Phase transformation induced plasticity in high-strength hexagonal close packed Co with stacking faults

SCRIPTA MATERIALIA

卷:173

Article

Su, Ruizhe¹  Neffati, Dajla²  Cho, Jaehun¹  Li, Qiang¹  Ding, Jie¹  Wang, Haiyan¹  Kulkarni, Yashashree²  Zhang, Xinghang¹ 

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

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

关键词: Cobalt;    Stacking faults;    Pillar compression;    Phase transformation;    Molecular dynamics simulation;   

DOI  :  10.1016/j.scriptamat.2019.07.030

来源: Elsevier

【 摘 要 】

Deformation twinning and dislocation glide are two primary deformation mechanisms in hexagonal close packed (HCP) metals. Here we show, via in situ micropillar compression tests, that HCP Co pillars with high-density stacking faults exhibit a high yield strength and significant plasticity. Transmission electron microscopy studies reveal the formation of extensive face-centered cubic (FCC) Co phase after deformation. Molecular dynamics simulations confirm the deformation induced phase transformation, and shed light on the deformation mechanisms in HCP Co with pre-existing stacking faults. This study provides new insights into achieving high strength and plasticity in HCP metals via stacking faults and phase transformation. (C) 2019 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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