Brief introduction of high entropy alloy

Some people think that amorphous or glass atoms have high disorder or entropy, and high entropy will inevitably lead to high vitrification ability, so some people put forward chaos theory. But later, some scholars found that high entropy and high glass transition ability were not consistent, but found that some alloys with high mixed entropy could form single-phase solid solution. In this regard, Ye Junwei and others think that this solid solution is a stable solid solution with high mixing entropy, so it is named high entropy alloy. As for why the glass forming ability of high mixed entropy alloys is not high, Zhang Yong and others counted a large number of high mixed entropy alloys, systematically analyzed them from the perspectives of atomic size difference, mixing enthalpy and mixing entropy, and explained them with Adam-Gibbs equation.

It is found that high entropy alloys have some excellent properties that traditional alloys can't match, such as high strength, high hardness, high wear and corrosion resistance, high thermal resistance and high resistance. Therefore, it has become a new research hotspot in the fields of materials science and condensed matter physics. At present, the research of high entropy alloy mainly focuses on the performance test of as-cast alloy. We know that as-cast products have natural performance defects (such as cavities and pores caused by thermal expansion and cold contraction), but there are few reports on the properties after heat treatment and hot processing. It is predicted that in the next few decades, the three most promising research hotspots will be bulk amorphous, composite materials and high entropy alloys.