Diffusion coefficients for modeling the heat treatment of Ti-6Al-4V

Values of the diffusivity of aluminum and vanadium that can be used for engineering-oriented calculations of the diffusional growth of primary alpha during the heat treatment of Ti-6Al-4V were established using diffusion couples consisting of various Ti-Al-V alloys. After taking compositional influences into account using thermodynamic correction factors, the pertinent diffusivities in the ternary alloy were found to be approximately 80 pct of those previously estimated from tracer or impurity (binary) diffusion experiments. This work was conducted as part of the in-house research of the Metals Processing Group of the Air Force Research Laboratory’s Materials and Manufacturing Directorate.