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

DOI： 10.1016/j.engfracmech.2019.106652

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

Vacuum effects on fatigue crack growth in submicrometre-thick freestanding copper films

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

DOI： 10.2472/jsms.67.1050

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

Plastic deformation dominates chemical reactions in Ti/Si multilayered nanofilms

DOI： 10.1016/j.msea.2018.09.031

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

Fracture toughness of freestanding copper films with a thickness of 39 nm

DOI： 10.1016/j.engfracmech.2018.08.019

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

Size effect on tensile creep behavior of micrometer-sized single-crystal gold

DOI： 10.1016/j.mtla.2018.05.004

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

To investigate the thickness effects on fatigue crack propagation properties and mechanisms of as deposited submicrometer-thick freestanding metallic films, fatigue crack propagation experiments in freestanding copper films with a thickness B of approximately 100 nm were conducted at a stress ratio R of 0.1, and compared to the films with B approximate to 500 nm. Electron-beam-evaporated copper films with B approximate to 100 nm had smaller grains compared to the films with B approximate to 500 nm. In addition, fine-grained regions with grain sizes of a few tens of nanometers were observed dispersedly. In films with B approximate to 100 nm, fatigue crack initiated and stably propagated from a notch root by applying a cyclic load. However, the arrest or retardation of fatigue crack propagation often occurred even under constant maximum stress. The fatigue crack propagation rate (da/dN) of films with B approximate to 100 nm is higher than that of films with B approximate to 500 nm, except for the crack arrest cases; films with B approximate to 100 nm showed lower fatigue fracture toughness. Moreover, fatigue crack in films with B approximate to 100 nm propagated even below the fatigue threshold of films with B approximate to 500 nm. Intermittent field emission scanning electron microscope (FESEM) observations of fatigue crack propagation behavior and fracture surface observations as well as microstructural analyses, using electron backscatter diffraction (EBSD), revealed that the fatigue cracks propagated by intergranular cracking and transgranular cracking with intrusion/extrusion formation. Compared to the films with B approximate to 500 nm, the fatigue damage along the crack path became narrower and the frequency of intrusion/extrusion formation decreased. EBSD analysis also revealed that fatigue crack stably propagated in the coarse-grained region, whereas the arrest or retardation of the fatigue crack propagation occurred when the fatigue crack tip reached the fine-grained region, with grain sizes of a few tens of nanometers, indicating that the fine-grained regions have higher resistance to fatigue damage formation than do the coarse-grained regions. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ijfatigue.2017.06.029

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

DOI： 10.2472/jsms.65.869

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

We conducted creep crack propagation experiments on Au freestanding films of 400 nm thickness at room temperature to determine the dominant fracture mechanics parameter. In the experiments, a crack stably propagated accompanied by creep deformation, and it was found that the crack propagation rate was neither uniquely characterized by the stress intensity factor nor the net stress. Furthermore, the steady-state creep J-integral was estimated by an approximate equation using the experimental crack center opening displacement, and the relations were observed within a narrow band irrespective of the specimen width and applied stress. The results indicated that the creep J-integral is the dominant mechanical parameter that characterizes the creep crack propagation rate in Au films.

DOI： 10.1007/s10704-016-0104-z

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

We performed in-situ field emission scanning electron microscopy fracture toughness tests on single-crystalline and polycrystalline submicron-thick Cu films. In all specimens, the notch root became blunt, and a crack was initiated from the blunted notch root. The critical crack tip opening displacement (CTOD) for crack initiation, delta(i), was thickness dependent, where di decreased with a decrease in the thickness. The critical CTOD normalized by the thickness, delta(i)/B, values of the films were similar (delta(i)/B = 1.4-1.9), irrespective of the film thickness and microstructure. This suggested that the local fractures of the submicron Cu films were similar. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.engfracmech.2016.03.031

