Abstract: To address the limited wear resistance observed in traditional titanium alloys, we have developed an ultrafine-grained equiatomic TiMoNb compositionally complex alloy (CCA) with exceptional wear resistance. However, there is a significant lack of in vitro and in vivo evaluation of the TiMoNb CCA for biomedical applications. In this study, we comprehensively evaluate the corrosion behavior, tribo-corrosion performance, biocompatibility, and osseointegration of the TiMoNb alloy. Our findings indicate that the alloy exhibits strong corrosion resistance and stable tribo-corrosion behavior, attributed to the presence of Ti-rich nanoscale precipitates that impede tribo-corrosion-induced shear deformation, along with a protective nanoscale oxide layer. Furthermore, in vitro and in vivo evaluations demonstrate the excellent biocompatibility of the TiMoNb alloy and reveal its ability to promote the regeneration of defective femurs and its favorable bone osseointegration capability. Overall, our study underscores the potential of the TiMoNb alloy as a promising material for dental implants and provides valuable insights into the tribo-corrosion mechanisms of ultrafine-grained alloys.

Key words: TiMoNb, Tribo-corrosion, Biocompatibility, Osteointegration