Interdiffusion experiments were performed on Ni3Al by using single-phase diffusion couples at 1273 to 1473K. The interdiffusion coefficient was larger, than the self-diffusion coefficient of Ni, by about an order of magnitude and increased with increasing Al concentration. At the stoichiometric composition, the apparent activation energy and the pre-exponential factor for interdiffusion were 243kJ/mol and 10-4.9m2/s, respectively (table 2). An attempt was made to estimate the self-diffusion coefficient of Al on the basis of the Darken-Manning equation.

Interdiffusion in Ni3Al. Ikeda, T., Almazouzi, A., Numakura, H., Koiwa, M., Sprengel, W., Nakajima, H.: Defect and Diffusion Forum, 1997, 143-147, 275-8

Table 2

Arrhenius parameters for interdiffusion in Ni3Al

Figure 1

Diffusion of Al and Nb in a Ni75.5Al24.5/Ni77.5Al15.0Nb7.5 couple

White circles, i = Nb; black circles, i = Al