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

DOI： 10.1016/j.prostr.2016.06.170

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

DOI： 10.1016/j.prostr.2016.06.173

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

The mechanics of fatigue crack initiation in roughly 500-nm-thick freestanding copper (Cu) films were investigated by using single-side-edge-notched specimens and elastic finite element method (FEM) analyses. By applying cyclic loading at a stress ratio R = 0, an intrusion/extrusion was formed near a notch root, and a fatigue crack then initiated at the intrusion/extrusion, which penetrated the film in the thickness direction on a slip plane parallel to a Sigma 3 twin boundary. Local stress distributions were evaluated by three-dimensional FEM analyses, taking account of the individual grain shape and crystal orientation around the fatigue crack initiation sites. The results revealed that a fatigue crack was initiated on slip systems where (i) the slip deformation penetrated the film in the thickness direction without being blocked by grain boundaries or twin boundaries, and (ii) a high resolved shear stress occurred under the conditions in (i). The number of cycles to fatigue crack initiation increased as the intensity of the resolved shear stress field at the fatigue crack initiation site decreased. The resolved shear stress required for fatigue crack initiation in the Cu films is roughly one order of magnitude higher than that in a bicrystal or single-crystal bulk Cu of 30-35 MPa. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ijfatigue.2015.08.019

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

The fatigue crack closure in approximately 500-nm-thick freestanding copper films were investigated by in situ field emission scanning electron microscope (FESEM) observations of the fatigue crack opening/closing behavior at three stress ratios of R=0.1, 0.5, and 0.8 in the low-K-max (maximum stress intensity factor) region of K-max< 4.5 MPam(1/2). The direct observation of fatigue cracks clarified that crack closure occurred at R=0.1 and 0.5, while the fatigue crack was always open at R=0.8. Changes in the gage distance across the fatigue crack during a fatigue cycle were measured from the FESEM images, and the crack opening stress intensity factor Km, was evaluated on the basis of the stress intensity factor K vs. the gage distance relationship. The effective stress intensity factor range Delta K-eff=K-max-K-op was then evaluated. The R-dependence of the da/dN vs. Delta K-eff relationship was smaller than that of the da/dN vs. Delta K relationship. This suggests that Delta K-eff is a dominating parameter rather than AK in the fatigue crack propagation in the films. This paper is the first report on the presence of the fatigue crack closure in submicron-thick freestanding metallic films. (C) 2015 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.msea.2015.07.023

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

We evaluated the thickness effect on fracture toughness in freestanding Cu films with thicknesses of approximately 100, 500, and 2600 nm, on the basis of crack tip opening displacement (CTOD) concept by means of in situ (field emission scanning electron microscopy) FESEM and (transmission electron microscopy) TEM fracture toughness testing. During testing, an acute pre-crack tip blunted gradually and necking deformation in the out-of-plane direction occurred in the region ahead of the crack tip in all the specimens. A crack then initiated from the pre-crack tip and propagated along the necking region resulting in chisel point fracture. Since the small scale yielding condition was not satisfied in the 500 and 2600 nm specimens, the critical CTOD, , at the onset of crack extension was directly evaluated from the in situ images. The results indicate a clear thickness effect on (i.e. decreases as the thickness decreases). Normalized critical CTOD, defined as (where is the thickness), of 100 and 500 nm specimens are similar, . This suggests the presence of a fracture criterion, , in the submicron scale regardless of the film thickness. On the other hand, of the 2600 nm specimen was roughly half of those of the 100 and 500 nm specimens.

DOI： 10.1007/s10704-015-0003-8

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

DOI： 10.1016/j.mspro.2014.06.090

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

DOI： 10.4028/www.scientific.net/AMR.891-892.1681

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

The dominant mechanics and mechanisms of fatigue crack propagation in ca. 500 nm thick free-standing copper films were evaluated at the submicron level using fatigue crack propagation experiments at three stress ratios, R= 0.1, 0.5 and 0.8. Fatigue cracking initiated at the notch root and propagated stably under cyclic loading. The fatigue crack propagation rate (da/dN) vs. stress intensity factor range (Delta K) relation was dependent on the stress ratio R;da/dN, increases with increasing R. Plots of da/dN vs. the maximum stress intensity factor (K-max) exhibited coincident features in the high-K-max region (K-max >= 4.5 MPa m(1/2)) irrespective of R, indicating that K-max is the dominant factor in fatigue crack propagation. In this region, the fatigue crack propagated in tensile fracture mode irrespective of the R value. The region ahead of the fatigue crack tip is plastically stretched by tensile deformation, causing necking deformation in the thickness direction and consequent chisel-point fracture. In contrast, in the low-K-max region (K-max < 4.5 MPa m(1/2)), the da/dN vs. K-max function assumes higher values with decreasing R; in this region, the fracture mechanism depends on R. At the higher R value (R= 0.8), the fatigue crack propagates in the tensile fracture mode similar to that in the high-K-max region. On the other hand, at the lower R values (R= 0.1 and 0.5), a characteristic mechanism of fatigue crack propagation appears: within several grains, intrusions/extrusions form ahead of the crack tip along the Sigma 3 twin boundaries, and the fatigue crack propagates preferentially through the intrusions/extrusions. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.actamat.2013.07.017

