Interdiffusion and Atomic Mobilities in fcc Ni-Mo-Ta Alloys

Ternary fcc Ni-Mo-Ta diffusion couples annealed at 1473 and 1573 K have been studied by using electron probe microanalysis. Based on the measured concentration-distance profiles and Whittle–Green method, the interdiffusion coefficients were calculated to critically assess the atomic mobilities by means of DICTRA software package. Comprehensive comparisons between calculated and experimental diffusion coefficients show that the atomic mobilities obtained in this work could well reproduce the experimental data. Reasonable agreements between model-predicted diffusion properties and the experimental data indicated that present mobility database can be used to study the diffusion behavior, such as diffusion paths and concentration-distance profiles in the ternary fcc Ni-Mo-Ta alloys.