Progress in High-Entropy Alloy Performance Enhancement

Abstract

High-entropy alloy (HEA) is currently regarded as materials with the most superior comprehensive properties, possessing capabilities not found in traditional alloys. This is particularly attributed to the characteristic presence of multiple principal elements, endowing the alloys with exceptional performance across various aspects, thus becoming a focal point of both current and future research endeavors. The performance of HEA is derived from phase transition. This review summarizes the intrinsic phase transition of HEA itself and the enhancement of HEA performance through the addition of particulate phases. Starting from the definition of HEA, the common definitions are introduced, leading to the design principles of HEA and the prediction of solid solution phases. The influence of different elements on the structural changes of HEA solid solution phases is explained through lattice distortion phase transition and segregation phase transition methods. The patterns of phase transition induced by large atomic elements are summarized, and the development process of segregation phase transition by small atomic elements is presented, offering references for future research on HEA. Furthermore, the concept of solubility of elements in HEA is introduced, based on the phase transition caused by large and small atomic elements, providing a more accurate basis for the design and preparation of HEA. The common hard particles used to enhance the performance of HEA are discussed, revealing how direct addition of particles can lead to decomposition and the uncertainty of the effects of elements on HEA performance. The significance of encapsulation techniques in enhancing the performance of high-quality HEA is proposed.