Eutectic High-Entropy Alloys

Eutectic high-entropy alloys (EHEAs), as a subclass of high-entropy alloys (HEAs), exhibit various excellent mechanical, physical, and anti-corrosion properties as well as excellent castability, which are becoming one of the research frontiers in the metal alloy field. EHEAs combine nicely the unique advantages of eutectic alloys and HEAs, with in-situ formed composite structure containing multi-principal components during the solidification process. Since the first report of EHEAs in 2014, plenty of investigations have been made on the topic, resulting in dozens of promising candidate EHEAs for future applications. In this chapter, the recent research advances in EHEAs were summarized, to comprehensively present the historical development, current situation, and future aspects of EHEAs. The concept of EHEAs was firstly introduced, which was proposed based on the special solidification microstructure of eutectic alloys. The excellent mechanical performance in directly cast EHEAs inspired rapid developments on this topic. Then, several alloy design methods were introduced, for the efficient prediction of new EHEA systems. Meanwhile, the deformation behavior and mechanisms have been thoroughly investigated for a mechanistic understanding of the superior mechanical properties of EHEAs, and they were summarized here. Finally, the potential applications and future developments of EHEAs were suggested as a concluding remark.