The diffusion of implanted Pd in α-Ti was studied, at 723 to 1073K, by using Rutherford back-scattering and channelling techniques (table 246). The measurements showed that the diffusion data (figure 39) could be described by:

D (m2/s) = 2.0 x 10-3 exp[-264(kJ/mol)/RT]

Channelling experiments which were performed at 673 to 973K showed that, regardless of the annealing temperature, at least 30% of the Pd atoms were located in interstitial sites of the Ti matrix. A comparison with published data indicated that Pd diffused more rapidly than did substitutional elements, but more slowly than did interstitial elements (Fe, Co, Mn). This suggested that the diffusion mechanism was not purely substitutional, but had a mixed character.

M.Behar, M.R.F.Soares, F.Dyment, R.A.Pérez, S.Balart: Philosophical Magazine A, 2000, 80[6], 1319-34

Table 246

Diffusivity of Pd in α-Ti