Development of non-equiatomic Ti-Nb-Ta-Zr-Mo high-entropy alloys for metallic biomaterials

Abstract Nobel non-equiatomic Ti-Nb-Ta-Zr-Mo high-entropy alloys (HEAs) for metallic biomaterials (bio-HEAs) were designed and developed. The pseudo-binary phase diagrams focusing on solidification were constructed by thermodynamic calculations. The shifting the alloy composition of the equiatomic TiNbTaZrMo bio-HEA can realize the drastic improvement of the deformability. Notably, the non-equiatomic Ti, Zr-rich composition stimulated the molecular interaction between biological cells and bio-HEA, indicating the possibility of the proposed non-equiatomic Ti-Nb-Ta-Zr-Mo HEAs as an advanced biomaterial for bone tissue engineering applications. This is the first achievement for the alloy design including the control of alloy composition for the development of new bio-HEAs.