Mobilities, interdiffusivities and their kinetic implications for fcc Ni-Al-Nb alloys

To explore diffusion behavior of fcc phase in the Ni-Al-Nb ternary system, binary and ternary alloys were prepared by induction melting to make diffusion couples which were annealed at 1473 K for 50 h. The interdiffusion coefficients were evaluated from the common compositions of two independent diffusion paths, which were then combined with the thermodynamic description to inversely determine the atomic mobilities of Ni, Al and Nb in DICTRA. Comparations between calculated and experimentally-measured interdiffusivities and diffusion profiles in diffusion couples were made, the results of which demonstrate the quality of atomic mobilities obtained in this work.