Influence of Palladium on Diffusion Processes in the B2 NiAl Phase

摘要

The study of diffusion couples made with ternary beta (Ni_(1-x)Pd_x)_(1+y)Al_(1+y) aluminides highlights the effect of Pd on diffusion processes in the Pd modified B2 NiAl phase. In the stoichiometric aluminide phase, alloying of beta-NiAl with Pd induces an increase of D_(Ni) and D_(Pd) with Pd content. In the sub-stoichiometric aluminide phase, if Pd and Ni gradients have an opposite sign, Pd significantly slows down Ni diffusion. Inversely, if Pd and Al gradients have an opposite sign, the influence of Pd on Al diffusion is quite low.