Microstructure evolution and mechanical properties of a Ti-35Nb-3Zr-2Ta biomedical alloy processed by equal channel angular pressing (ECAP).

In this paper, an equal channel angular pressing method is employed to refine grains and enhance mechanical properties of a new β Ti-35Nb-3Zr-2Ta biomedical alloy. After the 4th pass, the ultrafine equiaxed grains of approximately 300 nm and 600 nm are obtained at pressing temperatures of 500 and 600°C respectively. The SEM images of billets pressed at 500°C reveal the evolution of shear bands and finally at the 4th pass intersectant networks of shear bands, involving initial band propagation and new band broadening, are formed with the purpose of accommodating large plastic strain.