m12, the crystallite size decreased with the addition of PQ and QA, and the surface of the film was smooth. The orientation index of the f101"0g plane of Zn deposited from the solution containing PQ and QA increased with increasing current density. The changes in the crystallite size and crystal orientation of deposited Zn were explained by the deposition overpotential.

DOI： doi:10.2320/matertrans.MT-M2019316

Language：Japanese   Publishing type：Research paper (scientific journal)  

To elucidate the effects of polyethylene glycol(PEG)and glue on the deposition behavior of Zn from electrowinning solutions and its crystal structure, Zn electrodeposition was performed at a current density of 600 A·m−2 and a charge of 8.64 × 106 C·m−2 in an agitated sulfate solution containing 1.07 mol·dm−3 and 1.8 mol·dm−3 of ZnSO4 and H2SO4, respectively, at a temperature of 45°C. With the additions of PEG and glue, the evolution of hydrogen was suppressed at current density region less than the critical current density for Zn deposition, resulting in decrease in critical current density of Zn. The degree of decrease in critical current density of Zn was larger with glue than that with PEG. The current efficiency for Zn deposition was higher with PEG and glue than that without at low current density region because the critical current density of Zn decreased with additives. Since the additives suppressed Zn deposition more than the hydrogen evolution at high current density region, the current efficiency of Zn decreased with increasing concentration of additives in solution. At high current density region, there was little difference in current efficiency of Zn between PEG and glue. The effect of molecular weight of PEG on the current efficiency of Zn was rarely observed at molecular weight above 2000. With an addition of PEG, the deposits became fine platelets crystals with preferred orientation of {1011} and layered pyramidally, while the deposits orientated to {1120} preferentially and the platelets crystals grew perpendicu- larly to the substrate with an addition of glue. The surface roughness of deposited Zn decreased with additives and it was smaller with PEG than that with glue

DOI： doi:10.2320/jinstmet.J2019045

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn-Zr oxide and Zn-V oxide composites was performed under galvanostatic conditions from an unagitated sulfate solution containing Zn2+, Zr4+, or VO2+ ions and an additive such as polyethylene glycol(PEG). The sulfate solution had a pH of 2 and the electrodeposition was performed at 313 K. The effects of PEG on the co-deposition of the Zr oxides and V oxides and their polarization be- havior were investigated. Additionally, the effects of PEG on the microstructure of the deposits were investigated. Although the Zr content in the deposits obtained from the Zn-Zr solution without PEG was approximately zero, it increased significantly at a current density above 1000 A m−2 following the addition of PEG. In the Zn-V solution, the V content in the deposits obtained from 100 A m−2 to 2000 A m−2 was higher with PEG than that without PEG. In the presence of PEG, the cathode potential polarized, the rate of hydrogen evolution increased, and the hydrolysis reaction of Zr4+ and VO2+ ions occurred easily. This resulted in the Zr content and V content increasing in the deposits. Additional- ly, the crystal platelets of Zn in the Zn-Zr oxide film and the Zn-V oxide film became fine, and the surface coverage of the spongiform Zr ox- ide and the film-like V oxide increased. Furthermore, the corrosion current densities of the Zn-Zr oxide film and the Zn-V oxide film ob- tained from the solution with PEG were lower than those from the solution without PEG. The reduction reaction of dissolved oxygen decreased in the films with PEG, thereby decreasing the corrosion current density. [doi:10.2320/jinstmet.J2019031]

DOI： doi:10.2320/jinstmet.J2019031

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn was performed on a Fe electrode at a current density of 20-5000 A·m−2 and a charge of 4 × 104 C·m−2 in an un- agitated zincate solution containing 0.62 mol·dm−3 of ZnO, 4.0 mol·dm−3 of NaOH and organic additives at 313 K. The effects of organic ad- ditives on the deposition behavior of Zn and the microstructure of the deposits were investigated. The films deposited at current densities higher than 1000 A・m−2 from the solution containing additives of a straight-chain polymer composed of quaternary ammonium cation(PQ) and a quaternary ammonium salt with benzene ring(QA)exhibited the gloss. The polarization curve was separated into a partial polarization curve of Zn deposition and that of hydrogen evolution by using the galvanostatic data of Zn deposition. The overpotentials of charge transfer of Zn deposition and that of ZnO22− ions diffusion increased with additions of PQ and QA. The increase in overpotential was remarkable at potential less noble than −1.5 V. Zn deposition reached the diffusion limit of ZnO22− ions at potential less noble than −1.5 V, indicating that the diffusion of ZnO22− ions was greatly suppressed by PQ and QA. With additions of PQ and QA, the C, N and H were co-deposited with Zn, showing that the additives of PQ and QA were incorporated in deposited films. The size of the Zn crystallite decreased with increasing current density. At a high current density of 5000 A・m−2, the crystallite size decreased furthermore with additions of PQ and QA and the filmshowedthesmoothsurface.Theorientationindexofthe{101 ̄0}planeofZndepositedfromthesolutioncontainingPQandQAincreased with current density. The change of the crystallite size and crystal orientation of deposited Zn were explained related to the deposition overpo- tential.

DOI： doi:10.2320/jinstmet.J2019027

Language：Japanese   Publishing type：Research paper (scientific journal)  

To investigate the effect of the surface texture of steel on the crystal orientation relation between Fe and Zn, we deposited Zn at 1500 A・ m−2 and 1.48 × 104 C・m−2 onto both Al-killed and IF steel sheets in an agitated sulfate solution at 313 K. Chemically polishing the steel simplifies the deposition of Zn epitaxially because of the decreased strain in the steel surface. For Zn deposited on Al-killed steel, the Burgers’ orientation relation of {110}Fe//{0001}Zn was completed after the chemical polishing of the steel. In this case, because the orientation of {111}Fe increased and Zn was deposited according to the orientation relation of {110}Fe//{0001}Zn, the orientation of {0001}Zn decreased. In contrast, for Zn deposited on IF steel, the preferred relation was {111}Fe//{0001}Zn. The crystal-grain size of IF steel is larger than that of Al-killed steel, which makes the epitaxial growth of Zn easier on IF steel than on Al-killed steel. The orientation of {111}Fe was more promi- nent in IF steel than in Al-killed steel. Because the proportion of {0001}Zn increases under conditions where the epitaxial growth of Zn occurs easily and the orientation {111}Fe was more prominent in IF steel, this appears to be the cause of the relation of {111}Fe//{0001}Zn. The ori- entation relation between the deposited Zn and steel changes based on the strain, crystal orientation, and grain size of the steel. Therefore, the crystal orientation of the deposited Zn changes as well.

DOI： 10.2320/jinstmet.J2019023

Language：Japanese   Publishing type：Research paper (scientific journal)  

The electrodeposition of invar Fe-Ni alloy with low thermal expansion was performed at 100-5000 A·m–2 and 105 C·m–2 in agitated Watt’s solution containing NiSO4, NiCl2, FeSO4, C3H4O4, C7H4NNaO3S and H3BO3 at 50oC. With increasing the concentration of malonic acid, the Ni content in deposits decreased at higher current density region than 2000 A·m–2, while it increased at lower current density region than 1000 A·m–2. The current efficiency for alloy deposition decreased with increasing the concentration of malonic acid. The deposits were composed of granular crystals whose size decreased with increasing the concentration of malonic acid. With an addition of saccharin, the Ni content in deposits significantly decreased, and the current efficiency for alloy deposition increased. With an addition of boric acid, the Ni content in deposits somewhat decreased, and the current efficiency for alloy deposition increased. The surface morphology of deposits changed with the current density and an addition of saccharin, and rarely changed with an addition of boric acid. It was found that the morphology depended on the Ni content in deposits. The deposits with Ni content of 29-38 mass% were composed of granular crystals approximately 300 nm in size, while the deposits with Ni content of 41-52 mass% showed the smooth surface consisted of fine crystals. The effects of additives on the Ni content in deposits and current efficiency can be explained by the change of partial polarization curve for Fe and Ni deposition and hydrogen evolution in Fe-Ni alloy deposition.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2019-045

Language：English   Publishing type：Research paper (scientific journal)  

To elucidate the effects of the electrolysis conditions on the formation of electrodeposited invar Fe–Ni alloys with low thermal expansion, Fe–Ni electrodeposition was performed at 10–5 000 A·m − 2 and 5 × 105 C·m−2 in an agitated solution containing NiSO4, NiCl2, FeSO4, H3BO3, C7H4NNaO3S, and C3H4O4 at 40°C–60°C. In the low-current-density region, the Ni content in the deposits significantly decreased with increasing current density, reached a minimum, and then increased after reaching the diffusion-limiting current density for Fe deposition. With the increasing concentration of FeSO4 in the solution, the Ni con- tent in the deposits decreased in the lower-current-density region, reached a constant at a moderate cur- rent density, and then began to increase at higher current density. As a result, the current density range in which the Ni content in the deposits reached a minimum and remained constant became wider with increasing FeSO4 concentration. With the decreasing pH of the solution, since the partial polarization curve for H2 evolution and the total polarization curve shifted to a higher-current-density region, the curve of the Ni content in the deposits as a function of the current density shifted toward a higher current density. The change in the composition of the Fe–Ni alloy deposits because of the electrolysis conditions can be explained by the changes in the total polarization curve and the partial polarization curves for Fe and Ni deposition and H2 evolution.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2019-023

