Microstructure and Young's Modulus of (TiZr)2-x(NbTaMo)x Bio-High Entropy Alloys

In recent years, high-entropy alloys (HEAs) have attracted significant attention owing to their remarkable physical properties such as high strength. It has also been reported that HEAs have a high potential as biomaterials. Bcc-type bio-HEAs possess high strength and biocompatibility equivalent to those of pure titanium. Bio-metallic materials require a low Young's modulus, similar to that of natural bone, but the Young's modulus of bio-high entropy alloys has not yet been clarified. Therefore, this study elucidates the relationship between microstructure control and Young's modulus in titanium-based bio-HEAs. The TiNbTaZrMo-based bio-HEAs were composed of two bcc phases. These two phases correspond to dendrite and interdendrite structures, respectively. In this study, it was found that by varying the volume fractions of these two phases, it is possible to control the Young's modulus.