Influence of Annealing on Microstructure and Mechanical Properties of Equiatomic CoCrNiTiV 3d Transition Metal High Entropy Alloy Ingots

抄録

A novel equiatomic CoCrNiTiV high entropy alloy was fabricated by a vacuum arc-melting, and investigated from the view of phase component, microstructure, mechanical properties. The results experimentally displayed that a typical single phase BCC solid solution was acquired in the as-cast CoCrNiTiV alloy, while another BCC phase together with an FCC phase and a (Ni, Co)₃Ti phase emerged through annealing. In mechanics performance, the ultimate strength significantly increases from 1729 ± 15 MPa of the as-cast alloy to 2820 ± 15 MPa of the annealed alloy, while a relatively high hardness of 825.8 ± 16.3 HV and 680 ± 23.9 HV was obtained. It was suggested that the majority BCC phase and other precipitation both take the responsibility for the good synergy in strength and hardness.