Phase boundary migration, Kirkendall marker shift and atomic mobilities in fcc Au–Pt alloys

The CALPHAD technique has been utilized to study the diffusion characteristics and atomic mobilities in fcc Au–Pt alloys, where the thermodynamics and kinetics descriptions are concurrently taken into consideration. For the investigated atomic mobilities, the end-members and interaction parameters are explored with the impurity diffusion coefficients, intrinsic diffusion coefficients and interdiffusion coefficients. Concentration curves in diffusion couples are computationally studied, the results of which are compared with the experimental values. In addition, the shift and distribution of Kirkendall markers are brought into discussion, based on the intrinsic diffusivities described in the lattice-fixed frame of reference.

► The atomic mobilities of Au and Pt in fcc Au–Pt alloys have been reported. ► The diffusion characteristics for intrinsic diffusion and interdiffusion have been explored. ► The kinetics of sharp phase interface and Kirkendall markers have been investigated. ► This work contributes to the establishment of an Au-based mobility database.