During heat-treatment at temperatures of up to 1000C in vacuum, a loss of Al was observed. It was noted that the rate of this out-gassing was governed by the diffusion of Al from the metal to the vacuum. It was shown that the concentration profile of Al below the heat-treated surface fitted a diffusion process. The diffusion coefficient which was deduced from this was found to compare well with published data.

L.Buisson, P.Bracconi: Journal of Nuclear Materials, 1996, 228[2], 257-9