Repository Public URL： https://hdl.handle.net/2324/7173481

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

DOI： 10.1299/kikaia.78.808

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

The present study investigated hydrogen embrittlement (HE) cracking upon indentation of high-strength steel. When an indentation test was applied to high-strength steel that included absorbed hydrogen, radial cracks initiated and propagated at the corners of the indentation impression, whereas the as-received steel with no hydrogen absorption exhibited no cracking. In addition, the length of the hydrogen-induced indentation cracks was found to be dependent on the hydrogen content in the steel. A combined experimental and computational investigation was conducted for a mechanistic study of Vickers indentation cracking caused by hydrogen embrittlement. Crack propagation was simulated based on a cohesive zone model in the finite element method and the stress intensity factor for the crack was evaluated. It was found that the simulated crack initiates at loading, and then propagates upon unloading. The value of the stress intensity factor at the indentation crack was in agreement with the threshold resistance to crack propagation for HE cracking (threshold stress intensity factor, K-ISCC). This suggests that the length of the cracks can be used to evaluate the susceptibility of the steel to HE cracking. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.msea.2011.10.049

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

We conducted fracture toughness experiments on freestanding copper films with thicknesses ranging from about 800 to 100 nm deposited by electron beam evaporation to elucidate the size effect on fracture toughness in the nano- or submicron-scale. It was found that initially, the crack propagated stably under loading, and then the crack propagation rate rapidly increased, resulting in unstable fracture. The fracture toughness K(c) was estimated on the basis of the R-curve concept to be 7.81 +/- 1.22 MPa(1/2) for the 800-nm-thick film, 6.63 +/- 1.05 MPa m(1/2) for the 500-nm-thick film and 2.34 +/- 0.54 MPa(1/2) for the 100-nm-thick film. Thus, a clear size effect was observed. The fracture surface suggested that the crack underwent large plastic deformation in the thicker 800-nm and 500-nm films, whereas it propagated with highly localized plastic deformation in the thinner 100-nm film. This size effect in fracture toughness might be related to a transition in deformation and fracture morphology near the crack tip. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.msea.2011.07.071

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

The present study investigates hydrogen embrittlement cracking (HEC) upon Vickers indentation in a high-strength steel. When an indentation test is applied to the high-strength steel, i.e., steel that has absorbed hydrogen, several cracks appear around the impression, whereas as-received steel with no hydrogen absorption does not produce any cracks. An experimental/computational framework is used to elucidate the mechanism of such indentation cracks caused by hydrogen embrittlement. We use the acoustic emission technique (AET) to clarify at which point during the test the crack initiates. In parallel with the experiment, finite element analysis (FEA) is carried out in order to compute the stress field around the impression. Based on the combined results, we discuss the mechanism of crack initiation and the critical stress required to nucleate the crack. The findings of the present paper may be useful for characterizing local contact fracture properties, which are often seriously deteriorated by hydrogen embrittlement. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.mechrescom.2010.01.001

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都工芸繊維大学 （京都市）   Country：Japan  

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：KDDI 維新ホール（山口市）   Country：Japan  

Event date： 2022.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：AP西新宿 (東京都)   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪科学技術センター（大阪市）   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学，オンライン (神戸市)   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学，オンライン (神戸市)   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学，オンライン (神戸市)   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学，オンライン (神戸市)   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学，オンライン (神戸市)   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：南紀白浜マリオットホテル (和歌山県西牟婁郡)   Country：Japan  

