Novel β-type Zr–Mo–Ti alloys for biological hard tissue replacements

•β-Type Zr–Mo–Ti alloys are developed based on biocompatible elements.•Ti element refines the microstructure.•Solid solution of Mo and Ti determines the mechanical properties.•Zr–12Mo–xTi alloys exhibit good combination of biomechanical properties.

In order to develop new biomaterials for hard tissue replacements, Zr–12Mo–xTi (x = 0, 3, 7 and 11, in at.%) alloys with required properties have been designed and prepared using vacuum arc melting method for the first time. Phase analysis and microstructural observation shows that all the as-cast samples consist of equiaxed β-Zr phase. Variations of lattice constants, volume and density of the Zr–12Mo–xTi alloys as a function of Ti content have been discussed. With the increase of Ti content, the microstructure is refined. The solid solution effect of the β-phase stabilization elements (i.e. Mo and Ti) predominantly determines the mechanical properties. These β-type Zr–12Mo–xTi alloys exhibit high compressive strength (1469–1584 MPa), high yield strength (1175–1375 MPa), high elastic energy (21–28 MJ/m3) and low Young’s modulus (32–35 GPa), together with plastic strain (11–25%). As the Zr–12Mo–xTi alloys are based on biocompatible elements, this good combination of biomechanical characteristics makes them potential biomedical materials for hard tissue replacements.