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn was performed on a Fe electrode at a current density of 20-5000 A·m−2 and a charge of 4 × 104 C·m−2 in an un- agitated zincate solution containing 0.62 mol·dm−3 of ZnO, 4.0 mol·dm−3 of NaOH and organic additives at 313 K. The effects of organic ad- ditives on the deposition behavior of Zn and the microstructure of the deposits were investigated. The films deposited at current densities higher than 1000 A・m−2 from the solution containing additives of a straight-chain polymer composed of quaternary ammonium cation(PQ) and a quaternary ammonium salt with benzene ring(QA)exhibited the gloss. The polarization curve was separated into a partial polarization curve of Zn deposition and that of hydrogen evolution by using the galvanostatic data of Zn deposition. The overpotentials of charge transfer of Zn deposition and that of ZnO22− ions diffusion increased with additions of PQ and QA. The increase in overpotential was remarkable at potential less noble than −1.5 V. Zn deposition reached the diffusion limit of ZnO22− ions at potential less noble than −1.5 V, indicating that the diffusion of ZnO22− ions was greatly suppressed by PQ and QA. With additions of PQ and QA, the C, N and H were co-deposited with Zn, showing that the additives of PQ and QA were incorporated in deposited films. The size of the Zn crystallite decreased with increasing current density. At a high current density of 5000 A・m−2, the crystallite size decreased furthermore with additions of PQ and QA and the film showed the smooth surface. The orientation index of the {101 ̄0} plane of Zn deposited from the solution containing PQ and QA increased with current density. The change of the crystallite size and crystal orientation of deposited Zn were explained related to the deposition overpo- tential. [doi:10.2320/jinstmet.J2019027]

DOI： https://doi.org/10.2320/jinstmet.J2019027

Language：English   Publishing type：Research paper (scientific journal)  

Synchrotron X-ray laminography was used to examine the time-dependent evolution of the three-dimensional (3D) morphology of micropores in sintered iron during the tensile test. 3D snapshots showed that the networked open pores grow wider than 20 μm along the tensile direction, resulting in the internal necking of the specimen. Subsequently, these pores initiated the cracks perpendicular to the tensile direction by coalescing with the surrounding pre-existing microvoids or with the secondary-generated voids immediately before fracture. Topological analysis of the barycentric positions of these microvoids showed that they form the two-dimensional networks within the ∼20 μm of radius area. These observations strongly indicate that the microvoid coalescence could occur on shear planes formed close to the enlarged open pores or between closed pores by strain accumulation and play an important role in the crack initiation.

DOI： https://doi.org/10.1080/00325899.2019.1585032

Language：English   Publishing type：Research paper (scientific journal)  

Electrodeposition of a Zn­Zr oxide composite was performed under galvanostatic conditions from an unagitated sulfate solution containing
Zn2+ and Zr ions, as well as additives, such as NO3

1 ions and polyethylene glycol (PEG), at pH 2 and 313 K. The effect of these additives on the
codeposition of Zr oxide and its polarization behavior, as well as the microstructure of the deposits, was investigated. The Zr content in the
deposits obtained at varying current densities increased significantly with the addition of 2.0 g·dm13 of NaNO3. Zn­Zr oxide films deposited
from the NaNO3-containing solution showed a massive structure composed of fine crystals without crystalline Zn platelets, although large cracks
were observed between the large crystals. EDX analysis revealed that Zr codeposited on the massive crystals as a fine concave-convex oxide.
The corrosion current density of the Zn­Zr oxide films deposited from the NaNO3-containing solution was almost the same as that of pure Zn
deposits, showing that there is no improvement in corrosion resistance when Zn is codeposited with Zr oxide. Moreover, Zr content in the
deposits obtained from the PEG-containing solution increased significantly along with increasing current density above 1000 A·m12
. With the
addition of 1000 mg·dm13 of PEG, the crystalline Zn platelets disappeared, and the deposits were instead composed of fine mesh-like crystals
with a preferred orientation of the f1010! gZn plane, resulting in a smooth surface. The cathodic current density for the reduction of dissolved
oxygen on the Zn­Zr oxide films deposited from the PEG-containing solution was smaller than that of the pure Zn deposits, and as a result, the
corrosion current density of the Zn­Zr oxide films was smaller than that of the pure Zn deposits. The increase in Zr content in the deposits with
NO3
1 ions and PEG is attributed to the acceleration of the hydrolysis of Zr ions. [doi:10.2320/matertrans.M2018353]

DOI： doi:10.2320/matertrans.M2018353

Language：Japanese   Publishing type：Research paper (scientific journal)  

To elucidate the effects of electrolysis conditions on the formation of electrodeposited invar Fe-Ni alloys with low thermal expansion, Fe-Ni electrodeposition was performed at 10-5000 A·m–2 and 5×105 C·m–2 in agitated solution containing NiSO4, NiCl2, H3BO3, FeSO4, C7H4NNaO3S and C3H4O4 at 40-60°C. Ni content in deposits significantly decreased in the low current density region with increasing current density, reached a minimum, and then increased due to reaching at diffusion limiting current density for Fe deposition as the current density increased further. With increasing the concentration of FeSO4 in solution, Ni content in deposits decreased at lower current density region, reached a constant at lower current density, and then began to increase at higher current density. As a result, the current density range where Ni content in deposits was minimum and constant became wider with higher concentration of FeSO4. With decreasing pH in solution, since the partial polarization curve for H2 evolution and total polarization curve sifted to higher current density region, Ni content in deposits-cur- rent density curve shifted to higher current density region. With stirring the solution, Ni content in deposits reached a minimum as the current density increased, and then began to increase at higher current density than without stirring due to increase in diffusion limiting current densi- ty for Fe deposition. The change of the composition in deposits by electrolysis condition can be explained by the changes of the total polariza- tion curve for Fe-Ni alloy deposition and the partial polarization curves for Fe and Ni depositions and H2 evolution.

DOI： https://doi.org/10.2355/tetsutohagane.TETSU-2018-101

Language：English   Publishing type：Research paper (scientific journal)  

Prior to electrodeposition, steel sheets underwent polishing using emery paper, buff, and then electro-
lytic polishing. Zn deposition was performed galvanostatically at 1 500 A/m2

in an agitated sulfate solution
at 40°C to investigate the effect of the surface textures of steel sheets on the crystal orientation of Zn.
The strain of the steel surface and the decrease in Fe grain size due to this strain were largest with emery

paper polishing, then with buff polishing, then when unpolished, and were smallest after electrolytic pol-
ishing. The preferred orientation of the {0001} Zn basal plane of the hcp structure was largest with elec-
trolytic polishing, and decreased in the following order: unpolished, buff polishing, and then with emery

paper polishing. Thus, the preference of the {0001} orientation of Zn increased with decreasing the strain
of steel sheets and increasing the grain size of Fe. With electrolytic polishing, the strain applied to the
steel sheets was decreased, the grain size of Fe increased, and therefore the epitaxial growth of deposited
Zn occurred easily. The initial Zn deposits appeared to grow epitaxially as indicated by the orientation
relationship of {111}Fe//{0001}Zn because the preferred orientation of the steel substrate used in this
study is {111} Fe. The preferred orientation of {0001} Zn seems to be more common under conditions
where the epitaxial growth of deposited Zn is easy to occur.

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2018-429

Language：English   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn-polyethyleneimine composite was performed at 100­12000 A·m12 and 4.8 © 105 C·m12 in agitated sulfate solutions containing 1.84 mol·dm13 of ZnSO4 and 4 g·dm13 of polyethyleneimine at pH 1.8 and at 313 K: the composite’s deposition behavior and the relevant deposits’ micro-structure were investigated. The films obtained at current densities above 4000 A·m12 from solutions containing polyethyleneimine exhibited gloss, and the gloss was highest for solutions containing polyethyleneimine with the highest molecular weight (70000). The preferred orientation of deposited Zn crystals changed from {0001} to {112"0} and {101"0} in the presence of polyethyleneimine, and the size of the platelet-shaped Zn crystals decreased as the polyethyleneimine molecular weight and current density increased. The deposition of Zn was polarized in the presence of polyethyleneimine, and the degree of polarization increased with the current density and with polyethyleneimine’s molecular weight. The C and N contents in deposited films increased as the polyethyleneimine molecular weight and current density increased, indicating an increase in the tendency of polyethyleneimine to be adsorbed onto the cathode. During deposition, polyethyleneimine buffered somewhat the pH increase in the layer of the electrolyte solution in contact with the cathode. At this time, H+ ions are released from polyethyleneimine because of an increase in pH in the cathode’s vicinity, and consequently, the number of electron lone-pairs in N atoms of polyethyleneimine increased, resulting in an increase in the adsorption ability of polyethyleneimine onto the cathode.

