Interdiffusion and Atomic Mobility Studies in Ni-Rich fcc Ni-Co-Al Alloys

The ternary interdiffusion coefficients in fcc Ni-Co-Al alloys at 1373 K were determined using Whittle and Green method together with electronic-probe microanalysis. With the help of DICTRA software, the experimental diffusion coefficients were critically assessed to obtain the atomic mobilities of Ni, Co and Al in fcc Ni-Co-Al alloys. Comprehensive comparisons between calculated and experimental diffusion coefficients showed that the experimental data could be well reproduced by the atomic mobilities obtained in the present work. The developed diffusion mobilities were further validated by the calculation of the concentration profiles and diffusion paths in diffusion couples.