Ni Grain Boundary Diffusion in Coarse-Grained Fe-40%Ni alloy and Comparison with Ni Diffusion in the Nanocrystalline Alloy

Abstract

Ni grain boundary (GB) diffusion in polycrystalline r-Fe-Ni alloy was measured by the conventional radio -tracer method. The double product P=d*D (d id the GB width and D is the GB diffusivity) was found to follow the Arrhenius relationship P=1.31*E-13*exp(-157kJmol/RT)m3/s, where Ris the gas constant and T is the temperature. The results in the coarse-grained material(grain size d~0.5 mm) werediscussed in comparison with our pervious investigation of Ni diffusion in a nanocrystalline alloy(d~100nm) of the dame composition.