DOI： doi:10.2320/matertrans.M2018243

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition Behavior of Zn-Polyethyleneimine Composite from Sulfate Solution and Its Micro Structure

DOI： doi:10.2320/jinstmet.J2018020

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The texture evolution process and mechanism of surface grains in electroformed Ni after annealing with an initially duplex 〈100⟩ + 〈111〉 fiber texture during uniaxial tensile deformation were investigated by using interrupted in situ electron backscattered diffraction. The results showed that the initially duplex 〈100〉 + 〈111〉 fiber texture evolved into the metastable Cube orientation with a weak Cu orientation during the uniaxial tensile deformation. The volume fractions of 〈100〉 and 〈111〉 fiber texture decreased from 54.0% to 29.3% and 16.6% to 6.6%, respectively. The volume of the Cube orientation remained almost stable at 12%, whereas that of the Cu orientation increased from 1% to 2.9%. A simulation of the final preferred orientation based on the Taylor model was a cubic texture, which qualitatively agreed well with the experimental result. The simulated results indicated that the formed Cube and Cu textures evolved from the initial 〈100〉 and 〈111〉 fiber textures, respectively.

DOI： 10.1016/j.matchar.2018.05.004

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： DOI : http://dx.doi.org/10.2355/tetsutohagane.TETSU-2017-079

Language：English   Publishing type：Research paper (scientific journal)  

To clarify the effect of chloride ions on Zn electrowinning in terms of deposition behavior and crystal texture, the partial polarization curve, current efficiency, and AC impedance for Zn deposition as well as its morphology and crystal orientation were investigated. In solutions containing chloride ions, the partial polarization curve for Zn deposition was evidently depolarized, and the degree of depolarization increased when increasing the concentration of chloride ions from 300 to 6,000 mg/L. The exchange current density i₀ for Zn deposition also increased with increasing chloride ion concentration, which indicates that the chloride ions promote the charge-transfer process during Zn deposition. The polarization resistance for Zn deposition measured by AC impedance decreased with increasing chloride ion concentration. Conversely, the capacity of the electric double layer increased with increasing chloride ion concentration from 300 to 1,200 mg/L; however, from 3,000 to 6,000 mg/L, the capacity decreased and approached that obtained from a chloride ion-free solution. On the other hand, the partial polarization curve for hydrogen evolution was almost unchanged by the presence of chloride ions. As a result, the current efficiency of Zn deposition increased by 5–7% and 1.7% in the initial stage of deposition (up until the thickness of Zn reached approximately 2.1 μm) and at 500 A/m² for 6 hours (482 μm), respectively. With the addition of 300 to 1,200 mg/L of chloride ions, the deposited Zn exhibited a preferred orientation of {0001} plane, and it increased with increasing chloride ion concentration, which is attributed to a decrease in the overpotential for Zn deposition; however, no preferred orientation of a specific plane was shown in the deposits when increasing the concentration of chloride ions above 3,000 mg/L. Some spherical concavities resulting from traces of evolved hydrogen gas were observed on the surface of deposited Zn, and the size of the concavities increased with increasing chloride ion concentration. The size of platelet crystals of the deposited Zn decreased with increasing chloride ion concentration, which indicates that the chloride ions possibly promote the nucleation rate of Zn crystals due to specific adsorption onto the cathode.

DOI： 10.2320/matertrans.M-M2017827

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： doi:10.2320/jinstmet.J2017015

Language：English   Publishing type：Research paper (scientific journal)  

Void nucleation plays an important role for determining local deformation properties of ductile materials. In this study, the void nucleation behavior of single-crystal iron was examined in tensile tests. Two micrometer-size single crystals having a different type of slip extracted from electrodeposited pure iron were used to investigate the fracture mechanics during tensile deformation. Scanning electron microscopy (SEM) and high voltage electron microscopy (HVEM) images verified the existence of only a single slip system in the smaller specimen (cross-sectional area A = 16 µm²) and furthermore, no voids were observed. However, multiple slips and voids were observed in the larger specimen (A = 28 µm²). These findings allowed us to reveal that multiple slips are a necessary criterion for void nucleation in single-crystal iron.

DOI： 10.1016/j.msea.2017.06.084

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The phosphating of Mg alloy was performed in unagitated solutions containing 1 g·dm^-3 of Mg, Ca, Sr, and Ba as alkaline earth metals (M) and 50 g·dm^{-3 of} H₃PO₄ of pH 3 at 40°C for 3 min. The structure and formation behavior of the phosphate films were investigated. The X-ray diffraction patterns of phosphate films broadened irrespective of the type of alkaline earth metal, which was a characteristic of an amorphous structure. XPS analysis revealed that the valence of P in the phosphate films was pentavalent. The pH in the vicinity of the Mg alloy during the phosphating, as measured using an Sb microelectrode, was approximately 10.4, 11.4, 10.7, and 12.0 in the solutions containing Mg, Ca, Sr, and Ba, respectively. This shows that phosphoric acid dissociates to the third stage during the phosphating, and the phosphate films comprising M₃(PO₄)₂ containing an alkaline earth metal are formed. The phosphating was successively performed in two types of solutions containing different alkaline earth metals, and the cross section was analyzed. As a result, it was determined that the new phosphate films were formed at the interface between the Mg alloy substrate and phosphate films, and the previously formed phosphate films were boosted in the films.

DOI： 10.2320/matertrans.M2016463

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2473/journalofmmij.133.165

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This study investigated the effect of dissolved impurities on the lightness, surface morphology, and current efficiency of deposited nickel during electrowinning. Nickel electrodeposition was performed at a current density of 300 A·m^-2 and 7.2 × 10⁵ C·m^-2 of charge in an unagitated chloride solution containing Mn²⁺, Cr³⁺, and SO_{4 2-} ion impurities with a pH from 1 to 3, at a temperature of 333 K. Solutions containing 10 g·dm^-3 of Mn²⁺ resulted in a slight decrease in current efficiency for nickel deposition and smaller crystal sizes in the deposited nickel. The lightness of deposited nickel decreased for Mn²⁺ concentrations exceeding 1 g·dm^-3. When nickel deposition was performed using a soluble nickel anode to prevent the formation of MnO₂ at the anode, greater nickel lightness resulted than with an insoluble anode, suggesting that MnO₂ produced by the insoluble anode caused decreased lightness of nickel. In solutions containing Cr³⁺, the current efficiency of nickel gradually decreased with increasing Cr³⁺ concentrations and significantly decreased at Cr³⁺ concentrations above 0.1 g·dm^-3. The lightness of deposited Ni greatly decreased with increasing concentrations of Cr³⁺ above 0.001 g·dm^-3. Formation of Cr(OH)³ at the cathode layer is presumed to suppress nickel deposition, resulting in some codeposition of NiO and Ni(OH)² along with Ni, which causes the nickel current efficiency and lightness to decrease. Conversely, solutions containing SO₄ ^2- resulted in a moderate decrease in nickel current efficiency at SO₄ ^-2 concentrations above 50 g·dm^-3 and a significant decrease above 100 g·dm^-3. The lightness of deposited nickel increased slightly at SO₄ ^-2 concentrations of 20 g·dm^-3 and strongly increased above 20 g·dm^-3. Because the overpotential for nickel deposition increases with the concentration of SO₄ ², the surface of the deposited nickel becomes smooth, resulting in greater lightness.

DOI： 10.2320/matertrans.M2016442

Language：English   Publishing type：Research paper (scientific journal)  

To elucidate the synergistic effect of gelatin, thiourea and chloride ions on the surface roughness, throwing power and polarization curves for Cu deposition from electrorefining solution, Cu electrodeposition was performed at a current density of 200 A•m^-2 and 5×10⁵ C•m^-2 of charge in an unagitated sulfate solution containing 0.708 mol•dm^-3 of CuSO₄ and 2.04 mol•dm^-3 of H₂SO₄ at a temperature of 60°C. In solutions containing three kinds of additives such as gelatin, thiourea and chloride ions, the surface roughness of deposited Cu decreased with increasing the concentration of thiouea and gelatin and decreasing the chloride ions. On the other hand, the throwing power of deposited Cu was improved with decrease in thiourea and increase in gelatin in solutions containing three kinds of additives. The throwing power of deposited Cu was significantly improved in solution containing both gelatin and chloride ions. The polarization resistance dE/di for Cu deposition increased in solution containing both gelatin and chloride ions, which resulting in improvement of throwing power of Cu deposition. As small amounts of thiourea have a depolarization effect on Cu deposition, a leveling effect is expected owing to the promotion of deposition at recesses.

