Interdiffusion in the f.c.c. Phase of Cu-Mn Binary Alloys

Abstract

Interdiffusion coefficients are calculated in the Cu-Mn binary system from 450 to 925 °C. Starting from the diffusion couples between pure Cu and Mn, the solubility limit of the manganese in copper is determined and the interdiffusion characteristics in the f.c.c. solid solution of Cu-Mn alloys are analysed. The interdiffusion coefficients in this binary system are calculated by the den Broeder method. The interdiffusion coefficients are strongly dependent on the composition: their values lie between approximately 10−14 and 4 × 10−9 cm2 s in this temperature range. The Vignes and Birchenall method is used to determine the impurity diffusion coefficients of manganese in pure copper. These coefficients are compared with the tracer diffusion coefficients of Mn54 in copper from the literature. Activation energies, which lie from 155 to 180 kJ/mol, are of a vacancy controlled diffusion mechanism.