The migration of T in pure Al was investigated by using a radiochemical method. It was found that most of the T which was incorporated into the material existed in the T- state, and was released in the form of HT when the material was heated in a vacuum. The T diffusivities which were determined from HT release measurements could be described by:

D (cm2/s) = 0.020 exp[-53.4(kJ/mol)/RT]

T.Hayashi, K.Okuno, H.Kudo, H.Amano: Journal of the Less-Common Metals, 1988, 141[1], 169-76