Fabrication, microstructure and properties of 10Ti-5Nb-1Sn biomedical β titanium alloy with low elastic modulus and high strength-ductility synergy

The new generation of β-type titanium alloy with low elastic modulus and high strength-ductility synergy has a good future in biomedical materials. In this paper, a 10Ti-5Nb-1Sn alloy was designed by D-electron theory and fabricated by vacuum arc melting. Then the effect of cold-rolling and heat treatment on the evolution of microstructure, tensile properties and elastic modulus of 10Ti-5Nb-1Sn alloy was systematically studied. The results have shown that the as-casted 10Ti-5Nb-1Sn ingot consists of single β phase, the tensile strength is 473MPa, the elongation is 35% and the elastic modulus is 36GPa. The cold-rolling could obviously enhance the tensile strength to 823MPa due to the high-density dislocation tangles and reduce the Young's modulus to 32GPa due to the formation of {001}<110> texture, but the elongation significantly decreased. After annealing, the 10Ti-5Nb-1Sn alloys could obtain a high strength-ductility synergy, i.e., tensile strength is 713MPa and elongation is 23%, and low elastic modulus (33GPa), which is close to human bone elastic modulus (10–30GPa) and has the potential to be used as metallic biomedical materials.