The diffusion of Os in Ni is characterised by measuring interdiffusion coefficients in the binary Ni-Os system, in the temperature range 1200-1350°C. The results are compared with data for Ni-Re. Theoretical calculations indicate that Os should display a diffusion coefficient comparable with Re, among the lowest displayed by elements from the d-block transition elements. The authors' experimental findings confirm these predictions, and suggest that alloying with Os is likely to improve the high temperature properties of the nickel-based superalloys. © 2010 Institute of Materials, Minerals and Mining.
