Search Results - "Han, S.Z."

Simultaneous increase in electrical conductivity and fatigue strength of Cu-Ni-Si alloy by utilizing discontinuous precipitates by Goto, M., Yamamoto, T., Han, S.Z., Utsunomiya, T., Kim, S., Kitamura, J., Ahn, J.H., Lim, S.H., Lee, J.

“…•Ni-6Si-1.5Ni alloy with discontinuous precipitates (DPs) produced by overaging was cold rolled.•Conductivity of cold rolled specimen (CR-DP) was 1.64 times of…”
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Crack initiation mechanism in ultrafine-grained copper fabricated by severe plastic deformation in the high-cycle fatigue regime by Goto, M., Yamamoto, T., Han, S.Z., Lim, S.H., Kim, S., Ahn, J.-H., Lee, S.J., Yakushiji, T., Lee, J.

“…Ultrafine grained (UFG) metals processed by the severe plastic deformation technique have an unusual microstructure of ‘high energy/non-equilibrium’ state. It…”
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Role of microstructure on initiation and propagation of fatigue cracks in precipitate strengthened Cu–Ni–Si alloy by Goto, M., Han, S.Z., Lim, S.H., Kitamura, J., Fujimura, T., Ahn, J.-H., Yamamoto, T., Kim, S., Lee, J.

“…•Fatigue cracks originated from GBs, followed by the growth along the slip planes.•Heterogeneously precipitated δ-Ni2Si particles and PFZs were formed around…”
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Formation mechanism of inclined fatigue-cracks in ultrafine-grained Cu processed by equal channel angular pressing by Goto, M., Han, S.Z., Yamamoto, T., Kitamura, J., Ahn, J.H., Yakushiji, T., Kim, S.S., Lee, J.

“…•At high stresses, surface cracks grew along the shear plane of the final pressing.•At high stresses, the aspect ratio was 0.38 and 1.1 for the zx- and…”
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Fatigue crack initiation and propagation behaviors of solution-treated and air-cooled Cu-6Ni-1.5Si alloy strengthened by precipitation hardening by Goto, M., Iwamura, T., Han, S.Z., Kim, S., Yamamoto, T., Lim, S.H., Ahn, J-H., Kitamura, J., Lee, J.

“…•Air cooling (AC) instead of water quenching (WQ) was applied after SHT.•Fatigue strength of AC specimen was 1.1 times greater than WQ one.•Electrical…”
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Crack growth rate of inclined and deflected surface-cracks in round-bar specimens of copper processed by equal channel angular pressing under cyclic loading by Goto, M., Yamamoto, T., Han, S.Z., Kim, S., Ahn, J-H., Kitamura, J., Iwamura, T., Lee, J.

“…•Cracks grew along the ECAP-shear plane, forming a 45° inclined/deflected crack.•The crack growth rate was discussed by the comparative-SIF,KV, under mixed…”
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Effects of grain refinement due to severe plastic deformation on the growth behavior of small cracks in copper by Goto, M., Kamil, K., Han, S.Z., Euh, K., Kim, S.S., Yokoho, Y.

“…► The difference in the growth behavior tendency between CG and UFG copper occurred at an extremely low CGR (dl/dN<10−6mm/c). ► A quantitative model describing…”
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Fatigue-induced grain coarsening and crack growth behavior in ultrafine-grained copper under different loading histories by Goto, M., Kamil, K., Han, S.Z., Euh, K., Kim, S.S., Lee, J.

“…► At high-stress, the crack path was 45° inclined direction to the loading axis (LA). ► At low-stress, the crack grew perpendicular to the LA. ► At low-to-high…”
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The role of mixed-mode deformation at the crack tip on shear banding and crack propagation of ultrafine-grained copper by Goto, M., Han, S.Z., Ahn, J.H., Yakushiji, T., Euh, K., Kim, S.S., Lee, J.

“…•The crack paths was 45° inclined to the loading axis in the Y-plane.•The crack paths was 90° inclined to the loading axis in the Z-plane.•The aspect ratios…”
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Formation behavior of different topographies of crack growth path under high and low cyclic stresses in ultrafine-grained copper by Goto, M., Kamil, K., Han, S.Z., Euh, K., Yokoho, Y., Kim, S.S.

