Research progress on impact deformation behavior of high-entropy alloys

Abstract

As a kind of multi-principal component alloy, high-entropy alloy breaks through the design idea of traditional single-principal component alloys, and shows excellent properties different from traditional alloy. It has a good application prospect in extreme environments including high temperature, high pressure and high strain rate. Analyzing the impact deformation characteristics of high entropy alloy from micro, meso and macro scale is of great importance for its engineering application, which includes the influences of the element effect, macrostructure and high temperature and high strain rate conditions on the impact damage evolution, microstructure change and impact deformation evolution process of high entropy alloys. In terms of the effect of elements on the mechanical properties of high entropy alloys, the effect of the great difference between the atomic radius of metal and nonmetal elements on the impact deformation is mainly discussed. According to the micro scale structure, the high entropy microstructure of single-phase alloy can be divided into face centered cubic (FCC) structure with better plasticity and body centered cubic (BCC) and hexagonal close-packed (HCP) structure with higher strength. The microstructure of multiphase high entropy alloy is the combination of these three single-phase structures and other phases. The cooperative deformation of multiphase high entropy alloy ensures it to obtain more excellent comprehensive mechanical properties. High temperature and high strain rate as external conditions exhibit similar effect on the high-entropy alloy and other metals. High temperature promotes material softening, while the high strain rate promotes material hardening. Some high entropy alloys have better mechanical properties at high temperature. According to the impact characteristics of high-entropy alloy, the applications of high-entropy alloy in the field of national defense engineering impact are summarized. The existing problems in the research of impact deformation behavior of high-entropy alloy are analyzed, and the applications of high-entropy alloy in extreme conditions are prospected.