Diffusivities and Atomic Mobilities for the Cu-Rich fcc Cu-Al-Sn Alloys at 1073 K

Utilizing the solid–solid diffusion couples with the electron probe microanalysis technique, the composition-dependent ternary interdiffusion coefficients in fcc Al-Cu-Sn alloys at 1073 K were determined via the Whittle and Green method. Based on the experimentally determined interdiffusion coefficients at 1073 K combined with thermodynamic descriptions of fcc phase, atomic mobilities of Al, Cu, and Sn in fcc Al-Cu-Sn alloys were assessed by using CALTPP (Calculation of thermophysical properties) software. The quality of the assessed kinetic characteristics was confirmed by the comprehensive comparisons between various model-predicted diffusion behaviors and the experimental ones, including concentration profiles and diffusion paths.