“…Fatigue tests of ultrafine-grained copper specimens were conducted. The crack growth direction under constant stress depended on the magnitude of the stress…”
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Formation process of shear bands and protrusions in ultrafine grained copper under cyclic stresses by Goto, M., Han, S.Z., Yakushiji, T., Lim, C.Y., Kim, S.S.

“…Ultrafine grained copper processed by equal channel angular pressing was fatigued at two constant stress amplitudes: σ a = 240 and 120 MPa (corresponding…”
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The effect of microstructural inhomogeneity on the growth paths of surface-cracks in copper processed by equal channel angular pressing by Goto, M., Ando, Y., Han, S.Z., Kim, S.S., Kawagoishi, N., Euh, K.

“…The growth behavior of cracks is monitored on specimens of ultrafine grained copper produced by equal channel angular pressing. Temporary retardation of crack…”
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Growth mechanism of a small surface crack of ultrafine-grained copper in a high-cycle fatigue regime by Goto, M., Han, S.Z., Kim, S.S., Ando, Y., Kawagoishi, N.

“…High-cycle fatigue tests were carried out on specimens of ultrafine-grained copper produced by equal channel angular pressing. The growth behavior of a small…”
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Significance of non-equilibrium grain boundaries in surface damage formation of ultrafine-grained copper in high-cycle fatigue by Goto, M., Han, S.Z., Kim, S.S., Kawagoishi, N., Lim, C.Y.

“…High-cycle fatigue tests were carried out on specimens of ultrafine-grained copper both after equal channel angular pressing and after subsequent annealing at…”
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Effect of trace phosphorous on tensile behavior of accumulative roll bonded oxygen-free copper by Jang, Y.H., Kim, S.S., Han, S.Z., Lim, C.Y., Kim, C.J., Goto, M.

“…In the present study, the effect of trace phosphorous on the tensile behavior of nano grain-sized oxygen free copper produced by accumulative roll bonding was…”
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Corrigendum to “Stress-dependent opening- and shear-mode propagation behavior of fatigue cracks in ultrafine-grained Cu fabricated by equal channel angular pressing”. [Int. J. Fatigue 142 (2021) 105978] by Goto, M., Yamamoto, T., Han, S.Z., Kim, S., Kitamura, J., Yakushiji, T., Ahn, J.-H., Takanami, R., Utsunomiya, T., Lee, J.

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Stress-dependent opening- and shear-mode propagation behavior of fatigue cracks in ultrafine-grained Cu fabricated by equal channel angular pressing by Goto, M., Yamamoto, T., Han, S.Z., Kim, S., Kitamura, J., Yakushiji, T., Ahn, J-H., Takanami, R., Utsunomiya, T., Lee, J.

“…•At σa ≥ 180 MPa, the crack path was inclined 45° to the loading axis.•At σa ≤ 160 MP, the crack path was nearly perpendicular to the loading axis.•The change…”
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Microstructure-dependent fatigue behavior of aged Cu-6Ni-1.5Si alloy with discontinuous/cellular precipitates by Goto, M., Yamamoto, T., Han, S.Z., Lim, S.H., Kim, S., Iwamura, T., Kitamura, J., Ahn, J.-H., Yakushiji, T., Lee, J.

“…The effect of microstructure on the fatigue strength of age-hardened Cu–6Ni–1.5Si alloy was investigated in this study. The aging was conducted at 500 °C for…”
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S–N plots and related phenomena of ultrafine grained copper with different stages of microstructural evolution by Goto, M., Han, S.Z., Kitamura, J., Yakushiji, T., Ahn, J.H., Kim, S.S., Baba, M., Yamamoto, T., Lee, J.

“…•Fatigue life at stresses corresponding to lifetime from 2×104 to 2×107cycles depended on ECAP-pass-number.•The fatigue life decreased according to the…”
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High-cycle fatigue strength and small-crack growth behavior of ultrafine-grained copper with post-ECAP annealing by Goto, M., Teshima, N., Han, S.Z., Euh, K., Yakushiji, T., Kim, S.S., Lee, J.

“…•New results on unique properties of fatigue strength and crack growth of UFG copper due to post ECAP annealing were shown.•Fatigue life of post-ECAP annealed…”
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