Adiabatic shear localization induced by dynamic recrystallization in an FCC high entropy alloy

Kun Jiang, Jianguo Li, Xiukai Kan, Feng Zhao, Bing Hou, Qiuming Wei, Tao Suo

科研成果: 期刊稿件文章同行评审

58 引用 (Scopus)

摘要

Due to their strong strain hardening, face-centered cubic (FCC) high/medium entropy alloys (H/MEAs) have remarkable resistance to shear localization even under forced dynamic shear. In this work we investigated the dynamic mechanical behavior of an FCC Al0.1CoCrFeNi HEA via a series of split Hopkinson pressure bar (SHPB) experiments at 77 K and room temperature. This HEA exhibited very strong strain hardening capacity, remarkable strain rate sensitivity and moderate temperature dependence. Such a combination of mechanical properties should be strongly unfavorable for adiabatic shear bands (ASBs). However, its dynamic compressive failure at 77 K was found to be caused by crack propagation within the primary ASBs along the directions of maximum shear stress. Detailed examination of the specimens using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) revealed convincing microstructural evidences for massive dynamic recrystallization (DRX) prior to ASB. We suggested that the expansion and coalescence of these DRX softened regions served as the root cause for the occurrence of ASBs and the final catastrophic fracture of specimens. The severe local shear flow, substantial adiabatic temperature rise and extremely fast quenching within the ASB resulted in ultrafine grains therein. Our results and analyses provided a plausible understanding of the formation mechanisms of ASBs in the FCC HEA under impact loading.

源语言英语
文章编号103550
期刊International Journal of Plasticity
162
DOI
出版状态已出版 - 3月 2023

指纹

探究 'Adiabatic shear localization induced by dynamic recrystallization in an FCC high entropy alloy' 的科研主题。它们共同构成独一无二的指纹。

引用此