High entropy alloys prepared by spark plasma sintering: Mechanical and thermal properties
Chika Oliver Ujah, Daramy Vandi Von Kallon, Victor Sunday Aigbodion
Abstract
Conventional alloys and superalloys are useful in engineering, automotive, aerospace and medical applications. However, some are affected by high temperature oxidation while others lose strength at elevated temperatures. So, the quest to develop a material with high thermal stability, high strength at elevated temperature and high oxidation resistance, that high entropy alloys (HEAs) were invented. They are special type of alloys produced by consolidating multiple number of elements into a single entity. Their complexity, superior properties as well as their prospective wide range of applications provoked the zeal of researchers on the topic ever since their discovery for over two decades. This work, therefore, was aimed at taking a literature study on HEAs processed by spark plasma sintering (SPS). This was because SPS has been adjudged as one of the best processing techniques in powder metallurgy. The authors analyzed brief history of HEAs and SPS; mechanical, thermal and microstructural properties of HEAs; applications, challenges, and future work of HEAs. The study was concluded by observing that HEAs actually have high potential applications in aerospace, medical, military, and marine industries. However, more research needs to be done in order to maximize their usage.