On the basis of the available thermodynamic parameters, the atomic mobilities ofNb and Zr in body-centred cubic Nb–Zr alloys were critically assessed as functions of temperature and composition by using the CALPHAD method, where self-diffusion coefficients, impurity diffusion coefficients, tracer diffusion coefficients, interdiffusion coefficients and concentration curves were simultaneously optimized. Comparisons between the calculated and experimentally measured diffusion coefficients were made, where good agreement was evident. In addition, the obtained mobility parameters could reproduce a reasonable concentration profile for the Nb/Zr diffusion couple annealed at 1868K for 5400s.

Study of Diffusion Mobilities of Nb and Zr in BCC Nb–Zr Alloys. Y.Liu, L.Zhang, T.Pan, D.Yu, Y.Ge: Calphad, 2008, 32[3], 455-61