The diffusion of Ta in the hexagonal close-packed phase of 4N Ti was studied at 911 to 1123K. Rutherford back-scattering spectrometry and heavy-ion Rutherford back-scattering techniques were used to obtain the penetration profiles. The diffusion coefficient obeyed the Arrhenius law, with an activation energy for diffusion of 318kJ/mol. This was similar to that corresponding to self-diffusion in hexagonal close-packed Ti. On the other hand, the measured values of the diffusion coefficient were systematically lower, than those corresponding to self-diffusion, by a factor of about 5. This reduction could be explained by taking account of the mass difference between Ta and Ti. An increase in the diffusion coefficient was measured when diffusion occurred in a 3N Ti matrix. This increment was higher at lower temperatures.

Diffusion of Ta in Ti. R.A.Pérez, F.Dyment, G.G.Bermúdez, D.Abriola, M.Behar: Applied Physics A, 2003, 76[2], 247-50