Simulation of Atomic Diffusion in the Fcc NiAl System: A Kinetic Monte Carlo Study

The atomic diffusion in fcc NiAl binary alloys was studied by kinetic Monte Carlo simulation. The environment dependent hopping barriers were computed using a pair interaction model whose parameters were fitted to relevant data derived from electronic structure calculations. Long time diffusivities were calculated and the effect of composition change on the tracer diffusion coefficients was analyzed. Our results indicate that this variation has noticeable impact on the atomic diffusivities. A clear reduction in the mobility of both Ni and Al is demonstrated with increasing Al content. Examination of the pair interaction between atoms was carried out for the purpose of understanding the predicted trends.