The diffusion of Cu, Fe, and Si in Ni-24.9at% was studied at 1373 to 1573K by using diffusion couples (figure 10). It was found that the temperature dependences of the diffusion coefficients could be described by:

Cu:     D(m2/s) = 1.28 x 10-2exp[-331(kJ/mol)/RT]

Fe:     D(m2/s) = 1.28 x 10-2exp[-335(kJ/mol)/RT]

Si:     D(m2/s) = 8.51 x 10-2exp[-363(kJ/mol)/RT]

The activation energies were found to be closely related to the substitution behavior of Cu, Fe and Si atoms in the L12 lattice sites of '.

Diffusion of Copper, Iron and Silicon in Ni3Al. Jung, S.B., Minamino, Y., Araki, H., Yamane, T., Hirao, K., Saji, S.: Defect and Diffusion Forum, 1993, 95-98, 859-64

Table 13

Bulk diffusivity of 67Ga in Ni3Al