Event date： 2019.3

Language：Japanese  

Country：Other  

Event date： 2019.3

Language：Japanese  

Country：Other  

Event date： 2019.3

Language：Japanese  

Country：Other  

Event date： 2019.3

Language：Japanese  

Country：Other  

Event date： 2019.3

Language：Japanese  

researchmap

Event date： 2019.3

Language：Japanese  

researchmap

Event date： 2019.3

Language：Japanese  

researchmap

Event date： 2019.3

Language：Japanese  

researchmap

Event date： 2018.12

Language：Japanese  

Country：Other  

Event date： 2018.12

Language：Japanese  

Country：Other  

Event date： 2018.12

Language：Japanese  

Country：Other  

Event date： 2018.12

Language：Japanese  

Country：Other  

Event date： 2018.12

Language：Japanese  

researchmap

Event date： 2018.12

Language：Japanese  

researchmap

Event date： 2018.12

Language：Japanese  

researchmap

Event date： 2018.12

Language：Japanese  

researchmap

Language：Japanese  

Country：Japan  

高強度鋼のナノ変形特性と水素吸蔵量の関係

Language：Japanese  

Country：Japan  

押込み法による弾塑性特性の評価法

Language：Japanese  

Country：Japan  

Hydrogen Effects on Nano Plastic Deformation in High Strength Steel under Nanoindentation
Nanoindentation was used to study the effect of dissolved hydrogen on the nano plastic deformation in engineering steel. In this study, the results of high strength steel, SCM435 and carbon steel, S15C were discussed. We focused on the hydrogen effect on both onset and the resistance of plastic deformation at nano scale. Nano hardness was found to be increased with increasing in hydrogen content in SCM435 steel. The displacement burst of indentation curve was observed in both materials. The result of SCM435 steel, however, exhibited large scatter due to the large surface roughness. We, thus, investigated the displacement burst which occurred in the same grain of S15C steel. The result revealed that hydrogen increased the indentation force which induced displacement burst. Contrary to this, this force value decreased with a decrease in hydrogen content.

Language：Japanese  

Country：Japan  

ナノ塑性特性に及ぼす吸蔵水素の影響

Language：Japanese  

Country：Japan  

On hydrogen embrittlement cracking in high strength steel subjected to local contact loading

Language：Japanese  

Country：Japan  

押込み法による水素ぜい化き裂発生強度特性の評価

Language：Japanese  

Country：Japan  

自立Cuナノ薄膜の破壊じん性の膜厚依存性

Language：Japanese  

Country：Japan  

自立Cuナノ薄膜における疲労き裂進展特性

Language：Japanese  

Country：Japan  

自立金属ナノ薄膜のき裂進展におけるサイズ効果
We conducted crack propagation experiments on freestanding copper films with thicknesses ranging from about 800 to 100nm deposited by electron beam evaporation to clarify the size effect on fracture toughness in the nano-scale. It was found that initially, the crack propagated stably under loading, and then the crack propagation rate rapidly increased, resulting in unstable fracture. The fracture toughness K_C was estimated on the basis of the R-curve concept, showing a clear size effect where thinner films have smaller fracture toughness. The fracture surface suggested that the crack underwent large plastic deformation in the thicker 800-nm and 500-nm films, whereas it propagated with highly localized plastic deformation in the thinner 100-nm film. This size effect in fracture toughness will be related to a transition in deformation and fracture morphology near the crack tip.

Language：English  

Country：Japan  

OS18-2-1 Indentation Method to Characterize Degradation of High-strength Steel in Hydrogen Environment

