Reversed strength-ductility relationship in microstructurally flexible high entropy alloy

SCRIPTA MATERIALIA

卷:154

Article

Nene, S. S.¹  Frank, M.¹  Liu, K.¹  Sinha, S.¹  Mishra, R. S.¹  McWilliams, B.²  Cho, K. C.² 

[1] Univ North Texas, Dept Mat Sci & Engn, Ctr Frict Stir Proc, Denton, TX 76207 USA

[2] US Army, Res Lab, Weap & Mat Res Directorate, Aberdeen Proving Ground, MD 21005 USA

关键词: Strength;    Ductility;    Strain-induced transformation;    Twinning;    High entropy alloy;   

DOI  :  10.1016/j.scriptamat.2018.05.043

来源: Elsevier

【 摘 要 】

Conventional high strength alloys lack ductility due to lower work hardening and early onset of damage nucleation. To overcome this deficiency, high entropy alloys (HEAs) enjoy the benefit of metastability of phases to tune the deformation mechanisms for engineering strength and ductility. Inspired by this, here we present friction stir processed Fe40Mn20Co20Cr15Si5 HEA with ultrafine face centered cubic (f.c.c.) gamma grains embedded in a refined hexagonal closed packed (h.c.p) epsilon matrix. Transformation of gamma grains and twinning in e matrix triggered uniform strain partitioning among these phases and sustained work hardening during deformation thereby reversing the conventional strength-ductility trade-off. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free