New Advances in High-Entropy Alloys

Abstract

High-entropy alloys (HEAs) are alloys with high-entropy of configuration in the liquid state, this high-entropy intend to make the disordered phases stable, such as random solid solution or amorphous phases. The first generation of HEAs is defined as alloys with more than five components with an equiatomic ratio and single phase, which include face centered cubic (FCC), body centered cubic (BCC), hexagonal close packed (HCP), and amorphous structured HEAs. The recent advances in HEAs mainly focus on the second generation of HEAs, e.g., the non-equiatomic ratio and dual phase HEAs, which include four kinds of HEAs: (1) eutectic HEAs, which have excellent casting properties; (2) precipitation hardening HEAs, which is potentially the next generation of superalloys; (3) phase transformation induced plasticity (TRIP) HEAs; and (4) ultrafine grain HEAs. HEAs potentially break the property limits of the traditional alloys.