Dynamic transformation(DT)of austenite(γ)to ferrite(α)in the hot deformation of various carbon steels was widely investigated.However,the nature of DT remains unclear due to the lack of quantitative analysis of stre...Dynamic transformation(DT)of austenite(γ)to ferrite(α)in the hot deformation of various carbon steels was widely investigated.However,the nature of DT remains unclear due to the lack of quantitative analysis of stress partitioning between two phases and the uncertainty of local distribution of substitu-tional elements at the interface in multi-component carbon steels used in the previous studies.Therefore,in the present study,a binary Fe-Ni alloy withα+γduplex microstructure in equilibrium was prepared and isothermally compressed inα+γtwo-phase region to achieve a quantitative analysis of microstruc-ture evolution,stress partitioning,and thermodynamics during DT.γtoαDT during isothermal compres-sion andαtoγreverse transformation on isothermal annealing under unloaded condition after deforma-tion were accompanied by Ni partitioning.The lattice strains during thermomechanical processing were obtained via in-situ neutron diffraction measurement,based on which the stress partitioning behavior betweenγandαwas discussed by using the generalized Hooke’s law.A thermodynamic framework for the isothermal deformation in solids was established based on the basic laws of thermodynamics,and it was shown that the total Helmholtz free energy change in the deformable material during the isothermal process should be smaller than the work done to the deformable material.Under the present thermody-namic framework,the microstructure evolution in the isothermal compression of Fe-14Ni alloy was well explained by considering the changes in chemical free energy,plastic and elastic energies,and the work done to the material.In addition,the stabilization of the softαphase in Fe-14Ni alloy by deformation was rationalized since theγtoαtransformation decreased the total Helmholtz free energy by decreasing the elastic and dislocation energies.展开更多
Hydrogen embrittlement(HE)in 2 GPa-grade press-hardened steel(PHS)has posed a great risk to its lightweighting application in automotive crash-resistant components.While conventional slow strain rate tensile tests sho...Hydrogen embrittlement(HE)in 2 GPa-grade press-hardened steel(PHS)has posed a great risk to its lightweighting application in automotive crash-resistant components.While conventional slow strain rate tensile tests show that the precharged hydrogen concentration of 3.5 wppm induces a severe loss in strength and ductility,the high strain rate tests conducted at 1–103 s−1 that simulate the crash condition demonstrate no loss in strength and a minimal loss in ductility.Such strain rate dependency cannot be exclusively explained via hydrogen diffusion and redistribution to susceptible prior austenite grain boundaries,as the tensile testing of precharged samples with jumping strain rates offers a sufficient redistribution period at slow-strain-rate loading,but does not necessarily lead to a high level of HE afterwards.Detailed fractography analysis acknowledges that hydrogen-induced microcracks nucleated within early deformation stages are directly responsible for the high HE susceptibility of all test conditions.A phase-field simulation comprising 2 GPa-grade PHS's microstructure features and the hydrogen diffusion under tested loading conditions is applied.The calculation reveals that the hydrogen redistribution behavior is spatially confined to the crack tip areas but to a much greater extent.It thus facilitates continuous crack growth following the main crack with minimal plastic deformation and avoids branching to form secondary cracks.The combined experiments and modeling highlight the vital role of microcracks in the HE performance of 2 GPa-grade PHS,upon which the safety factor of HE in high-strength martensitic steels shall be established.展开更多
