Kinetic modeling of diffusion mobilities in bcc Ti-Nb alloys

Based on the thermodynamic parameters and various experimental diffusion data available in the literature, the atomic mobilities of Ti and Nb in bcc Ti-Nb alloys are critically evaluated with respect to temperatures and compositions in terms of the CALPHAD method. The finally obtained mobility parameters are presented, and extensive comparisons between the calculated and experimentally measured quantities are made. The results show that the obtained mobility parameters can satisfactorily reproduce most of the experimental results, and therefore they can be safely used in diffusion-related simulations to deal with practical problems of interest. In addition, the obtained mobilities, together with the published thermodynamic information, are successfully applied to model the movement of Kirkendall markers in the Ti/Nb diffusion couples.