Diffusion in ', at between 1298 and 1573K, was studied by using the diffusion couple: Ni-24.2Al/Ni-24.4Al-2.91at%Co. The diffusion profiles were measured by using an electron probe micro-analyzer, and the diffusion coefficients of Co in ' which contained 24.2at%Al, were deduced from those diffusion profiles by using the Hall method. The temperature dependence of the diffusion coefficient was given by:

D(m2/s) = 0.0042 exp[-325(kJ/mol)/RT]

The Co atoms, which occupied the face-centered sites of the L12 structure, diffused according to the usual activation energy.

Y.Minamino, S.B.Jung, T.Yamane, K.Hirao.: Metallurgical Transactions, 1992, 23A[10], 2783-90