We have systematically investigated the microstructures of as-cast Mg_(97.49)Ho_(1.99)Cu_(0.43)Zr_(0.09)alloy by atomic resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM), r...We have systematically investigated the microstructures of as-cast Mg_(97.49)Ho_(1.99)Cu_(0.43)Zr_(0.09)alloy by atomic resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM), revealing the coexistence of 18R, 14H and 24R long period stacking/order(LPSO) phases with fully coherent interfaces along step-like composition gradient in a blocky intermetallic compound distributed at grain boundary. The short-range order(SRO) L1_(2)-type Cu_(6)Ho_(8)clusters embedded across AB’C’A-stacking fault layers are directly revealed at atomic scale. Importantly, the order degree of SRO clusters in the present dilute alloy is significant lower than previous 6M and 7M in-plane order reported in ternary Mg-TM(transition metal)-RE(rare earth) alloys, which can be well matched by 9M in-plane order. This directly demonstrates that SRO in-plane L1_(2)-type clusters can be expanded into more dilute composition regions bounded along the definite TM/RE ratio of 3/4. In addition, the estimated chemical compositions of solute enriched stacking fault(SESF) in all LPSO variants are almost identical with the ideal SESF composition of 9M in-plane order, regardless of the type of LPSO phases. The results further support the viewpoint that robust L1_(2)-type TM_(6)RE_(8)clusters play an important role in governing LPSO phase formation.展开更多
The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically investigated.In the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morpho...The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically investigated.In the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morphologies are identified as Mg_(3)Sm phase. In addition to Mg_(3)RE phase, Mg_(5)RE phase originated from Gd addition is observed in Gd-modified alloys. It should be noted that the lattice parameters of all the observed intermetallic compounds are significantly reduced by Zn segregation. The segregation behavior of Zn in Mg_(3)Sm phase is inhibited to some extent by Gd addition due to the electronegativity difference between Sm/Gd and Zn elements. In addition, the increased Gd content effectively leads to much more accumulation of solute atoms in front of the liquid-solid interface during solidification, which can prominently promote nucleation in liquid region and then refine grains. The tensile yield stress of the present alloys is thus improved with increasing Gd addition. Finally, Gd-modified alloys exhibit significantly age-hardening effect, which can be mainly attributed to the high-volume fraction and high density nano-scale precipitates.展开更多
This paper reported an effectiveness of pre-cold rolling-induced{332}／113[twins combined with subsequent isothermal x-phase formation for enhancement of uniform elongation in a b-type Ti–15Mo alloy with high yield s...This paper reported an effectiveness of pre-cold rolling-induced{332}／113[twins combined with subsequent isothermal x-phase formation for enhancement of uniform elongation in a b-type Ti–15Mo alloy with high yield strength level.Mechanical{332}／113[twins were induced by cold rolling with an thickness reduction of 5%,which had little effect on x-phase precipitation after aging at 573 K for 3.6 ks.Twinning after the cold rolling was further activated during tensile deformation,even with the presence of isothermal x-phase.This combination of twins and x-phase enhanced uniform elongation from 0 to 9%at yield strength level of 890 MPa.The high yield strength was mainly dominated by dislocation slip due to the isothermal x-phase formation,and early onset of plastic instability after yielding was hindered due to the pre-cold rolling-induced twins.Dynamic microstructural refinement was induced by further twinning activation during deformation,which resulted in high work hardening rate corresponding enhancement of uniform elongation.展开更多
Novel carbon/glass hybrid thermoplastic composite rods having different carbon/glass ratios (24K1P,24K2P,and 24K3P) are commercially fabricated.The transverse compressive properties of these three hybrid rods were inv...Novel carbon/glass hybrid thermoplastic composite rods having different carbon/glass ratios (24K1P,24K2P,and 24K3P) are commercially fabricated.The transverse compressive properties of these three hybrid rods were investigated.The load-displacement curve showed large nonlinear behavior and a complicated shape.In the initial stage,the load gradually increased by increasing the deformation.In the second stage,the load-displacement relation was almost linearly proportional to the displacement (stable deformation region).Subsequently,the slope decreased slightly,before the load-displacement curve showed a clear slope increase as the deformation proceeded.The fracture behavior of the hybrid rods was examined using a digital microscope.The observed fracture paths formed almost straight lines running through the loading point,the center of the cross section of carbon fiber bundles/thermoplastic epoxy,as well as the interface between the glass fiber bundles/thermoplastic epoxy and the carbon fiber bundles/thermoplastic epoxy.展开更多