Language：English  

Country：Japan  

OS12-4-2 Fatigue crack propagation in freestanding copper nano-films

Language：Japanese  

Country：Japan  

自立Cuナノ薄膜の疲労き裂進展に及ぼす応力比の影響

Language：Japanese  

Country：Japan  

自立Cuナノ薄膜の疲労き裂進展の下限界特性

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展特性の膜厚依存と進展機構の解明

Language：Japanese  

Country：Japan  

ナノ観察と結晶方位解析による自立銅ナノ薄膜の疲労発生機構の解明

Language：Japanese  

Country：Japan  

デジタル画像相関法によるナノ薄膜の高ひずみ塑性特性評価法の開発

Language：Japanese  

Country：Japan  

ナノ観察とEBSD援用応力解析による自立銅ナノ薄膜の疲労損傷発生機構の解明

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜のき裂進展機構と膜厚依存

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展過程のその場FESEM観察

Language：Japanese  

Country：Japan  

自立ナノ薄膜の疲労損傷形成過程のナノ観察

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の破壊じん性試験のその場FESEM観察

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展特性に及ぼすき裂閉口の影響

Language：Japanese  

Country：Japan  

結晶方位解析による自立銅ナノ薄膜の疲労き裂発生強度の力学的評価

Language：Japanese  

Country：Japan  

銅ナノ薄膜の疲労き裂開閉口挙動のその場観察

Language：Japanese  

Country：Japan  

金属単結晶自立ナノ薄膜の破壊じん性

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜における疲労き裂発生の力学条件

Language：Japanese  

Country：Japan  

銅単結晶自立ナノ薄膜の破壊じん性に及ぼす膜厚効果

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展の膜厚依存性

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展下限界近傍におけるき裂開閉口挙動

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展におけるき裂開閉口挙動

Language：Japanese  

Country：Japan  

自立金ナノ薄膜のクリープき裂伝ぱ特性

Language：Japanese  

Country：Japan  

基板形状援用斜め蒸着法による寸法制御ナノコラムの作製と強度実験法の開発

Language：Japanese  

Country：Japan  

ナノ形状・局所応力場制御によるチタンナノコラムの破壊特性評価

Language：Japanese  

Country：Japan  

その場FESEM観察による銅単結晶ナノ薄膜の破壊じん性に及ぼす膜厚効果の解明

Language：Japanese  

Country：Japan  

FESEM局所変形場評価によるナノ薄膜の高ひずみ塑性特性評価法の開発

Language：Japanese  

Country：Japan  

真空環境下におけるナノコラム構造体のクリープ特性

Language：Japanese  

Country：Japan  

単結晶銅ナノ薄膜の疲労き裂進展

Language：Japanese  

Country：Japan  

単結晶・多結晶銅ナノ薄膜の限界CTODに及ぼす膜厚効果

Language：Japanese  

Country：Japan  

自立単結晶銅ナノ薄膜の疲労き裂進展の膜厚依存性

Language：Japanese  

Country：Japan  

ナノコラム構造体の室温下時間依存型変形に及ぼす真空環境効果

Language：English  

Country：Japan  

OS12-8 Effects of Crack Closure on Fatigue Crack Propagation Properties in Submicron-Thick Freestanding Copper Films(Mechanical properties of nano- and micro-materials-2,OS12 Mechanical properties of nano- and micro-materials,MICRO AND NANO MECHANICS)

Language：English  

Country：Japan  

OS12-6 Thickness Effects on Fracture Toughness of Single-crystalline and Polycrystalline Copper Submicron Films(Mechanical properties of nano- and micro-materials-2,OS12 Mechanical properties of nano- and micro-materials,MICRO AND NANO MECHANICS)

