Diffusivities and Atomic Mobilities in fcc Cu-Ag-Al Alloys

By means of the solid-solid diffusion couples together with the electron probe microanalysis technique and Matano-Kirkaldy method, mole fraction interdiffusion coefficients in fcc Cu-Ag-Al alloys at 1073 K were measured. Based on the experimentally determined mole fraction interdiffusion coefficients as well as thermodynamic description of fcc phase, atomic mobilities of Ag, Al and Cu in fcc Cu-Ag-Al alloys were assessed by means of DIffusion-Controlled TRAnsformations software package. The calculated interdiffusivities based on the assessed atomic mobilities agree well with all the experimental data. The reliability of the presently obtained atomic mobilities was further verified by comprehensive comparisons between various model-predicted diffusion properties and the experimental data, including concentration profiles, interdiffusion fluxes and diffusion paths.