Atomic mobilities, interdiffusivities and their related diffusional behaviors in fcc Co-Cr-Ni alloys

Diffusion couples for fcc Co-Cr-Ni ternary system are prepared, all of which are annealed at 1573 K for 50 h. Interdiffusion coefficients are evaluated at the intersection points of two independent diffusion paths sharing a common composition. Such main and cross interdiffusion coefficients are then used to inversely retrieve atomic mobilities of Co, Cr and Ni in fcc Co-Cr-Ni alloys, with the aid of available thermodynamic description. Further validation concerning the quality of atomic mobilities is conducted with computational simulations for diffusion couples annealed at 1573 K for 50 h, the results of which are compared with experimental data. This work contributes to the establishment of a general Co- or Ni-based kinetic database for computational design of superalloys.