Interdiffusion in Ni-Co-Re and Ni-Co-Ru Systems

Abstract

The diffusion in Ni-Co-Re and Ni-Co-Ru systems have been investigated in the temperature range 1323–1523 K through the determination of the interdiffusion coefficients. The main interdiffusion coefficients of these systems were larger than the cross interdiffusion coefficients, indicating that the influences of the own concentration gradients of the elements were generally still dominant. From the ratio of the cross interdiffusion coefficient to the main one, |\\ ildeD_ij^k⁄\\ ildeD_ii^k|, it was found that the effect of Co on the diffusion of Re was more appreciable than that of Ru. Moreover, by the comparison between the diffusion in the binary Ni-Re and in the ternary Ni-Co-Re, it was clear that the presence of Co reduced the Re diffusivity in Ni. The results of this work reflect two folds; the attractive force exists between Co and Re, and the interatomic bonding of Co-Re seems to be stronger than that of Ni-Re.