Assessment of the atomic mobility for the fcc phase of Ni–Co–X (X=Re and Ru) system

• The atomic mobility for the fcc phase of Ni–Ru binary system and Ni–Co–Re and Ni–Co–Ru ternary systems have been assessed using the DICTRA software.
• The thermodynamic descriptions for the Co–Re and Co–Ru systems were assessed in this work.
• The mobility parameters of the Ni–Co–Re and Ni–Co–Ru ternary systems were obtained.
• An agreement between the calculated results and experimental diffusion data was obtained.
• The assessed atomic mobilities were further validated by the evaluation of concentration profiles and diffusion paths in several diffusion couples.

The thermodynamic parameters of Co–Re and Co–Ru systems were assessed using the CALPHAD technique. Based on various experimentally measured diffusivities and the thermodynamic parameters, the atomic mobility for the fcc phase of Ni–Co–X (X=Re, Ru) system was assessed using the DICTRA software. Comprehensive comparisons between calculated and experimental diffusion coefficients showed that the experimental data could be well reproduced by the atomic mobilities obtained in the present work. The developed diffusion mobilities were further validated by the prediction of some diffusion behavior, especially the concentration profiles and diffusion paths in diffusion couples.