An investigation was made of the effect of the Fe content upon Fe diffusion in the -phase (table 300). The pre-exponential factors and activation energies which were obtained for polycrystalline Ti-334ppm[wt]Fe samples were found to lie between the equivalent values for diffusion parallel to, and perpendicular to, the c-axes of Ti monocrystals. It was therefore concluded that the addition of Fe did not affect Fe diffusion in the studied temperature range. However, at temperatures below 822K, there were appreciable deviations from the Arrhenius plot. Thus, the diffusivity at 795K was lower (than that extrapolated from higher temperatures) by a factor of 4. The suppression of Fe diffusion was attributed to the formation of Fe complexes, or to the precipitation of TiFe, at temperatures below 822K.

H.Nakajima, K.Yusa, Y.Kondo: Scripta Materialia, 1996, 34[2], 249-53