Influence of dc electric current on the hardness of thermally aged Cu-Cr-Zr alloy

During the aging treatment of solution treated and cold-worked Cu-Cr-Zr alloy a dc electric current was imposed to the samples. The effect of the current on microstructure and hardness of the alloy was investigated by means of transmission electron microscopy and Vickers hardness measurement. A maximum improvement in microhardness of about 20 HV was observed at a current density of 0.35 A/mm2. In general, the softening temperature of the alloy was delayed for about 50-75 °C. As a result of the current imposition during the aging treatment the Cr precipitation was obviously improved. Finally, the finer Cr filament is attributable to the different electrical conductivities between the Cr filament and the Cu matrix.