Development of atomic mobility with quantified uncertainties directly from concentration profiles: a demo in fcc Cu–Ni–Sn system

This work delivers a report on development of atomic mobility description with quantified uncertainties directly from concentration profiles via the Markov chain Monte Carlo algorithm as implemented in HitDIC software, which was demonstrated in fcc Cu–Ni–Sn ternary system. Different from the traditional mobility evaluation, the present new strategy started from the collection and review of all the concentration profiles available in the literature. Based on the collected concentration profiles, the atomic mobility descriptions and the corresponding quantified uncertainties in fcc Cu–Ni–Sn ternary and its sub-binary systems were directly evaluated. The reliability of the obtained mobility descriptions was firstly validated by the good agreement between the simulated and measured composition profiles, as well as by the calculated and reported inter-, tracer and intrinsic diffusivities. The fit of diffusion quantities to the experimental results as predicted by the present mobilities was also found to be generally better than previous traditional assessments, further verifying the accuracy of the present mobility descriptions. Moreover, the estimated mobility uncertainties suggest that the stability and reliability of mobility descriptions highly depend on the quantity and quality of the input concentration profiles. The successful demonstration of the present work indicates that the high-quality atomic mobility database in various alloys can be efficiently established by combining the HitDIC software and reliable concentration profiles.