A map of single-phase high-entropy alloys

TL;DR

This study uses high-throughput density-functional theory calculations to map and predict stable single-phase high-entropy alloys among over 650,000 combinations, identifying new alloys and revealing key factors influencing their formation.

Contribution

The paper presents the first large-scale chemical map of single-phase high-entropy alloys, predicting new stable alloys and elucidating the factors affecting their stability.

Findings

Identified over 30,000 potential single-phase high-entropy alloys.

Predicted and experimentally validated two new high-entropy alloys.

Unveiled the roles of mixing enthalpy, intermetallics, and melting point in alloy stability.

Abstract

High-entropy alloys have shown much interest and unusual materials properties. The stability of equimolar single-phase solid solution of five or more elements is likely to be rare and identifying the existence of such alloys has been very challenging because of the very large space of possible combinations. Herein, based on high-throughput density-functional theory calculations, we construct a chemical map of single-phase equimolar high entropy alloys by investigating over 650000 equimolar quinary alloys through a binary regular solid-solution model. We identify more than 30000 potential single-phase equimolar alloys (5% of the possible combinations) forming mainly in body-centered cubic structures. We unveil the chemistries that are likely to form high-entropy alloys, and identify the complex interplay among mixing enthalpy, intermetallics formation, and melting point that drives the formation of these solid solutions. We demonstrate the power of our method by predicting the existence of two new high entropy alloys, i.e. the body-centered cubic AlCoMnNiV and the face-centered cubic CoFeMnNiZn, which are successfully synthesized.