The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)<sub>2</sub> with and without 3% NaCl using SECM and correlated ...The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)<sub>2</sub> with and without 3% NaCl using SECM and correlated with EIS. The results obtained from EIS analysis showed that the corrosion resistance of scratched epoxy coated carbon steel decreases in Cl<sup>-</sup> containing solution as the increase in wet/ dry corrosion cycles. This was indicated by decrease in film resistance (R<sub>f</sub>) and charge transfer resistance (R<sub>ct</sub>), while the coated steel maintain the resistance values in saturated Ca(OH)<sub>2</sub>, most of which recovered after drying. The corrosion process was monitored using SECM by setting the tip potential at -0.70 V vs Ag/AgCl, where the consumption of dissolved oxygen occurred at the surface of test sample. The consumption of dissolved oxygen current (I’<sub>oxy-c</sub>) values was increased during the immersion in a solution with 3% NaCl. However, in wet/dry corrosion cycles, I’<sub>oxy-c</sub> was decreased due to the coverage of hydroxides/oxides at scratch area which suppressed the consumption of dissolved O<sub>2</sub>. It was found that the continuous decrease in corrosion was mainly attributed to continuous formation of corrosion products at anodic spots.展开更多
Silicon carbide(SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abu...Silicon carbide(SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abundant water as oxidant. After this smoothening process, the tribo-surface is well polished, a closely mated tribo-gap naturally forms, and an ultra-low friction state is built. However, water in the tribo-gap could be insufficient in industrial applications, e.g., the seal gap in mechanical seals. In this study, the tribo-chemical smoothening behavior in such environment was researched. A surface-contact reciprocating test was used to simulate the aqueous environment where water was insufficient. After tests, compared to the published results from the point-contact tests, the same ultra-low friction state was achieved. A part of the tribo-surface was tribo-chemically smoothened. The obtained smoothened surface microstructure was consistent with the published information. Meanwhile, severe abrasive wear occurred. A porous oxygen-rich layer was found existing beneath the abrasion-induced grooves, in which numerous smashed wear debris adhered on the worn surfaces. We concluded that the shortage of water initiated the severe abrasion, meanwhile the generated wear debris aggravated the wear condition. This understanding is instructive for developing new methods to avoid the severe abrasion in the same water insufficient environment.展开更多
The physical origins of the mechanical properties of Fe-rich Si alloys are investigated by combining electronic structure calculations with statistical mechanics means such as the cluster variation method,molecular dy...The physical origins of the mechanical properties of Fe-rich Si alloys are investigated by combining electronic structure calculations with statistical mechanics means such as the cluster variation method,molecular dynamics simulation,etc,applied to homogeneous and heterogeneous systems.Firstly,we examined the elastic properties based on electronic structure calculations in a homogeneous system and attributed the physical origin of the loss of ductility with increasing Si content to the combined effects of magneto-volume and D03 ordering.As a typical example of a heterogeneity forming a microstructure,we focus on grain boundaries,and segregation behavior of Si atoms is studied through high-precision electronic structure calculations.Two kinds of segregation sites are identified:looser and tighter sites.Depending on the site,different segregation mechanisms are revealed.Finally,the dislocation behavior in the Fe-Si alloy is investigated mainly by molecular dynamics simulations combined with electronic structure calculations.The solid-solution hardening and softening are interpreted in terms of two kinds of energy barriers for kink nucleation and migration on a screw dislocation line.Furthermore,the clue to the peculiar work hardening behavior is discussed based on kinetic Monte Carlo simulations by focusing on the preferential selection of slip planes triggered by kink nucleation.展开更多
