The tracer grain-boundary diffusivity of Ni in polycrystalline Ni-B, Ni-9at%Al-B and in a NiAl-B intermetallic was measured for B concentrations of up to 0.3at%. The measurements were performed using the residual activity method at temperatures ranging from 773 to 1073K. It was observed that the grain-boundary diffusivity decreased with increasing B concentration, in Ni-B and Ni-9at%Al-B. This behavior was similar to the dependence of grain-boundary diffusivity upon B content in Ni3Al, which had already been reported. However, in the case of B-doped NiAl, the grain-boundary diffusivity did not depend upon the B content.

Short-Circuit Diffusion in Ni-Al Alloys. J.Cermak, I.Stloukal, J.Ruzickova, A.Pokorna: Intermetallics, 1998, 6[1], 21-8