Review ® Research and Development of Titanium-Containing Biomedical High Entropy Alloys (BioHEAs) Utilizing Rapid Solidification via Laser-Powder Bed Fusion+1

Abstract

High entropy alloys (HEAs) have been developed as a new class of structural materials that consist of multicomponent elements with an approximately equiatomic ratio for increasing the mixing entropy to stabilize the solid solution phase. HEA for biomedical applications (BioHEA) was first developed in Japan; HEA comprising nonbiotoxic elements was specifically designed, demonstrating excellent mechanical properties and biocompatibility. However, elemental segregation, often observed in BioHEAs, hinders the inherent functions derived from high entropy effects and solid solution hardening. In this review article, elemental homogenization and functionalization of BioHEAs utilized by ultra-rapid cooling via laser-powder bed fusion and the characteristics of these BioHEAs, especially focusing on their excellent properties for biomedical applications, are introduced. [doi:10.2320/matertrans.MT-MLA2022011]