基金by JST FOREST Program(Grant No.JPMJFR203W,Japan)MEXT through Grant-in-Aid for Scientific Research(B)(No.19H02473,2019-2021)+2 种基金Grant-in-Aid for Scientific Research on Innovative Areas(Research in a proposed research area)(No.18H05456,2018-2022)the partial support through the research grant funded by the Amada Foundation(2022-2023)the financial support from the Amada Foundation(AF-2022017-B2).L.L.gratefully acknowledges the financial support provided by China Scholarship Council(No.201806295030)and thanks Dr.Elango Chandiran。
文摘Dynamic transformation(DT)of austenite(γ)to ferrite(α)in the hot deformation of various carbon steels was widely investigated.However,the nature of DT remains unclear due to the lack of quantitative analysis of stress partitioning between two phases and the uncertainty of local distribution of substitu-tional elements at the interface in multi-component carbon steels used in the previous studies.Therefore,in the present study,a binary Fe-Ni alloy withα+γduplex microstructure in equilibrium was prepared and isothermally compressed inα+γtwo-phase region to achieve a quantitative analysis of microstruc-ture evolution,stress partitioning,and thermodynamics during DT.γtoαDT during isothermal compres-sion andαtoγreverse transformation on isothermal annealing under unloaded condition after deforma-tion were accompanied by Ni partitioning.The lattice strains during thermomechanical processing were obtained via in-situ neutron diffraction measurement,based on which the stress partitioning behavior betweenγandαwas discussed by using the generalized Hooke’s law.A thermodynamic framework for the isothermal deformation in solids was established based on the basic laws of thermodynamics,and it was shown that the total Helmholtz free energy change in the deformable material during the isothermal process should be smaller than the work done to the deformable material.Under the present thermody-namic framework,the microstructure evolution in the isothermal compression of Fe-14Ni alloy was well explained by considering the changes in chemical free energy,plastic and elastic energies,and the work done to the material.In addition,the stabilization of the softαphase in Fe-14Ni alloy by deformation was rationalized since theγtoαtransformation decreased the total Helmholtz free energy by decreasing the elastic and dislocation energies.
基金support from the National Natural Science Foundation of China(No.52130102)the National Key Research and Development Program of China(No.2019YFA0209900)+5 种基金the Research Grants Council of Hong Kong(No.R7066–18)the Guangzhou Municipal Science and Technology Project(No.202007020007)the Guangdong Basic and Applied Basic Research Foundation of China(No.2020B1515130007)Lunhua He and Mingxin Huang acknowledge the support from the International Partnership Program of the Chinese Academy of Sciences(No.113111KYSB20190029)the key program of the Chinese Academy of Sciences(CAS)China Spallation Neutron Source(CSNS)is acknowledged for supporting neutron diffraction experiments using the General Purpose Powder Diffractometer(GPPD).
文摘Hydrogen embrittlement(HE)in 2 GPa-grade press-hardened steel(PHS)has posed a great risk to its lightweighting application in automotive crash-resistant components.While conventional slow strain rate tensile tests show that the precharged hydrogen concentration of 3.5 wppm induces a severe loss in strength and ductility,the high strain rate tests conducted at 1–103 s−1 that simulate the crash condition demonstrate no loss in strength and a minimal loss in ductility.Such strain rate dependency cannot be exclusively explained via hydrogen diffusion and redistribution to susceptible prior austenite grain boundaries,as the tensile testing of precharged samples with jumping strain rates offers a sufficient redistribution period at slow-strain-rate loading,but does not necessarily lead to a high level of HE afterwards.Detailed fractography analysis acknowledges that hydrogen-induced microcracks nucleated within early deformation stages are directly responsible for the high HE susceptibility of all test conditions.A phase-field simulation comprising 2 GPa-grade PHS's microstructure features and the hydrogen diffusion under tested loading conditions is applied.The calculation reveals that the hydrogen redistribution behavior is spatially confined to the crack tip areas but to a much greater extent.It thus facilitates continuous crack growth following the main crack with minimal plastic deformation and avoids branching to form secondary cracks.The combined experiments and modeling highlight the vital role of microcracks in the HE performance of 2 GPa-grade PHS,upon which the safety factor of HE in high-strength martensitic steels shall be established.
