Thermal stability of heavily deformed Ag–10 wt.%Cu microcomposite wires

Abstract

An Ag–10 wt.%Cu in situ microcomposite was produced by heavy deformation technique. Both isochronal and isothermal annealing were applied to study the microstructures, properties and thermal stability of this composite. A certain precipitation strengthening was observed during isochronally annealing at 200 °C. When the annealing temperatures were above 300 °C, continuous Cu filaments formed during heavily deformation were gradually transformed into Cu particles aligning along the wire axis because of some processes such as recrystallization and grain growth happened. The mechanical strength of this microcomposite decreased and electrical conductivity increased during annealing process in this temperature range. Electrical conductivity was used to measure the degree of transformation during the isothermal process. Combined with the Komolgorov–Johnson–Mehl–Avrami model, activation energy of 122.5 ± 6.5 kJ/mol was determined for this process. The reason for relatively low activation energy is also discussed.