Ni and Ga diffusion in polycrystalline Ni 3Ga

Abstract

The volume and grain boundary (GB) diffusion of 63Ni and 67Ga radiotracers in polycrystals of Ni 3Ga intermetallic was studied in the vicinity of the stoichiometric composition A 3B (23.5–28.3 at.% Ga). Both volume and GB diffusivity was investigated in the temperature interval 773–1373 K by the residual activity method. The obtained Ga volume diffusivity increases with increasing Ga concentration x Ga; the increasing tendency of Ni volume diffusivity with increasing x Ga is pronounced at lower temperatures. GB diffusivity of both Ga and Ni in Ni 3Ga are close one to another and—contrary to the diffusion behavior of components in Ni 3Al—they do not show any significant dependence on x Ga.