基金supported by JSPS KAKENHI for Scientific Research on Innovative Areas “Materials Science of a Millefeuille Structure (Grant Nos. JP18H05475, JP18H05479)”“Nanotechnology Platform” of the MEXT, Japan+1 种基金supported by Grant-in-Aid for JSPS Fellows (JP19F19775)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization (RERU2020012)。
文摘We have systematically investigated the microstructures of as-cast Mg_(97.49)Ho_(1.99)Cu_(0.43)Zr_(0.09)alloy by atomic resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM), revealing the coexistence of 18R, 14H and 24R long period stacking/order(LPSO) phases with fully coherent interfaces along step-like composition gradient in a blocky intermetallic compound distributed at grain boundary. The short-range order(SRO) L1_(2)-type Cu_(6)Ho_(8)clusters embedded across AB’C’A-stacking fault layers are directly revealed at atomic scale. Importantly, the order degree of SRO clusters in the present dilute alloy is significant lower than previous 6M and 7M in-plane order reported in ternary Mg-TM(transition metal)-RE(rare earth) alloys, which can be well matched by 9M in-plane order. This directly demonstrates that SRO in-plane L1_(2)-type clusters can be expanded into more dilute composition regions bounded along the definite TM/RE ratio of 3/4. In addition, the estimated chemical compositions of solute enriched stacking fault(SESF) in all LPSO variants are almost identical with the ideal SESF composition of 9M in-plane order, regardless of the type of LPSO phases. The results further support the viewpoint that robust L1_(2)-type TM_(6)RE_(8)clusters play an important role in governing LPSO phase formation.
基金JSPS KAKENHI for Scientific Research on Innovative Areas“Materials Science of a Mille-feuille Structure(Grant Numbers JP18H05475,JP18H05479)”the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(RERU2020012)+1 种基金“Nanotechnology Platform”of the MEXT,JapanGrant-in-Aid for JSPS Fellows(JP19F19775)。
文摘The effect of Gd content on the microstructure and tensile properties of as-cast Mg-Sm-Zn-Zr alloy has been systematically investigated.In the Mg-3Sm-0.5Zn-0.5Zr alloy, the intermetallic compounds with multiple morphologies are identified as Mg_(3)Sm phase. In addition to Mg_(3)RE phase, Mg_(5)RE phase originated from Gd addition is observed in Gd-modified alloys. It should be noted that the lattice parameters of all the observed intermetallic compounds are significantly reduced by Zn segregation. The segregation behavior of Zn in Mg_(3)Sm phase is inhibited to some extent by Gd addition due to the electronegativity difference between Sm/Gd and Zn elements. In addition, the increased Gd content effectively leads to much more accumulation of solute atoms in front of the liquid-solid interface during solidification, which can prominently promote nucleation in liquid region and then refine grains. The tensile yield stress of the present alloys is thus improved with increasing Gd addition. Finally, Gd-modified alloys exhibit significantly age-hardening effect, which can be mainly attributed to the high-volume fraction and high density nano-scale precipitates.
基金financially supported by the National Natural Science Foundation of China (Grant No. 51471040)
文摘This paper reported an effectiveness of pre-cold rolling-induced{332}／113[twins combined with subsequent isothermal x-phase formation for enhancement of uniform elongation in a b-type Ti–15Mo alloy with high yield strength level.Mechanical{332}／113[twins were induced by cold rolling with an thickness reduction of 5%,which had little effect on x-phase precipitation after aging at 573 K for 3.6 ks.Twinning after the cold rolling was further activated during tensile deformation,even with the presence of isothermal x-phase.This combination of twins and x-phase enhanced uniform elongation from 0 to 9%at yield strength level of 890 MPa.The high yield strength was mainly dominated by dislocation slip due to the isothermal x-phase formation,and early onset of plastic instability after yielding was hindered due to the pre-cold rolling-induced twins.Dynamic microstructural refinement was induced by further twinning activation during deformation,which resulted in high work hardening rate corresponding enhancement of uniform elongation.
文摘Novel carbon/glass hybrid thermoplastic composite rods having different carbon/glass ratios (24K1P,24K2P,and 24K3P) are commercially fabricated.The transverse compressive properties of these three hybrid rods were investigated.The load-displacement curve showed large nonlinear behavior and a complicated shape.In the initial stage,the load gradually increased by increasing the deformation.In the second stage,the load-displacement relation was almost linearly proportional to the displacement (stable deformation region).Subsequently,the slope decreased slightly,before the load-displacement curve showed a clear slope increase as the deformation proceeded.The fracture behavior of the hybrid rods was examined using a digital microscope.The observed fracture paths formed almost straight lines running through the loading point,the center of the cross section of carbon fiber bundles/thermoplastic epoxy,as well as the interface between the glass fiber bundles/thermoplastic epoxy and the carbon fiber bundles/thermoplastic epoxy.