DOI： 10.2320/jinstmet.J2017015

Language：English   Publishing type：Research paper (scientific journal)  

To elucidate the synergistic effects of gelatin, thiourea, and chloride ions on the surface roughness, throwing power, and polarization curves for Cu deposition from electrorefining solutions, Cu electrodeposition was performed at a current density of 200 A·m⁻² and a charge of 5 × 10⁵ C·m⁻² in an unagitated sulfate solution containing 0.708 mol·dm−³ of CuSO₄ and 2.04 mol·dm−³ of H₂SO₄ at a temperature of 60C. In solutions containing all three additives (gelatin, thiourea, and chloride ions), the surface roughness of deposited Cu decreased with increasing thiourea and gelatin concentrations and decreasing chloride ions concentration. On the other hand, the throwing power of deposited Cu improved with decreasing thiourea concentration and increasing gelatin concentration in solutions containing all three additives. The throwing power of deposited Cu was significantly improved in solutions containing both gelatin and chloride ions. The polarization resistance dE/di for Cu deposition increased in solutions containing both gelatin and chloride ions, resulting in an improvement in the throwing power of Cu deposition. As small amounts of thiourea have a depolarization effect on Cu deposition, a smoothing effect is expected to result from the promotion of deposition at recesses.

DOI： 10.2320/matertrans.M2017215

Language：Japanese   Publishing type：Research paper (scientific journal)  

The phosphate coating for Mg alloy was performed in the unagitated solutions containing 1 g dm 3 of Mg, Ca, Sr and Ba as alkali earth metal and 50 g dm 3 of H3PO4 of pH 3 and 40 C for 3 min, and the structure and formation behavior of the phosphate films were investigated. The X ray diffraction patterns of phosphate films broadened regardless of the kinds of alkali earth metal, which was a characteristic of an amorphous structure. XPS analysis revealed that the valence of P in the phosphate films was pentavalent. The pH in the vicinity of the Mg alloy during the phosphate coating, as measured using an Sb microelectrode, was approximately 10.4, 11.4, 10.7, 12.0 in the solutions containing Mg, Ca, Sr and Ba, respectively, which shows that the phos- phoric acid dissociates to the third stage during the phosphate coating and the phosphate films composed of M3 PO4 2 containing alkali earth metal M are formed. The phosphate coating were successively performed in the two kinds of solutions containing different alkali earth metals and the cross section was analyzed, as a result, it was suggested that the new phosphate films were formed at the interface between Mg alloy substrate and phosphate films and the previously formed phosphate films were boosted up in films.

DOI： doi:10.2320 jinstmet.J2016039

Language：English   Publishing type：Research paper (scientific journal)  

DOI： dos:10.2320/matertrans.H-M2016825

Language：English   Publishing type：Research paper (scientific journal)  

DOI： http://dx.doi.org/10.2355/isijinternational.ISIJINT-2016-111

Language：English   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn–Zr oxide composite from an unagitated sulfate solution containing Zn2+ and Zr ions was investigated at pH 1–2 and at 313 K under galvanostatic conditions. The Zr content was higher in deposits formed from the solution at pH 2 than

DOI： doi:10.2320 matertrans.M2016084

Language：English   Publishing type：Research paper (scientific journal)  

DOI： http://dx.doi.org/10.2355/isijinternational.ISIJINT-2016-110

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Initial Ni Plating on the Structure and Hardness of Electrodeposited Ni-W Alloys with and without Annealing

DOI： http://dx.doi.org/10.2355/tetsutohagane.TETSU-2015-050

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Annealing Duration on the Structure and Hardness of Electrodeposited Ni-W alloys

DOI： http://dx.doi.org/10.2355/tetsutohagane.TETSU-2015-051

Language：English   Publishing type：Research paper (scientific journal)  

The electrodeposition behavior of Zn­Fe alloys has been investigated at 308K at current densities of 10­500A·m12 and a charge of 5 © 104 C·m12 in an unagitated zincate solution containing triethanolamine, which forms a stable complex with Fe2+ ions. The content of Fe in the deposit changed significantly depending on the current density. At current densities lower than 20A·m12, the content of Fe was approximately 90mass%, that is, the Zn­Fe alloy exhibited normal co-deposition, whereby the electrochemically more noble Fe deposited preferentially. At current densities higher than 100A·m12, however, anomalous co-deposition was observed, whereby the less noble Zn deposited preferentially. The current density at which the Fe content in the deposit changed significantly corresponded to that at which the cathode potential in the total polarization curve abruptly shifted to a less noble region than the equilibrium potential for Zn deposition. Iron deposition and H2 evolution were significantly suppressed by the co-existence of Zn2+ ions in the region of anomalous co-deposition at higher current densities, showing the formation of an inhibitor to deposition arising from Zn2+ ions in the cathode layer. The current efficiency for alloy deposition was not close to zero even in the region of normal co-deposition, and the Fe content in the region of anomalous co-deposition was close to the composition reference line, which shows deposition behavior different from that in sulfate solutions. In the region of normal co- deposition at lower current densities, underpotential deposition of Zn occurred with Fe. TEM analysis revealed that Zn­Fe alloys deposited at lower current densities comprised the stable intermetallic compound Fe5Zn21. The activity coefficient of Zn in the deposit appears to remarkably decrease because of this formation of stable Fe5Zn21.

DOI： doi:10.2320/matertrans.M2015230

Language：English   Publishing type：Research paper (scientific journal)  

To investigate the effects of current density and pH of the solution on the lightness and surface morphology of Ni deposit, Ni electrodeposition was performed at a current density of 100 to 500 A·m12 and 7.2 © 105 C·m12 of charge, in an unagitated chloride solution with pH 1 to 3, at 333 K. The composition and structure of the surface of deposits were analyzed by radio frequency glow discharge optical emission spectroscopy and three-dimensional scanning electron microscope (3D-SEM). The lightness of the Ni deposit decreased with increasing pH, and was also related to the current density with the minimum reached at 300A·m12. The concentration of the surface oxygen in the deposits increased with pH, with the highest value obtained at 300 A·m12, which shows that the concentration of surface oxygen possibly affects the lightness. On the other hand, the surface of the Ni deposit was composed of several micrometers of pyramidal microcrystals and the mound formed by the aggregation of pyramidal microcrystals. To separate the two types of structural units, the deposits were cut every 200 nm from the top in the thickness direction using 3D SEM. The number and area of the deposits in the cutting plane were measured and it was found that the lightness of the Ni deposit depended on the surface structure. Therefore, the lightness of the Ni deposit seems to depend on both the surface oxygen content and the microstructure of the deposits.

DOI： doi:10.2320/matertrans.M2014432

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： doi:10.2320/jinstmet.J2014033

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： DOI : http://dx.doi.org/10.2355/tetsutohagane.100.1391

Language：English   Publishing type：Research paper (scientific journal)  

The electrodeposition of a Zn–V oxide composite under galvanostatic conditions from an agitated sul- fate solution without dispersed particles and containing Zn2+ and VO2+ at pH 2 and 313 K was investi- gated. Although the V content in the deposits initially decreased with increasing current density, irrespective of the flow rate of electrolyte, a further increase in the current density resulted in an increase in the V content of the deposits. The curves, which show the relationship between the V content in the deposits and the current density, shifted to the higher-current-density region with increasing flow rate of the electrolyte. Agitation of the electrolyte decreased the V content of the deposits but reduced the seg- regation of V oxide. EDX point analysis of the cross-section of the deposits revealed that the V oxide con- centrated at the surface of the deposits. The polarization curves in 3% NaCl solution revealed that the corrosion potential of the deposited Zn–V oxide films depended on the V content in the deposits, irrespec- tive of the flow rate of electrolyte, and that the corrosion potential shifted toward the more noble direction with the codeposition of V oxide when the V content in the deposits was less than 2 mass%. At V con- tents of <4 mass%, the corrosion current density of the deposits decreased with increasing V content. The corrosion current densities of the deposits obtained from agitated solutions were smaller than those of the deposits obtained from unagitated solutions.

DOI： http://dx.doi.org/10.2355/isijinternational.54.1906

Language：English   Publishing type：Research paper (scientific journal)  

Zn–Ni composite films were electrodeposited under coulostatic (515–5145 C⋅m−2) and galvanostatic (5 A⋅m−2) conditions onto brass plates with a Ni precoating in an unagitated chloride solution at 23°C to investigate the color and structure of the deposited films. The chromaticity of the deposited Zn–Ni com- posite films changed in a clockwise direction in each quadrant of the a*b* diagram of the L*a*b* color space with increasing amount of charge. The deposited films contained S, Zn, and Ni, and their content decreased in the order of S > Zn > Ni. X-ray photoelectron spectroscopy revealed that the deposited films were primarily composed of ZnS, ZnO, and Ni and contained small amounts of Zn(OH)2 and Zn. The color of the deposited films is attributed to interference of light, and the index of refraction of the depos- ited films composed of ZnS, ZnO, and Ni is assumed to be large. When Ni was excluded from the elec- trolytic solution, ZnS did not codeposit and the amount of Zn deposited in the metallic state increased. This result suggests that the Ni deposition induces the codeposition of ZnS.

