Diffusion in FCC Co-rich Co-Al-W Alloys at 900 and 1000 °C

Diffusion couple experiments between various Co-rich face centered cubic (FCC) alloys in the Co-W-Al ternary system have been conducted at 900 and 1000 °C. Diffusion coefficients have been extracted for the Co-W binary and for ternary alloys at compositions where the diffusion paths cross. In addition, a least squares method has been utilized to optimize diffusion mobility parameters using DICTRA simulations to best fit the experimental concentration versus distance curves. Predictions of the diffusion matrix using the refined mobility database are in good agreement with the values obtained at the diffusion path crossing points.