High-throughput exploration of composition-dependent mechanical and diffusion properties of Ti-Al-V-Cr alloys

This study investigates the diffusion and mechanical properties of Ti-Al-V-Cr alloys to facilitate high-strength titanium alloys design. In this study, ten solid/solid diffusion couples were prepared using body-centered cubic (BCC) Ti-Al-V alloys and annealed at 1373 K and 1473 K for 8 hours. The atomic mobility parameters for the Ti-Al and Al-V binary systems were re-optimized, the diffusion coefficients of the Ti-Al-V system were calculated, and an atomic mobility database for the Ti-Al-V system was established. Six sets of quaternary solid/ solid diffusion couples were annealed at 1373 K for 7 hours. A comprehensive atomic mobility database for the Ti-Al-V-Cr system was developed using the CALculation of PHAse Diagrams (CALPHAD) method. Numerical inverse determination of diffusion coefficients for BCC Ti-Al-V-Cr alloys at 1373 K. Nanoindentation and Electron probe microanalysis (EPMA) measurements were employed to systematically investigate the variation of Young's modulus, hardness, and elastic recovery as functions of alloy composition along the diffusion interfaces. Consequently, a composition-dependent mechanical property database for Ti-rich Ti-Al-V-Cr alloys was developed. Additionally, wear resistance and hot service parameter of the alloys were evaluated. Among the studied compositions, the Ti-5Al-0.5V-11.1Cr (TAVC) alloy exhibited superior hardness-to-Young's modulus ratios (H/E and H3/E2), excellent wear resistance, and favorable hot service parameters. These findings provide valuable insights into the design and optimization of Ti-Al-V-Cr alloys for high-strength applications, elucidating the intricate relationships between alloy composition and mechanical performance.