Diffusion coefficients of oxygen in directions parallel to the c-axis (Dc) and a-axis (Da) of Ti3Al single crystals were measured via oxygen implantation and Auger electron spectroscopy. The diffusion coefficients were three orders of magnitude lower than those in α-Ti. The value of Dc/Da was 0.94 to 1.11, and the diffusion anisotropy was weak; despite the anisotropic arrangement of octahedral sites. The diffusion mechanism was considered in terms of the ordered arrangement of two types of octahedral sites occupied by oxygen atoms.

Oxygen Diffusion in Ti3Al Single Crystals. Y.Koizumi, M.Kishimoto, Y.Minamino, H.Nakajima: Philosophical Magazine, 2008, 88[24], 2991-3010