TY - JOUR

T1 - Enhanced mechanical performance of gradient-structured CoCrFeMnNi high-entropy alloys induced by industrial shot-blasting

AU - Zhang, Ming Zhi

AU - Zhang, Kun

AU - Song, Kaikai

AU - Zou, Xiao Yu

AU - Song, Wei Dong

AU - Li, Ke Feng

AU - Hu, Li-Na

AU - Zhang, Ze-Qun

AU - Eckert, Jürgen

N1 - Publisher Copyright: © 2022, Youke Publishing Co.,Ltd.

PY - 2022/12/7

Y1 - 2022/12/7

N2 - In this study, CoCrFeMnNi high-entropy alloys (HEAs) with a surface gradient nanostructure were produced using industrial shot blasting, which improved their mechanical properties compared to the untreated alloy. The severely plastically deformed (SPD) surface layer had a multi-scale hierarchical structure with a high density of stacking faults, deformation nanotwins, and amorphous domains. The depth of the SPD layer steadily increased as the shot-blasting time increased. The differences in the microhardness and tensile strength before and after shot-blasting demonstrated the significant effect of the SPD layer on the mechanical performance. The microhardness of the homogenized HEA was ~ 5 GPa. In comparison, the maximum microhardness of the specimens after 20 min of shot blasting was ~ 8.0 GPa at the surface. The yield strength also improved by 178%, and a large ductility of ~ 36% was retained. Additional nanograin boundary, stacking fault, and twin strengthening within the gradient-nanostructured surface layer caused the strength to increase. During tensile deformation, strain concentration began at the surface of the specimen and gradually spread to the interior. Thus, the gradient-nanostructured surface layer with improved strain hardening can prevent early necking and ensure steady plastic deformation so that high toughness is achieved.

AB - In this study, CoCrFeMnNi high-entropy alloys (HEAs) with a surface gradient nanostructure were produced using industrial shot blasting, which improved their mechanical properties compared to the untreated alloy. The severely plastically deformed (SPD) surface layer had a multi-scale hierarchical structure with a high density of stacking faults, deformation nanotwins, and amorphous domains. The depth of the SPD layer steadily increased as the shot-blasting time increased. The differences in the microhardness and tensile strength before and after shot-blasting demonstrated the significant effect of the SPD layer on the mechanical performance. The microhardness of the homogenized HEA was ~ 5 GPa. In comparison, the maximum microhardness of the specimens after 20 min of shot blasting was ~ 8.0 GPa at the surface. The yield strength also improved by 178%, and a large ductility of ~ 36% was retained. Additional nanograin boundary, stacking fault, and twin strengthening within the gradient-nanostructured surface layer caused the strength to increase. During tensile deformation, strain concentration began at the surface of the specimen and gradually spread to the interior. Thus, the gradient-nanostructured surface layer with improved strain hardening can prevent early necking and ensure steady plastic deformation so that high toughness is achieved.

KW - Deformation mechanism

KW - Gradient structure

KW - High-entropy alloy

KW - Mechanical property

KW - Shot blasting

UR - http://www.scopus.com/inward/record.url?scp=85143418334&partnerID=8YFLogxK

U2 - 10.1007/s12598-022-02164-1

DO - 10.1007/s12598-022-02164-1

M3 - Article

AN - SCOPUS:85143418334

VL - 42.2023

SP - 982

EP - 993

JO - Rare Metals

JF - Rare Metals

SN - 1001-0521

IS - March

ER -