Study of atomic mobilities and diffusion characteristics in bcc Ti-Ta and Ta-W alloys

In order to assist the design of bcc Ti-Ta and Ta-W alloys, the atomic mobilities of Ti, Ta and W are studied critically with the DICTRA software (DIffusion Controlled TRAnsformation), based on the published thermodynamic description, self-diffusion coefficients, impurity diffusion coefficients, intrinsic diffusion coefficients and interdiffusion coefficients. Good agreement is obtained from the comprehensive comparisons between the calculated and measured diffusion coefficients. To further verify the obtained atomic mobilities, the concentration profiles and Kirkendall marker shift in bcc Ti-Ta and Ta-W diffusion couples are explored computationally, the results of which can reproduce satisfactorily the experimental measurements.