Effect of CaB6 addition on the microstructure and mechanical properties of Ti-24Nb-4Zr-2.5Mn alloys fabricated by spark plasma sintering

Balancing the strength, ductility and Elastic modulus of beta-Ti alloys is still a great challenge for medical implantation, extremely limiting its further applications. Herein, we prepared a fine-grain beta-type Ti-24Nb-4Zr2.5Mn alloy with high performance by adding CaB 6 deoxidizer via mechanical alloying and spark plasma sintering. The effects of CaB 6 addition on the microstructure and mechanical properties were systematically investigated, and the results show that adding a trace amount of CaB 6 will form in -situ nano -sized CaTiO 3 particles and micro -sized (Ti,Nb)B 2 solid solution whiskers, which can significantly refine the grain size and inhibit the grain boundary movement and dislocation motion, thus improving the comprehensive mechanical properties of Ti-24Nb-4Zr-2.5Mn alloys. With a trace addition of 0.1 wt% CaB 6 , the Ti-24Nb-4Zr-2.5Mn alloy exhibits an excellent combination of high strength of -971 MPa, good ductility of -17.8% and low elastic modulus of -79.1 GPa. This work may provide a new methodology to prepare high-performance biomedical Ti alloys.