Diffusion of titanium in copper

Interdiffusion coefficients in copper-titanium alloys have been determined by Matano's method in the temperature range between 973 and 1283 K on (pure Cu)-(Cu-1.98 at. pct Ti alloy) and (pure Cu)-(Cu-2.91 at. pct Ti alloy) couples. Temperature dependence of the impurity diffusion coefficient of titanium in copper, determined by extrapolation of the concentration dependence of the interdiffusion coefficient to zero mole fraction of titanium, is expressed by the following Arrhenius equation along with the probable errors:D _Ti/Cu=(0.693 _−0.135 ^+0.169 )×10⁻⁴exp−(196±2)kJ mol⁻¹/RT] m²/s. The difference in the activation energies for the impurity diffusion of the 3d-transition metals and self-diffusion in copper has been calculated by applying LeClaire's model with the oscillating potential of the impurity atom in copper. The calculated values agree well with the experimental values including the present one. Kazutomo Hoshino, formerly Graduate Student, Tohoku University