Interdiffusion and Diffusion Mobility for Fcc Ni-Co-Mo Alloys

Abstract

Ternary fcc Ni-Co-Mo diffusion couples annealed at 1273 and 1473 K have been scanned to measure composition profiles by using electron probe microanalysis. The interdiffusion coefficients were extracted using the Whittle–Green method from the measured composition profiles of the ternary diffusion couples. Based on the diffusion coefficients reported in the literature and data determined in the present work, the diffusion mobilities for fcc Ni-Co-Mo alloys were assessed. In addition, diffusion paths and composition profiles were simulated with presently assessed mobility parameters. In general, reasonable agreements have been reached and the resulted mobility database can be used to investigate the diffusion behavior of the ternary fcc Ni-Co-Mo alloys in wide composition and temperature ranges.