Experimental Investigations on the Interdiffusion Behaviors and Mechanical Properties of Ti-rich Ti-Mo-Zr System by Using the Diffusion Couple Technique

Accurate composition-dependent interdiffusion coefficients, modulus and hardness data are important for the design of biomedical Ti alloys. Three groups of body-centered cubic (bcc) Ti-Mo-Zr diffusion couples annealed at 1273 K for 7 d were experimentally prepared, and their composition gradients were determined by using the electron probe microanalysis (EPMA). The composition-dependent interdiffusion coefficients of Ti-Mo-Zr alloys were calculated by using a pragmatic numerical inverse method and Matano-Kirkaldy method. Subsequently, nanoindentation technique combined with the reverse analysis algorithms and Oliver-Pharr method was utilized to obtain the mechanical properties of the ternary diffusion couples. Finally, other property data including indirect wear resistance parameters, bulk modulus, and shear modulus were discussed. The composition-dependent mechanical property database of bcc Ti-Mo-Zr system can offer a guide for the design of Ti alloys.