The migration of 64Cu in alloys which contained 2.14 or 6.48at%Al was studied, at temperatures ranging from 673 to 823K, by using sectioning methods. It was found that the grain boundary diffusivity in the 2.14at%Al alloy could be described by:

D (m3/s) = 8.5 x 10-13exp[-125(kJ/mol)/RT]

J.Cermak: Physica Status Solidi A, 1990, 121[1], K31-5