Diffusion and segregation of silver in copper Σ5(310) grain boundary

Abstract

Grain boundary diffusion of 110mAg in Cu Σ5(310) bicrystal is measured along and perpendicular to the [001] tilt axis in both C and B kinetic regimes after the common Harrison's classification. The grain boundary diffusion coefficients, D gb, of the single grain boundary in a true dilute limit of solute concentration are determined in the C kinetic regime and the values of the triple products P=s•δ•D gb are measured in the B regime (here s and δ are the segregation factor and the diffusional grain boundary width, respectively). A strong anisotropy of the grain boundary diffusion is established, which disappears above 826 K. It is the point at which the triple product P demonstrates a downward deviation from the otherwise linear Arrhenius dependence at lower temperatures. These results substantiate a temperature-induced disordering transition of the grain boundary structure. The anisotropy of the product s•δ for the Σ5(310) grain boundary is estimated. © 2012 American Physical Society.