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

Ming Zhi Zhang, Kun Zhang, Kaikai Song, Xiao Yu Zou, Wei Dong Song, Ke Feng Li, Li-Na Hu, Ze-Qun Zhang, Jürgen Eckert

Research output: Contribution to journalArticleResearchpeer-review


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.
Original languageEnglish
Pages (from-to)982-993
Number of pages12
JournalRare Metals
Issue numberMarch
Publication statusPublished - 7 Dec 2022

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  • Deformation mechanism
  • Gradient structure
  • High-entropy alloy
  • Mechanical property
  • Shot blasting

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