DOI： DOI: http://dx.doi.org/10.2355/isijinternational.54.1661

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition of Zn-V oxide composite was examined from an agitated sulfate solution without dispersed particles containing Zn2+ and VO2+ at pH 2 and 40 oC under galvanostatic conditions. Although V content in deposits decreased for the moment with increasing current density regardless of flow rate of electrolyte, the further increase in current density brought about the increase in V content in deposits. The curves, which shows the relationship between the V content in deposits and current density, shifted to the higher current density region with increasing flow rate of electrolyte. Agitation of the electrolyte decreased the V content of the deposits but reduced the segregation of V ox- ide. EDX point analysis of cross section of deposits revealed that the V oxide concentrated at the surface of deposits. It was found from the polarization curves in 3% NaCl solution that the corrosion potential of deposited Zn-V oxide films depended on the V content in deposits regardless of the flow rate of electrolyte and it shifted to more noble direction with codeposition of V oxide at V contents in deposits below 2 mass%. At V contents of < 4 mass%, the corrosion current density of deposits decreased with increasing V contents in deposits. The corrosion current densities of deposits obtained from agitated solutions were smaller than that from un-agitated solutions.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Zn electrodeposition was performed galvanostatically on a steel sheet at 1500 A/m2 in an agitated sulfate solution at 40oC to investigate the effect of preadsorption of organic additives on the lightness and morphology of Zn. The organic additives preadsorbed were classified into two types: 1) polyethylene glycol (PEG), gelatin and stearyl dimethyl benzyl ammonium chloride (SDBAC) (type I), which exhibit the po- larization effect on Zn deposition ; 2) saccharin and sodium lauryl sulfate (type II) , which exhibit no polarization effect on Zn deposition. The platelet crystals of deposited Zn became small by preadsorption of all kinds of organic additives. The decrease in size of platelet crystals of Zn with the preadsorption is attributed to both the increase in overpotential for Zn deposition and the decrease in epitaxial growth of Zn. The orientation of {0001} Zn basal plane decreased significantly because of an increase in overpotential for Zn deposition by the preadsorp- tion of PEG and gelatin, and the orientation decreased slightly by saccharin and sodium lauryl sulfate in spite of no polarization effect on Zn deposition. The surface roughness of deposited Zn decreased by the preadsorption of organic additives with the exception of SDBAC. This is due to decrease in size of platelet crystals of Zn. The lightness of deposited Zn was increased by the preadsorption of organic additives with the exception of SDBAC. Because Zn deposited ununiformly by the preadsorption of SDBAC, the surface roughness of Zn increased and the lightness decreased.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Zn-Ni composite electrodeposition was performed under coulostatic (515-5145C·m–2) and galvanostatic (5A·m–2) conditions on a brass with Ni precoating in an unagitated chloride solution at 23oC to investigate the color and structure of the deposited films. The chromaticity of deposited Zn-Ni composite films changed in a clockwise direction in each quadrant of a*b* diagram of La*b* color space with increasing the amount of charge. The deposited films contained S, Zn and Ni, and the content was in the order of S > Zn > Ni. XPS revealed that the deposited films were composed of ZnS, ZnO and Ni mainly and contained Zn(OH)2 and Zn slightly. The color of deposited films is attributed to interference of light, and the index of refraction of deposited films composed of ZnS, ZnO and Ni is assumed to be large. When the Ni was excluded from the electrolytic solution, ZnS did not codeposit and the deposition of Zn in metallic state increased. This suggests that the Ni deposition induces the codeposition of ZnS.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2320/jinstmet.J20130401

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Tensile tests of 16mass%Cr bearing ferritic steels were performed in order to investigate the effect of the mean interparticle spacing (λ) on the local deformation energy. λ of Cr precipitates was changed from 3. 3 to 5. 1 μm. The amounts of Cr precipitates in the specimens tested were controlled to be the same level. The local deformation energy was increased with increasing λ in the specimens without a notch, while the local deformation energy does not depend on λ for the notched specimens. AsB (Angle selective Backscattered Electron Detector) images of voids beneath the fracture surface showed that the difference of the local deformation energy dependence on λ between notchless and notched specimens was due to the void coalescence processes. This finding reveals that the local deformation energy is influenced by the stress triaxiality through the void coalescence behavior.

DOI： http://dx.doi.org/10.2355/tetsutohagane.99.60

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Electrodeposition behavior of Zn­Ni alloys was investigated at current densities of 10­500 A·m12 and a charge of 5 © 104 C·m12 in an unagitated zincate solution containing triethanolamine, which forms a stable complex with Ni2+ ions at 308 K. At low current densities, the Zn­ Ni alloy exhibited normal codeposition, wherein electrochemically more noble Ni deposited preferentially, while at high current densities, it exhibited anomalous codeposition, wherein less noble Zn deposited preferentially. Ni deposition and H2 evolution were significantly suppressed in the region of anomalous codeposition at higher current densities, showing the formation of an inhibitor for deposition, which results from Zn2+ ions in the cathode layer. In contrast, in the region of normal codeposition at lower current densities, the underpotential deposition of Zn apparently occurred with Ni. Because Zn­Ni alloys are composed of a stable intermetallic compound of Ni5Zn21, the activity coefficient of Zn in the deposit appears to decrease remarkably.

DOI： 10.2320/matertrans.M2012241

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Electrodeposition behavior of Zn-Ni alloys was investigated at current densities of 10 to 500 A m- 2 and at amount of charge of 5 × 10 4 Cm -2 in unagitated zincate solution containing triethanolamine to form a stable complex with Ni 2+ ions at 308 K. At low current densities, the deposition of Zn-Ni alloy showed a normal type codeposition, in which electrochemically more noble Ni deposited preferentially, while at high current densities, it showed an anomalous codeposition, in which less noble Zn deposited preferentially. The Ni deposition and H 2 evolution were significantly suppressed in the region of anomalous codeposition at high current densities, showing the formation of inhibitor of deposition resulting from Zn ions in the cathode layer. In the region of nor-mal codeposition at low current densities, the underpotential deposition of Zn apparently occurred with Ni. Because the Zn-Ni alloys are composed of stable intermetallic compound of Ni 5Zn 21, the activity coefficient of Zn in deposit seems to decrease remarkably. © 2012 The Japan Institute of Metals.

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Electrodeposition was performed in an unagitated solution from a urea-based melt bath containing Co and La under galvanostatic (10­ 40 mA·cm12) and coulostatic (10 C·cm12) conditions at 403 K, and the structure of the deposits was investigated. Co deposited in a metallic state at 10 mA·cm12, whereas it was incorporated into deposits mainly as an oxide at high current densities of 30 and 40 mA·cm12. La codeposited with Co as an oxide irrespective of current density. The content of La2O3 increased with current density. The deposits showed a granular crystal structure and became nonuniform crystals comprising large localized granules at high current densities.

DOI： 10.2320/matertrans.M2011379

Language：Japanese   Publishing type：Research paper (scientific journal)  

Synergistic Effect of Addition on Morphology and Texture of Copper Deposited from Electrorefining Solution

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Organic Additives on the Hardness of Ni Electrodeposited from Sulfamate and Watt's Solutions

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Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Current Density and Organic Additives on the Texture and Hardness of Ni Electrodeposited from Sulfamate and Watt's Solutions

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Effect of Preadsorption of Polyethylene Glycol on the Appearance and Morphology of Electrogalvanized Steel Sheets

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Electrodeposition of Sn-Ag Alloys and Evaluation of Connection Reliability for Automotive Connectors

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Effect of Equal Channel Angular Pressing on the Pitting Corrosion Resistance of Aluminum-Copper Alloy

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Language：English   Publishing type：Research paper (other academic)  

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Effect of Thiourea on Copper Electrorefining

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Evaluation of Degradation of Polymer Additive during Long-Term Cu Electrorefining

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Codeposition Behaviour of Impurities in during Electrogalvanization in Sulfate Baths in the Presence of Fe Ions

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Pitting Corrosion Resistance of Aluminum-Magnesium Alloy Processed with Continuous Rotation Evolutional Control

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Effects of Small Amounts of Molybdenum Tungsten or Tin Additive on the Morphology and Orientation of Electrodeposited Zinc

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Pitting Corrosion Resistance of Aluminum-Copper Alloy Processed by Severe Plastic Deformation

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Electrodeposition of Composites of Zinc with Vanadium Oxide from Sulfate Solutions

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Synergistic Effect of Impurities on the Dissolution Behavior of Zn Electrodeposited from Electrowinning Solutions

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Effect of Annealing on the Pitting Corrosion Resistance of Anodized Aluminum-Magnesium Alloy Processed by Severe Plastic Deformation

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of a Small Amount of Mo W and Sn Additives on the Morphology and Orientation of Electrodeposited Zn

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Electrodeposition of Zn-V Oxide Composite from Sulfate Solutions

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Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Polyethylene Glycol on the Dissolution Behavior of Zn Electrodeposited from Impurity-containing Electriwinning Solutions

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Codeposition Behaviour of Impurities in Copper Electrowinning from Cuprous Chloride Solution Hiroaki Nakano Satoshi Oue Yosuke Yamaguchi Kaori Maeda Shinpei Kimura Hisaaki Fukushima and Yoshifumi Abe Journal of MMIJ Vol.123 1(2007)pp.33-38.

