Abstract

Suppressing strain localization in hard layers was crucial for making gradient alloys ductile. Here, a typical structure in CrFeCoNiMn0.75Cu0.25 high entropy alloy (HEA), which combines gradient distributions along the depth for grain width and twin density, was fabricated using the laser shock peening (LSP) treatment. In situ digital image correlation methods elucidated the mechanisms of the excellent mechanical properties in HEAs treated by LSP for 4 cycles from the perspective of local strain. Dense shear bands were nucleated at the low-strain stage, and remained stable evolution during the entire plastic deformation, thus, leading to an excellent tensile ductility (∼40 %). The plastic deformation incompatibility results in two-dimensional stress states and lateral strain gradient near the plastic-elastic interfaces, which stimulates the interaction and accumulation of micro-defects, thus, improving the strain hardening capacity of alloys. These observations will reveal the mechanistic origin of the gradient structured alloys with superior strength-ductility from a new perspective, which also provide a guidance for optimizing mechanical performances of HEAs.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.