Silver tracer diffusion in oriented [formula omitted] interphase boundaries and correlation to the boundary structure

Abstract

Radiotracer experiments were performed on oriented AgCu bicrystals to study the influence of the interphase boundary (IB) structure on the material transport along the interfaces. Tracer diffusion of 110mAg was measured along (011) IBs in the [100] and [011̄] directions and along (111) IBs in the [011̄] and [2̄11] directions in the temperature range 593–882 K. It is demonstrated for cube-on-cube orientations how the interfacial structure is reflected in the diffusion behavior. It was found that the Ag diffusion along anisotropic misfit dislocation arrays in (011) IBs is anisotropic and fastest along channels of rapid diffusion. A scatter in the diffusion data for (011) IBs indicates that their structure, quite in contrast to morphologically stable (111) interfaces, depends on the thermal history of the specimens. This is interpreted as a result of microfaceting of the morphologically unstable (011) IBs. Furthermore, the influence of interdiffusion across the interface on the diffusion along the interface is discussed.