Hierarchically heterogeneous microstructure and mechanical behavior of the multi-materials prepared by powder severe plastic deformation

Abstract

A heterostructuring strategy is an effective approach for abiding problems referred to as the strength-ductility trade-off. However, tailoring the heterostructure is an arduous problem. This work synthesized hierarchically heterogeneity by combining the eutectic high-entropy alloy (EHEA) and medium-entropy alloy powders through novel powder metallurgy-based severe plastic deformation (P-SPD). EHEA forms nano-scaled heterogeneity composed of FCC and B2, and the mixture of powder types forms micro-scale heterogeneity with hard and soft domains. This hierarchically heterogeneous microstructure leads to strong hetero-deformation-induced strengthening, achieving a yield strength of ∼1.5 GPa. The present P-SPD represents the feasibility of heterostructuring, aiding the development of HEAs.

Keywords

• High-entropy alloys
• high-pressure torsion
• multi-materials
• heterostructures
• mechanical properties