Deformation mechanisms in FCC Co dominated by high-density stacking faults

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:736

Article

Su, R.¹  Neffati, D.²  Xue, S.¹  Li, Q.¹  Fan, Z.¹  Liu, Y.³  Wang, H.¹  Kulkarni, Y.²  Zhang, X.¹ 

[1] Purdue Univ, Dept Mat Engn, W Lafayette, IN 47907 USA

[2] Univ Houston, Dept Mech Engn, Houston, TX 77204 USA

[3] Shanghai Jiao Tong Univ, State Key Lab Met Matrix Composites, Sch Mat Sci & Engn, Shanghai 200240, Peoples R China

关键词: Cobalt;    In situ compression;    Stacking faults;    Strain rate sensitivity;    Molecular dynamics;   

DOI  :  10.1016/j.msea.2018.08.057

来源: Elsevier

【 摘 要 】

It has been known that twin boundaries dominate the plasticity of nanotwinned metals. However, the role of stacking faults on the deformation mechanisms in face-centered-cubic (FCC) metals is less well understood. Here we investigate the deformation mechanisms of FCC Co with high-density stacking faults using in situ micropillar compression and atomistic simulations. In situ compression tests show a prominent strain rate dependence, with either strain softening or strain hardening observed at different strain rates. Molecular dynamics simulations reveal that the stacking faults and partial dislocations dominate the plastic deformation of FCC Co. Abundant dislocation junctions form at high strain rate, leading to strengthening.

【 授权许可】

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