Language：Japanese   Publishing type：Research paper (scientific journal)  

TEM-EDX Observations of the Microstructure of Electrodeposited Ni-Sn Alloys Satoshi Oue Hiroaki Nakano Ryo Kuroda Shigeo Kobayashi Hisaaki Fukushima ISIJ Vol.70 10(2006)pp.804-808.

Language：English   Publishing type：Research paper (scientific journal)  

Structure and Polarization Poperties of Zn-Nb Films Formed on Steel Sheet by Sputtering. Hiroshi Kuboyama Hiroaki Nakano Satoshi Oue Hisaaki Fukushima Masataka Masuda Shunichi Hashimoto ISIJ International Vol.46 8(2006)pp.1205-1209.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effect of Polyethylene Glycol on the Morphology of Zn Electrodeposition on Steel Sheet Hiroaki Nakano Satoshi Oue Toshiyuki Miki Shigeo Kobayashi Hisaaki Fukushima Tetsu-to-Hagane Vol.92 8(2006)pp.33-38.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Pitting Corrosion Resistance of Aluminum Alloys Processed by Servere Plastic Deformation after Anodizing In-Joon Son Hiroaki Nakano Satoshi Oue Shigeo Kobayashi Hisaaki Fukushima Zenji Horita The Japan Institute of Metals Vol.70 7(2006)pp.534-540.

Language：English   Publishing type：Research paper (scientific journal)  

TEM-EDX Observations of the Microstructure of Electrodeposited Ni-Sn Alloys Satoshi Oue Hiroaki Nakano Ryo Kuroda Shigeo Kobayashi Hisaaki Fukushima Materials Transactions Vol.47 6(2006)pp.1550-1554.

Language：English   Publishing type：Research paper (scientific journal)  

Pitting Corrosion Resistance of Ultrafine-Grained Aluminum Processed by Servere Plastic Deformation In-Joon Son Hiroaki Nakano Satoshi Oue Shigeo Kobayashi Hisaaki Fukushima Zenji Horita Materials Transactions Vol.47 4(2006)pp.1163-1169.

Language：English   Publishing type：Research paper (scientific journal)  

Effect of Polyethylene Glycol on the Morphology of Zn Electrodeposition on Steel Sheet Hiroaki Nakano Satoshi Oue Toshiyuki Miki Shigeo Kobayashi Hisaaki Fukushima ISIJ International Vol.46 1(2006)pp.106-110.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Structure and Polarization Property of Zn-Nb Films Formed on Steel Sheet by Sputtering Hiroshi Kuboyama Hiroaki Nakano Satoshi Oue Hisaaki Fukushima Masataka Masuda Shunichi Hashimoto TETSU-TO-HAGANE Vol.92 1(2006)pp.16-20.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Pitting Corrosion Resistance of Ultrafine-Grained Aluminum Processed by Servere Plastic Deformation In-Joon Son Hiroaki Nakano Satoshi Oue Shigeo Kobayashi Hisaaki Fukushima Zenji Horita ISIJ Vol.69 10(2005)pp.892-898.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Formation of Poly((2-vinylpyridine) Films on Zn by Galvanostatic Electropolymerization. Hiroaki Nakano Yuki Kuwahara Satoshi Oue Shigeo Kobayashi Hisaaki Fukushima Jeong-Mo Yoon J.Japan Inst.Metals Vol.69 8(2005)pp.780-786.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Mechanism of Anomalous Type Electrodeposition of Fe-Ni Alloys from Sulfate Solutions Hiroaki Nakano Masayuki Matsuno Satoshi Oue Masaaki Yano Shigeo Kobayashi Hisaaki Fukushima J.Japan Inst.Metals. Vol.69 7(2005)pp.548-554.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Quantification og Adhesion Property of Electrodeposited Film - Adhesion of Ni Electrodeposited from Sulfamate Solution

Language：Japanese   Publishing type：Research paper (scientific journal)  

Quantification og Adhesion Property of Electrodeposited Film - Adhesion of Ni Electrodeposited from Sulfamate Solution - Hiroaki Nakano Satoshi Oue Daiki Mishio Yoshinori Nishihata Hisaaki Fukushima Yutaka Tsuru The Surface Finishing Society of Japan Vol.56 7(2005)pp.421-426.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Mg-contained Zn Electroplating from Aqueous Solution Containing Quarternary Ammonium Salt
Hiroaki Nakano Satoshi Oue Shigeo Kobayashi Hisaaki Fukushima Kuniyasu Araga Kazuo Okumura Hiroo Shige
TETSU-TO-HAGANE
Vol.90 10(2004)pp.51-56.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Mechanism of Anomalous Electrodeposition of Fe-Ni

Language：Japanese   Publishing type：Research paper (scientific journal)  

Synergistic Effect of Impurities on the Critical Current Density for Zn Deposition
Hiroaki Nakano Satoshi Oue Tomoko Noguchi Tetsuya Akiyama Hisaaki Fukushima
Shigen-to-Sozai
Vol.120 1(2004)pp.39-42.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Microstructure of Electrodeposited Ni-Sn Alloy.
Satoshi Oue Hiroaki Nakano Hisaaki Fukushima Shigeo Kobayashi Tetsuya Akiyama
Materia Japan
Vol.42 12(2003)pp.909-909.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Effects of Polymer Additives on Copper Electrorefining
Hiroaki Nakano Satoshi Oue Takeshi Ogai Kohei Izumi Tetsuya Akiyama Hisaaki Fukushima
Shigen-To-Sozai
Vol.119 10 11(2003)pp.663-667.

Publishing type：Research paper (scientific journal)  

Vol.54 8(2003)pp.-.

Publishing type：Research paper (scientific journal)  

Vol.54 8(2003)pp.-.

Publishing type：Research paper (scientific journal)  

Vol.53 12(2002)pp.920-925.

Publishing type：Research paper (scientific journal)  

Vol.88 9(2002)pp.513-519.

Publishing type：Research paper (scientific journal)  

Effect of electrolysis factors on crystal orientation and morphology of electrodeposited cobalt
H. Nakano K. Nakahara S. Kawano S. Oue T. Akiyama and H. Fukushima
Journal of Applied Electrochemistry
Vol.32 1(2002)pp.43-48.

DOI： 10.1023/A:1014219106152

Publishing type：Research paper (scientific journal)  

Vol.86 9(2000)pp.584-590.

Publishing type：Research paper (scientific journal)  

Vol.86 2(2000)pp.116-122.

Publishing type：Research paper (scientific journal)  

Vol.86 1(2000)pp.38-44.

Publishing type：Research paper (scientific journal)  

Vol.85 10(1999)pp.728-734.

Publishing type：Research paper (scientific journal)  

Vol.19 (1998)pp.34-39.

Publishing type：Research paper (scientific journal)  

Vol.112 10(1996)pp.729-734.

Language：Japanese   Publishing type：Research paper (scientific journal)  

The electrodeposition of Al-Mn alloys from the molten chlorides salts was carried out to discuss the funda- mental codeposition behavior.
The effect of a current density on the alloy composition and on the cathode current efficiency was investi-
gated. The result shows characteristic feature that the Mn content in the deposits is kept almost constant at relatively lower current densities. At higher current densities, the Mn content in the deposits shifts to reach another constant values which are depended on the bath composition and determined by the limiting current densities of Al and Mn.
Then, the polarization curves were measured for Al and Al-Mn deposition. Both depositions of Al and Mn from the alloy plating baths occur at the same potential and no potential region where Mn or Al deposited individually is observed. The partial polarization curves for Al deposition show that the potential of Al deposition
shifts to less noble direction by 70 mV due to the codeposition with Mn.
Raising temperature promotes the mass transfer of the reactants to increase the limiting current densities
of Al and Mn. On the other hand, the Mn content of the deposits increases at higher temperatures.

