Enhanced Cocrfeni (Tic) 0.2 High-Entropy Alloy by Thermodynamic Treatment

Abstract

CoCrFeNi based high-entropy alloy has good strength and toughness properties compared to conventional alloys, showing great application prospects in advanced fields such as aerospace structural materials. However, the yield strength of the as-cast CoCrFeNi(TiC)0.2 alloy remains low, limiting its practical application as a high-strength structural material. In this study, we enhance the CoCrFeNi(TiC)0.2 alloy by hot rolling and annealing, which promotes the ultrafine carbide precipitation, partial recrystallization of the alloy matrix, and residual high-density dislocations. The secondphase strengthening of carbide precipitation, fine-grain strengthening of alloy matrix, and dislocation strengthening jointly improve the yield strength. The yield strength of the CoCrFeNi(TiC)0.2 alloy after thermomechanical treatment at 700°C for 1 h has a high yield strength of 865 MPa, ultimate tensile strength of 1047 MPa and uniform elongation of 6.8%. This study provides a theoretical guidance for the composition and technological design of high performance alloys.

Keywords: High-entropy alloy, carbide, mechanical properties, thermomechanical treatment