The activity of Cu in solid α-Co was determined at 1158 to 1473K by equilibrating Co plates against molten Ag-Cu alloys. The equilibrated plates were essentially binary Co-Cu alloys. The interdiffusivities in the latter alloys were determined from the penetration profiles at 1158 to 1273K. It was found that the results could be described by:

D (cm2/s) = 1.0 x 100 exp[-65.5(kcal/mol)/RT]

M.Arita, M.Nakamura, K.S.Goto, Y.Ichinose: Transactions of the Japan Institute of Metals, 1984, 25[10], 703-9