Properties and processing technologies of high-entropy alloys

High-entropy alloys (HEAs) are emerging materials that are developed based on entropy, and draw significant attention for the potential to design their chemical disorder to bring out different structural and physical characteristics. Over the past two decades, significant salient efforts have been conducted to explore many unique and useful properties of HEAs, such as overcoming the strength-ductility trade-off, outstanding thermal stability, and excellent low temperature plasticity. Here, we review the key research topic of HEAs in the following three aspects: (a) performance advantages and composition design, (b) performance-driven HEAs and (c) fabrication process-driven HEAs. Towards their industrial applications, our article reviews a large range of methods to synthesise, fabricate and process HEAs. We also discuss the current challenges and future opportunities, mainly focusing on performance breakthroughs in HEAs.