Additive manufacturing of compositionally complex alloys: Trends, challenges, and future perspectives

The recent decade has witnessed the evolution of a novel alloying paradigm based on using multiple elements to design compositionally complex alloys also known as high entropy alloys (HEAs). Conventional manufacturing of HEAs has a number of drawbacks, especially in terms of mechanical properties and design complexities. This has been addressed by additive manufacturing (AM), which has not only led to the fabrication of complex-shaped HEA components but has also enabled both ex situ and in situ control of alloy microstructures. In view of the recent developments in AM-based fabrication of HEAs, the present status and challenges in the avenue of AM of HEAs have been highlighted in the present chapter with special emphasis on the recent trends in the avenue of AM-based fabrication of HEAs from the viewpoints of (i) microstructure evolution and mechanical properties and (ii) alloy fabrication techniques.