Tunable mechanical property and strain hardening behavior of a single-phase CoFeNi2V0.5Mo0.2 high entropy alloy

A large variety of mechanical properties have been achieved in a single-phase CoFeNi2V0.5Mo0.2 high entropy alloy (HEA) with various thermo-mechanical treatments. The HEA always exhibits an excellent strength-ductility synergy after different annealing processes. In particular, the material with fully recrystallized microstructure displays a yield strength of 485 MPa and a high ductility of over 60%, superior to most conventional alloys and HEAs. Results of microstructural analysis indicate that the dislocation dominated deformation mechanism involving dislocation multiplication and interactions through successive planar slip and cross slip serves to enhance the strain hardening capacity, which delays the fracture of the alloy and contributes to the excellent strength and ductility combination.