Carbon in copper and silver: diffusion and mechanical properties

The effects of interstitial carbon on the diffusion and mechanical properti es of copper and silver are studied theoretically. Semiempirical methodolog y, atomistic simulations, and first-principles density functional schemes a re combined to extract some understanding of the diffusion process and latt ice reconstruction in extremely dilute interstitial Cu-C and Ag-C alloys, l t is demonstrated that carbon inclusion in the host matrix leads to suffici ent non-uniform dilatation of the lattice. We also show that an account of static displacements is important in the calculations of the activation ene rgy for the diffusion of the interstitial atoms. The "embedded" cluster sch eme is suggested to simulate the relaxation in extremely dilute alloys. Hig h-resolution scanning electron microscopy results are presented, which demo nstrate the existence of a solid solution zone at the Cu-C interface. (C) 2 001 Elsevier Science B.V, All rights reserved.