Diffusion of copper, silver and gold in α-titanium

Abstract

The diffusion coefficients of Ib metals (Cu, Ag and Au) in α-Ti have been determined in the temperature range 980–1120 K by extrapolating the concentration dependence of the interdiffusion coefficients to infinite dilution of the binary α-Ti solid-solutions. The diffusivity of Cu shows fast impurity diffusion in α-Ti, while Ag and Au behave as normal diffusers. For normal diffusion in α-Ti a linear relationship between the logarithm of the pre-exponential factor and the activation energy has been observed, while the plots for the fast diffusers are located far above the line for the normal diffusers. This suggests that fast diffusion can be characterized by a large pre-exponential factor.