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州産業大学   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Zoomによるオンライン開催   Country：Japan  

Event date： 2021.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2021.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2019.9

Language：Japanese  

Venue：京都大学　桂キャンパス   Country：Japan  

Zn2+1.07 mol/L, H2SO41.53 mol/Lとなるように実験室にて作製した浴および同組成の操業浴に添加剤として分子量6000のニカワまたはポリエチレングリコール（PEG）を10 mg/L添加し，浴温45 ℃，攪拌100 rpmにてZnの電解採取を行い，ニカワの代替としてPEGを使用できるかどうかを検討した。実験浴，操業浴からのZn電析の電流効率は共にニカワ，PEGを添加すると5%程度低下した。電流効率はPEGを添加した方がニカワを添加するより1〜2%程高くなった。また，操業浴からの方が，実験浴より1〜2%程電流効率が高くなった。操業浴からの電析Znは，添加剤が無いと水素発生痕による孔が生じたが，ニカワ，PEGを添加すると水素発生痕は消失した。PEGを添加するとZnは{1011}面に優先配向する電場配向繊維型の組織となり，ニカワ添加の場合より結晶粒が微細となり表面粗度がより小さくなった。電析Znの結晶構造に及ぼすニカワの影響は，実験浴と操業浴では若干異なったが，PEG添加の影響は浴の種類に関わらずほぼ同一であった。

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡工業大学   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神奈川大学横浜キャンパス   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神奈川大学横浜キャンパス   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉工業大学   Country：Japan  

銅の電解精製におけるアノードの不動態化は、アノード表面への硫酸銅結晶の析出が主原因であるため、不動態 化を抑制するにはアノード表面からの銅イオンの拡散を促進する必要がある。これまで、電解液組成とアノード 組成の最適化を検討してきたが、今回は電解液の流れに着目し、流れの現状解析と最適化を検討した。現状解析 から、電解に伴って発生する自然対流により、電解槽内の電解液濃度分布が不均一になっていることが分 かった。例えば、銅濃度であれば、電極間の上下で約8g/lの濃度差が生じている。これを電解槽への電解液の給液 および排液方法を変更するという強制対流で緩和可能と推定し、ミニチュアの槽を用いて効果を確認できたた め、その内容を報告する。

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡工業大学   Country：Japan  

Zn2+ 1.07 mol/L, H2SO41.53 mol/Lの溶液に添加剤としてニカワ(分子量6000)またはポリエチレングリコール (PEG，分子量200~35000)を10 mg/L添加し，浴温45°C，攪拌100 rpmにてZnの電解採取を行い，ニカワの 代替としてPEGを使用できるかどうかを検討した。Zn電析の電流効率は，添加剤無添加の場合が最も高く, PEGを 添加した方がニカワを添加するより若干高くなった。Zn析出の部分分極曲線は，PEG，ニカワを添加すると分極 し，その分極の程度は，分子量が同程度であれば，PEGとニカワでほぼ同一であった。PEGについては分子量が低 い方から4000までは分子量の増加に伴い，吸着座が増えることでZn析出に対する分極効果が大きくなるが, 分子 量が4000を超えると，PEG同士の絡まりおよび水溶液への溶解性の低下により，分極効果が低下した。添加剤を 含まない浴では，電析Znの表面には水素発生痕が目立ち, 表面が粗くなった。ニカワまたはPEGを添加すると水素 発生痕はほとんど見られなくなり，表面が平滑になった。ニカワとPEG添加を比較すると，表面粗度はPEG添加の 方が小さくなり，より平滑となった。電析Znの表面粗度，結晶形態に及ぼすPEGの分子量の影響は，特に見られ なかった。

Event date： 2018.9

Language：Japanese  

Venue：福岡工業大学   Country：Japan  

インバー型Fe-Ni合金は，室温付近の熱膨張係数がFe-Ni合金中で最も小さいため，光学機器，電子通信機 器，シャドーマスク等の精密機器材料として，多くの用途に利用されている。電析法によるFe-Ni合金の作製に は，基板の選定が必要不可欠であるが，溶解鋳造等と違い複雑な面や極小部位での形成が可能であり，膜形成速 度が速く，低温作業であるため消費エネルギーが低いといった大量生産に適した特徴を持っている。しかし，水 溶液からのFe-Ni合金電析は，卑なFeの優先析出が変則型共析の挙動を示すため，一定の組成を持つ合金を安定し て得ることが困難である。本研究では，硫酸浴，ワット型ベース浴およびスルファミン酸浴を基本浴として，浴 組成，添加剤，電流密度等の電解条件，電析合金組成，カソード分極，表面形態および電析合金の内部応力に及 ぼす影響について検討した結果を報告する。

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州国際会議場   Country：Japan  

Event date： 2018.6

Language：Japanese  

Venue：北九州国際会議場   Country：Japan  

Event date： 2018.6

Language：Japanese  

Venue：北九州国際会議場   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州国際会議場   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

水溶液中からのZn電析において, Zn皮膜中に Mg, Al, Ti などの標準単極電位が Zn よりも低い活 性金属を Zn 膜中に含有させると耐食性が向上す ることが分かっている。Zr も標準単極電位 E0 が -1.53[V vs.NHE]と, Zn (E0= -0.73[V vs.NHE])より も卑な活性金属であり，Zn 膜中に取り込むことで 耐食性の向上が期待できる。しかし，水溶液中か ら Zr を金属状態で析出させることは困難である ため，本研究では電析時の陰極界面の pH 上昇を 利用して ZrO2+イオンを加水分解させ，そのまま 酸化物として Zn 膜中に取り込むことを検討した。 ポリエチレングリコール(PEG)は，陰極電位を卑 に移行させ，陰極界面の pH を上昇させ ZrO2+イオ ンの加水分解反応を促進させることが期待され る。そこで，本研究では，PEG を添加した溶液に おいて，Zn-ZrO2 の複合電析挙動とその微細構造 を調査した。

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

電気Znめっきは，安価で，犠牲防食により耐食性に優れるため鋼板製品全般にて広く活用されている。通常電気Znめっき鋼板は化成処理を施し，未塗装で用いられることが多い。化成処理後の外観は電析Znの表面形状に左右されるため，その結晶形態を制御することが重要である。電気Znめっきは電気化学プロセスで成膜するため, 電解条件（浴組成, 電流密度等）を変化させることで電析物を容易に制御できる。これは溶融Znめっきと大きく異なる点であり, 特に純Zn電気めっきの場合は電解条件により結晶形態, 配向性が変化し, それに応じて外観, 加工性, 化成処理性が大きく変化する。
電析Znの結晶形態に及ぼす電解条件，電解液への有機系添加剤の影響に関してはこれまでに多数の研究が行われている。しかし，電析Znの結晶形態に及ぼす鋼板の表面性状の影響については，報告　が少なく不明な点が多い。そこで，本研究では表面性状の異なる種々の実用鋼板上にZnを電析させ，電析Znの析出挙動，結晶配向性に及ぼす鋼板の表面性状の影響を調査した。

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：芝浦工業大学   Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州工業大学付属図書館   Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州工業大学付属図書館   Country：Japan  

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢工業大学   Country：Japan  

複合電析は，素材に耐摩耗性，潤滑性，耐食性などの機能を付与することができる。複合電析では，通常，分散材として微粒子を電解液中に懸濁させ，電析の際にその微粒子を皮膜中に取り込む。微粒子は，電解液中で凝集し易いため，電析膜に微細な状態では共析し難く，電解液中で凝集した微粒子が沈降するため製造プロセス上の問題点も多い。そこで本研究では，分散材として，カチオン性の高い水溶性のポリエチレンイミン(以下PEI)を用いて，非懸濁溶液からのZn-PEI複合電析の検討を行った。Zn電析の部分分極曲線，電流効率，電析物の微細構造，耐食性に及ぼすPEI添加の影響について調査した。

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学黒髪南キャンパス   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学黒髪南キャンパス   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学工学部2号館   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学工学部2号館   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学工学部2号館   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉工業大学津田沼キャンパス   Country：Japan  

純度78.7%の粗銅をアノードに用いて，浴温60 ℃，無撹拌にてアノード電流密度200 A/m2でCuの電解精製を行い，陽極の不動態化に及ぼす浴中不純物イオンの影響を調査した。また，回転ディスク電極法により，各種不純物存在下における浴中でのCu2+の拡散係数を測定した。不純物イオンとして，Ni2+, As5+, Bi3+が存在すると不動態化が促進されることが分かった。電解後の陽極上のスライム断面をEPMAにて解析したところ，As5+添加浴では，Sb, As, Oの重なり，Bi3+添加浴では，Bi, As, OまたはBi, S, Oの重なりが見られ，それぞれ，SbAsO4, BiAsO4, Bi2(SO4)3の形成が予想された。スライム中に形成されたSbAsO4, BiAsO4, Bi2(SO4)3が，Cu2+イオンの拡散を阻害し，不動態化を促進すると考えられる。一方，Ni2+添加浴では，浴の粘度が上昇し，浴中でのCu2+の拡散係数が低下することが分かった。また，Ni2+が共存するとCuSO4の溶解度が減少した。Ni2+イオンは，スライムの性状に影響を及ぼすこと無く，不動態化を促進した。

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手大学   Country：Japan  

電析Cuの表面粗度,均一電着性に及ぼすゼラチン,チオ尿素,塩化物イオン添加剤の相乗作用については不明な 点が多い。そこで本研究では,添加剤の濃度を種々変化させて電析Cuの表面粗度,均一電着性に及ぼす添加剤の 相乗効果について調査した。カソードの表面粗度は,添加剤の単独, 複数添加にかかわらずチオ尿素の添加量を増 やすと低下し, 塩化物イオンの添加量を減らすと低下した。ゼラチンは,その濃度を標準条件よりも高くすると粗 度が低下した。標準条件で3種類の添加剤を添加した場合は相乗効果により粗度は低下した。塩化物イオンとゼラ チンが共存すると均一電着性は大きく改善された。また, 3種類の添加剤を添加した場合, チオ尿素の増加は均一電 着性を悪化させるのに対して,ゼラチンの増加は均一電着性を向上させた。標準条件に対して塩化物イオンの濃 度を下げ, かつゼラチンの濃度を上げることでカソードの表面粗度および均一電着性はさらに良くなると考えられ る。

