The diffusion of Fe was measured by using radiotracers and precision grinding. It was found that Fe exhibited fast-diffusion behavior, in that its diffusivity was 2 orders of magnitude higher than that of Ti. The diffusion data could be described by:

D (m2/s) = 1.96 x 10-3 exp[-277.2(kJ/mol)/RT]

J.Breuer, T.Wilger, M.Friesel, C.Herzig: Intermetallics, 1999, 7[3-4], 381-8