| 1. |
C. Kiattisaksri, 竹田祐二, 大上 悟, 荒牧 正俊, 田中 將己, 古君 修, Voids Nucleation Behavior of Single Crystal Iron in Tensile Deformation, 日本金属学会九州支部・日本鉄鋼協会九州支部・軽金属学会九州支部, 2016.06. |
| 2. |
Hiroaki NAKANO, Hiromitsu Yamashita, Nobuyoshi Sogabe, Satoshi Oue, Hisaaki FUKUSHIMA, Synergistic Effect of Gelatin and Sb on Deposition Behavior and Texture of Zn in Electrowinning, Pb-Zn 2015, 2015.06, 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 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.. |
| 3. |
Effect of antimony and chloride ions and on the deposition behavior and crystal texture of zinc from electrowinning solution. |
| 4. |
中野 博昭, 大上 悟, 福島 久哲, 小林繁夫, Evaluation of Harmful Effects of Impurities in Zn Electrowinning Solution Using Cyclic Voltammetry, European Metallurgical Conference 2013 (EMC2013), 2013.06, 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.. |
| 5. |
Effect of Equal Channel Angular Pressing on the Pitting Corrosion Resistance of Aluminum Alloys with/without Anodization. |