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手大学   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学   Country：Japan  

Event date： 2016.6

Language：English   Presentation type：Oral presentation (general)  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2016.6

Language：Japanese  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2016.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学筑紫キャンパス   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学本郷キャンパス   Country：Japan  

純度78.7%の粗銅をアノードに用いて,浴温60 °C,無撹拌にてアノード電流密度200 A/m2でCuの電解精製を行 い,陽極の不動態化に及ぼす塩化物イオンの影響を調査した。Cl-濃度が0~40 mg/Lの範囲では,約17時間で不 動態化が生じており,Cl-濃度の影響が見られないのに対して,Cl-濃度が100 mg/L以上になると不動態化までの 時間は短くなっており,不動態化に対するCl-イオンの悪影響が認められた。Cl-濃度を400mg/Lと高くすると電解 後のアノード表面に繊維状の組織が見られた。こ

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学西早稲田キャンパス   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：愛媛大学   Country：Japan  

Event date： 2015.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Dusseldolf   Country：Germany  

The partial polarization curves for Zn deposition and the morphology, crystal texture, and crystal orientation of the deposited Zn were investigated to elucidate the synergistic effect of gelatin and antimony on the deposition behavior from electrowinning solutions and on the crystal texture of the deposited Zn. Gelatin suppressed both Zn deposition and hydrogen evolution, whereas antimony promoted both. The current efficiency was a maximum in the solution containing both 10 μg/L of antimony and 1 mg/L of gelatin. Although the current efficiency for Zn deposition significantly decreased at low current densities below 200 A/m2 in the solution containing 50 μg/L of antimony, the addition of gelatin significantly reduced the degree of decrease in the current efficiency owing to the presence of antimony. In the solution containing 50 μg/L of antimony, numerous large holes resulting from the foam mark of hydrogen evolution were observed in the deposited Zn; however, the gelatin decreased the size and number of holes. The crystallite size of deposited Zn reduced with increasing concentration of antimony regardless of the presence of gelatin. The surface of the Zn deposited from solutions containing both gelatin and antimony became a smooth layering of small platelet crystals. In solutions containing both gelatin and antimony, 1 mg/L of gelatin formed a fi- brous type of crystals with a preferred orientation of <11 20> and a nonoriented dispersed type of fine crystals, whereas 10 mg/L of gelatin formed a nonoriented dispersed type of significantly fine crystals from the base of Zn deposition to the top. The crystal textures of Zn deposited from solu- tions containing both gelatin and antimony were obviously different from those deposited from so- lutions containing only gelatin or antimony, which demonstrates the synergistic effect of gelatin and antimony on the crystal texture of Zn.

Event date： 2015.6

Language：Japanese  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2015.6

Language：Japanese  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2015.6

Language：Japanese  

Country：Japan  

Event date： 2015.3

Language：Japanese  

Venue：千葉工業大学   Country：Japan  

Effect of antimony and chloride ions and on the deposition behavior and crystal texture of zinc from electrowinning solution

Event date： 2015.3

Language：Japanese  

Venue：関東学院大学工学部   Country：Japan  

Event date： 2015.3

Language：Japanese  

Venue：関東学院大学工学部   Country：Japan  

Event date： 2015.3

Language：Japanese  

Venue：関東学院大学工学部   Country：Japan  

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州工業大学附属図書館AVホール   Country：Japan  

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州工業大学附属図書館AVホール   Country：Japan  

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州工業大学附属図書館AVホール   Country：Japan  

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2014.6

Language：Japanese  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2014.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2014.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学生産技術研究所   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学野田キャンパス   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京理科大学野田キャンパス   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡工業大学   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：福岡工業大学   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡工業大学   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡工業大学   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡工業大学   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道大学高等教育推進機構   Country：Japan  

Event date： 2013.9

Language：Japanese  

Venue：北海道大学高等教育推進機構   Country：Japan  

Event date： 2013.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Weimar   Country：Germany  

In this study, the harmful effects of impurities in Zn electrowinning solution was evaluated using cyclic voltammetry. The voltammograms obtained from solutions containing Cu, Ni, and Sb as impurities showed a shift in potential for hydrogen evolution to the more noble direction and an increase in critical current density for Zn deposition. When the potential of the working electrode was reverted to the more noble direction after Zn deposition, the deposited Zn was found to dissolve. The potential required for initiating the dissolution of Zn was slightly more noble in solutions containing Cu and Ni than that in impurity-free solutions. In solutions containing Cu and Ni, the further shift in potential to the more noble direction after dissolution of Zn caused an abrupt shift in current density toward the reduction side for hydrogen evolution. This is attributed to the deposition of Cu and Ni with lower hydrogen overpotential on the electrode, which determines if the occurrence of impurity deposition is indicated by the voltammogram. Thus, the harmful effects of impurities on the electrowinning of Zn can be evaluated using cyclic voltammetry.

Event date： 2013.6

Language：Japanese  

Venue：熊本県　パレア   Country：Japan  

Event date： 2013.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本県 パレア   Country：Japan  

Event date： 2012.12

Presentation type：Oral presentation (general)  

Venue：九州工業大学附属図書館AVホール   Country：Japan  

Event date： 2012.9

Presentation type：Oral presentation (general)  

Venue：北海道 室蘭工業大学   Country：Japan  

Event date： 2012.9

Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Event date： 2012.5

Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2012.5

Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：東京都市大学世田谷キャンパス   Country：Japan  

Event date： 2011.10

Presentation type：Oral presentation (general)  

Venue：The Grand Central Hotel, Glasgow   Country：United Kingdom  

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：大阪府立大学   Country：Japan  

Event date： 2011.9

Venue：大阪府立大学   Country：Japan  

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：名古屋大学   Country：Japan  

Event date： 2011.6

Presentation type：Oral presentation (general)  

Venue：Dusseldorf, Germany   Country：Japan  

Event date： 2011.6

Venue：九州大学　筑紫地区　総合研究棟C-Cube   Country：Japan  

Event date： 2011.6

Venue：九州大学　筑紫地区　総合研究棟C-Cube   Country：Japan  

Event date： 2011.5

Venue：福岡国際会議場   Country：Japan  

Event date： 2011.4

Presentation type：Oral presentation (general)  

Venue：九州異大学伊都キャンパス 工学研究院附属 循環型社会システム工学研究センター (CE40) 多目的セミナー室   Country：Japan  

Event date： 2011.3 - 2011.4

Presentation type：Oral presentation (general)  

Venue：東京大学本郷キャンパス   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：関東学院大学金沢八景キャンパス   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.12

Presentation type：Oral presentation (general)  

Venue：九州大学馬出キャンパスコラボステーション2F   Country：Japan  

Event date： 2010.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.11

Presentation type：Oral presentation (general)  

Venue：九州大学伊都キャンパス稲森記念館C会議室   Country：Japan  

Event date： 2010.9

Presentation type：Oral presentation (general)  

Venue：福岡市西区元岡744 九州大学伊都キャンパス   Country：Japan  

Event date： 2010.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.6

Presentation type：Oral presentation (general)  

Venue：Hamburg   Country：Germany  

Event date： 2010.6

Presentation type：Oral presentation (general)  

Venue：Hamburg   Country：Germany  

Event date： 2010.6

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.3 - 2010.4

Presentation type：Oral presentation (general)  

Venue：東京大学生産技術研究所   Country：Japan  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Venue：成蹊大学 (東京都武蔵野市吉祥寺北町3-3-1)   Country：Japan  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2010.2

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2009.11 - 2009.4

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：幕張メッセ 国際会議場   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (invited, special)  

Venue：北海道大学   Country：Japan  

Event date： 2009.9

Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2009.8 - 2010.8

Presentation type：Oral presentation (general)  

Venue：Maritim Hotel Berlin   Country：Germany  

Effect of Equal Channel Angular Pressing on the Pitting Corrosion Resistance of Aluminum Alloys with/without Anodization

Event date： 2009.8

Presentation type：Oral presentation (general)  

Country：Germany  

Event date： 2009.7

Venue：Innsbruck, Austria   Country：Japan  

Event date： 2009.3

Presentation type：Oral presentation (general)  

Venue：千葉工業大学   Country：Japan  

Event date： 2009.3

Presentation type：Oral presentation (general)  

Venue：山梨大学   Country：Japan  

Event date： 2009.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2009.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Country：Germany  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2007.11

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2007.8 - 2008.8

Presentation type：Oral presentation (general)  

Venue：Canada   Country：Canada  

Event date： 2007.8

Presentation type：Oral presentation (general)  

Country：Canada  

Event date： 2007.5

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2007.5

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Chile  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：全北大学   Country：Korea, Republic of  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州工業大学   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Presentation type：Oral presentation (general)  

Country：Germany  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Presentation type：Oral presentation (general)  

Country：Japan  

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：30

Type：Competition, symposium, etc. 

Number of participants：480

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：300