文摘The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)<sub>2</sub> with and without 3% NaCl using SECM and correlated with EIS. The results obtained from EIS analysis showed that the corrosion resistance of scratched epoxy coated carbon steel decreases in Cl<sup>-</sup> containing solution as the increase in wet/ dry corrosion cycles. This was indicated by decrease in film resistance (R<sub>f</sub>) and charge transfer resistance (R<sub>ct</sub>), while the coated steel maintain the resistance values in saturated Ca(OH)<sub>2</sub>, most of which recovered after drying. The corrosion process was monitored using SECM by setting the tip potential at -0.70 V vs Ag/AgCl, where the consumption of dissolved oxygen occurred at the surface of test sample. The consumption of dissolved oxygen current (I’<sub>oxy-c</sub>) values was increased during the immersion in a solution with 3% NaCl. However, in wet/dry corrosion cycles, I’<sub>oxy-c</sub> was decreased due to the coverage of hydroxides/oxides at scratch area which suppressed the consumption of dissolved O<sub>2</sub>. It was found that the continuous decrease in corrosion was mainly attributed to continuous formation of corrosion products at anodic spots.
文摘Silicon carbide(SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abundant water as oxidant. After this smoothening process, the tribo-surface is well polished, a closely mated tribo-gap naturally forms, and an ultra-low friction state is built. However, water in the tribo-gap could be insufficient in industrial applications, e.g., the seal gap in mechanical seals. In this study, the tribo-chemical smoothening behavior in such environment was researched. A surface-contact reciprocating test was used to simulate the aqueous environment where water was insufficient. After tests, compared to the published results from the point-contact tests, the same ultra-low friction state was achieved. A part of the tribo-surface was tribo-chemically smoothened. The obtained smoothened surface microstructure was consistent with the published information. Meanwhile, severe abrasive wear occurred. A porous oxygen-rich layer was found existing beneath the abrasion-induced grooves, in which numerous smashed wear debris adhered on the worn surfaces. We concluded that the shortage of water initiated the severe abrasion, meanwhile the generated wear debris aggravated the wear condition. This understanding is instructive for developing new methods to avoid the severe abrasion in the same water insufficient environment.
基金supported by the JST Industry-Academia Collaborative Programs,“Materials Strength from Hamiltonian”,and by the Elements Strategy Initiative for Structural Materials(ESISM)through MEXT,Japansupported by a Grant-in-Aid for Scientific Research on Innovative Area“Bulk Nanostructured Metals”and by the Computational Materials Science Initiative(CMSI),MEXT,Japanthe K computer provided by the RIKEN Advanced Institute for Computational Science through the HPCI System Research project(Project ID:hp130016,hp140233,hp150235).
文摘The physical origins of the mechanical properties of Fe-rich Si alloys are investigated by combining electronic structure calculations with statistical mechanics means such as the cluster variation method,molecular dynamics simulation,etc,applied to homogeneous and heterogeneous systems.Firstly,we examined the elastic properties based on electronic structure calculations in a homogeneous system and attributed the physical origin of the loss of ductility with increasing Si content to the combined effects of magneto-volume and D03 ordering.As a typical example of a heterogeneity forming a microstructure,we focus on grain boundaries,and segregation behavior of Si atoms is studied through high-precision electronic structure calculations.Two kinds of segregation sites are identified:looser and tighter sites.Depending on the site,different segregation mechanisms are revealed.Finally,the dislocation behavior in the Fe-Si alloy is investigated mainly by molecular dynamics simulations combined with electronic structure calculations.The solid-solution hardening and softening are interpreted in terms of two kinds of energy barriers for kink nucleation and migration on a screw dislocation line.Furthermore,the clue to the peculiar work hardening behavior is discussed based on kinetic Monte Carlo simulations by focusing on the preferential selection of slip planes triggered by kink nucleation.
