Investigation of diffusivities and mechanical properties in BCC Ti rich Ti-Zr-Ta system

In this work, a combination of diffusion couple technique and nanoindentation were employed to investigate the diffusion behaviors and mechanical properties of Ti-Zr-Ta alloys annealed at 1373 K for 26 h. The experiments focused on Ti-rich body-centered cubic (BCC) Ti-Zr-Ta ternary alloys. Diffusion coefficients were determined using the Whittle-Green and generalized Hall methods, while nanoindentation was utilized to characterize Young's modulus and hardness of the alloys. The results indicate that the diffusion rate of Zr is considerably higher than that of Ta, and the diffusion rate of both elements exhibits a strong dependence on concentration. The mechanical testing results demonstrate a significant increase in the hardness and Young's modulus of the alloy as the Ta content increases. In contrast, the Zr content shows a relatively limited effect on hardness and Young's modulus. These results provide an essential reference for further optimization of the microstructure and mechanical properties of Ti-Zr-Ta alloys at elevated temperatures.