| Abstract Scope |
We investigate the claims (see, for example, W. Yeh, et al., Adv. Eng. Mater., 2004) that increasing the number of constituents in compositionally complex random alloys causes diffusion to be sluggish. Our theoretical calculations of vacancy-assissisted diffusion in the 57 random, equimolar alloys that can be formed from Cu, Ag, Au, Ni, Pd, and Pt are based on the well-tested Embedded Atom Method functions of Foiles, Baskes, & Daw (S.M. Foiles, M.I. Baskes, and M.S. Daw, Phys. Rev. B 1986). We find that only a small minority of the alloys exhibit “sluggish” diffusion whereas in the large majority of alloys diffusion is faster and in quite a few cases could be considered “vigorous”. We find that the diffusivity does not correlate with the number of constituents but does correlate very well with the constituent diffusivities and lattice mismatch. |