The migration of T in Al-1.1wt%Li, and in pure Al, was investigated by using a radiochemical method. It was found that most of the T which was incorporated into these materials existed in the T- state, and was released in the form of HT when the materials were heated in a vacuum. The T diffusivities which were determined from HT release measurements could be described by:

Al:     D (cm2/s) = 2.0 x 10-2exp[-53.4(kJ/mol)/RT]

Al-1.1wt%Li:     D (cm2/s) = 7.9 x 10-2exp[-72.4(kJ/mol)/RT]

The diffusivities for T in Al-1.1wt%Li were 1 or 2 orders of magnitude lower than those for Li in Al; depending upon the Li concentration. This was attributed to a trapping effect which was associated with the Li atoms in the material.

Tritium Diffusion and Trapping Associated with Lithium in Al-Li Systems. T.Hayashi, K.Okuno, H.Kudo, H.Amano: Journal of the Less-Common Metals, 1988, 141[1], 169-76