Diffusion in Cu(AI) solid solution

The solid state diffusion characteristics in the Cu(Al) solid solution phase, was investigated in the temperature range of 1023-1223 K using single phase bulk diffusion couples between pure Cu/Cu- 10 at.% Al. The interdiffusion coefficients, D, were calculated using Boltzmann-Matano method and Hall's method from the concentration profiles of the couples that were determined using EPMA. The interdiffusion coefficients (D) calculated ranges between 1.39 × 10-14 and 3.97 × 10-13 m2/s in the temperature range of 1023 to 1223 K. The composition and temperature dependence of D were established. The activation energy for interdiffusion varies from 123.1 to 134.2 kJ/mol in the concentration range 1 at. % ≤ CAl ≤ 9 at. %. The impurity diffusion coefficient of Al in Cu is determined by extrapolating the interdiffusion coeffficient values to infinite dilution of the alloy i.e CAl →0 and its temperature dependence was also established. The activation energy for impurity diffusion of Al in Cu was found to be 137.1 kJ/mol.