Weldability and welding technology of high-entropy alloys: A review

High-entropy alloys (HEAs) have become essential materials in the aerospace and defense industries due to their remarkable mechanical properties, which include wear resistance, fatigue endurance, and corrosion resistance. The welding of high-entropy alloys is a cutting-edge field of study that is attracting a lot of interest and investigation from research organizations and businesses. Welding defects including porosity and cracks are challenging problem and limit the development of welding HEAs. This paper provides a comprehensive review of research on weldability of HEAs and the application of diverse welding techniques on welding HEAs over recent years. The forming mechanism and control strategies of defects during welding HEAs were provided in this work. Various welding techniques, including arc welding, laser welding, electron beam welding, friction stir welding, diffusion bonding and explosive welding, have been extensively investigated and applied to improve the microstructure and mechanical properties of HEAs joints. Furthermore, an in-depth review of the microstructure and mechanical properties of HEAs joints obtained by various welding methods is presented. This paper concludes with a discussion of the potential challenges associated with high-entropy alloy welding, thus providing valuable insights for future research efforts in this area.