Language：Japanese  

Country：Japan  

金薄膜のクリープき裂進展特性

Language：Japanese  

Country：Japan  

自立銅単結晶ナノ薄膜の疲労き裂進展機構

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展特性に及ぼす環境効果

Language：Japanese  

Country：Japan  

ナノコラム構造体の変形と強度に及ぼす環境効果

Language：Japanese  

Country：Japan  

自立銅ナノ薄膜の疲労き裂進展に及ぼす真空環境効果

Language：Japanese  

Country：Japan  

自立単結晶銅ナノ薄膜の疲労き裂進展に及ぼす膜厚効果

Language：Japanese  

Country：Japan  

斜め蒸着法により作製した銅ナノポーラス薄膜の引張およびクリープ特性

Language：Japanese  

Country：Japan  

チタンナノコラムのクリープ特性に及ぼす真空環境効果

Language：Japanese  

Country：Japan  

銅ナノ薄膜の疲労き裂進展の下限界特性に及ぼす真空環境効果

Language：Japanese  

Country：Japan  

円孔基板支持自立薄膜試験片を用いた10nmオーダ厚の銅薄膜の破壊じん性評価

Language：Japanese  

Country：Japan  

銅単結晶ナノ薄膜における疲労き裂発生

Language：Japanese  

Country：Japan  

銅ナノ薄膜の疲労き裂進展特性に及ぼす表面酸化層の影響

Language：Japanese  

Country：Japan  

金単結晶サブミクロン構造体の引張クリープ特性評価

Language：Japanese  

Country：Japan  

金サブミクロン薄膜のクリープき裂進展機構のその場観察

Language：Japanese  

Country：Japan  

チタン/シリコン多層ナノ薄膜の応力誘起化学反応

Language：Others  

Country：Japan  

Effects of vacuum on fatigue crack propagation in freestanding copper submicron films
© 2017 ICF 2017 - 14th International Conference on Fracture. All rights reserved. Fatigue crack propagation properties of approximately 500-nm-thick freestanding copper films were investigated in air and vacuum environments. Fatigue crack propagation rate (da/dN) against stress intensity factor range (K) was decelerated in vacuum compared with da/dN in air in the middle-K region (K ≈ 1.7-3.1 MPam1/2). In contrast, da/dN in vacuum became higher than that in air as K decreased in the low-K region (K ≲ 1.7 MPam1/2). Fracture surface morphologies in the middle- and low-K regions changed by the environment, suggesting that fatigue damage formation process was influenced by the environment.

Language：Others  

Country：Japan  

Effects of film thickness on creep crack propagation mechanisms of gold submicron films
© 2017 Chinese Society of Theoretical and Applied Mechanics. All Rights Reserved. To clarify the creep crack propagation mechanisms of Au submicron films, creep crack propagation experiments were conducted for freestanding film specimens in a thickness range of approximately 100 to 400 nm under in situ FESEM observation. In a 360-nm-thick specimen, the notch root largely blunted and then a crack was initiated at the blunted notch root. A few voids nucleated ahead of the crack tip and the main crack propagated by coalescence of the crack and the voids. In the early stage where creep crack propagation rate was low, creep damage around the crack tip was confined to a small region. In the next stage, creep damage spread over a larger distance, resulting in the slower creep crack propagation rate. The effects of film thickness on the creep crack propagation mechanisms are discussed on the basis of the observed results.

Language：Japanese  

Country：Japan  

銅単結晶サブミクロン薄膜における疲労き裂発生のその場観察

Language：Japanese  

Country：Japan  

金サブミクロン薄膜のクリープき裂進展特性に及ぼす膜厚効果

Language：Japanese  

Country：Japan  

サブミクロン金単結晶の引張クリープ特性

Language：Japanese  

Country：Japan  

10nmオーダ厚銅薄膜の破壊じん性評価

Language：Japanese  

Country：Japan  

サブミクロン銅薄膜の疲労き裂進展の下限界特性に及ぼす酸化の影響

Language：Japanese  

Country：Japan  

サブミクロン銅薄膜の破壊じん性に及ぼす表面酸化層の影響

Language：Japanese  

Country：Japan  

サブミクロン金薄膜のクリープき裂進展のその場FESEM観察

Language：Japanese  

Country：Japan  

サブミクロン銅薄膜の疲労き裂進展に及ぼす表面酸化層の影響

Language：Japanese  

Country：Japan  

サブミクロン銅薄膜の破壊じん性に及ぼす酸化の影響

Language：Japanese  

Country：Japan  

Ti/Si多層ナノ薄膜の応力誘起化学反応開始の力学条件

Language：Japanese  

Country：Japan  

Language：Japanese  

Country：Japan  

斜め蒸着法によるナノポーラス薄膜の作製とそのクリープ特性

Language：Japanese  

Country：Japan  

基板形状援用斜め蒸着法により作製したサブミクロンSiコラムのクリープ特性

Language：Japanese  

Country：Japan  

サブミクロン銅薄膜の疲労き裂進展特性に及ぼす新生面酸化/表面酸化層の影響

Language：Japanese  

Country：Japan  

サブミクロン金属薄膜のクリープき裂進展のその場FESEM観察

Language：Japanese  

Country：Japan  

Ti/Si多層ナノ薄膜における応力誘起化学反応条件の検討

Language：Japanese  

Country：Japan  

表面酸化層を制御したサブミクロン銅薄膜の破壊じん性

Language：Japanese  

Country：Japan  

サブミクロン銅薄膜の疲労き裂開閉口挙動に及ぼす真空環境効果

Language：Japanese  

Country：Japan  

Evaluation of Mechanical Properties of Submicometer-thick Copper Thin Film Using Micro Tensile Specimen

Language：Others  

Country：Japan  

Stress-induced chemical reaction of Ti/Si multilayered nano-films

Language：Others  

Country：Other  

Language：Japanese  

Country：Japan  

Language：Others  

Country：Other  

Language：Others  

Country：Other  

Language：Others  

Country：Other  

Language：Others  

Country：Other  

Language：Others  

Country：Other  

Language：Others  

Country：Other