High-strength and high-conductivity Cu-0.7Mg-0.1Ca alloy fabricated via heat treatment and severe plastic deformation

In this research, the effect of annealing in combination with severe plastic deformation (SPD) by the MaxStrain component of the Gleeble thermo-mechanical testing device on the microstructural characteristics, tensile behavior, and electrical conductivity of a Cu-0.7Mg-0.1Ca (wt%) alloy was investigated. The as-cast material was subjected to two treatments: annealing at 923 K for 15 min, followed by cooling in air, and annealing at 923 K for 75 min, followed by quenching in agitated water, which resulted in irregular and partially spheroidized Cu5Ca particles. Subsequent MaxStrain deformation resulted in a remarkable grain refinement by dynamic recrystallization (DRX), in which the annealed and quenched sample exhibited a higher DRX fraction than the annealed and air-cooled sample. As a result, the annealed and quenched samples showed a better synergy between strength and ductility, while these improvements were accompanied by only ~1% reduction in electrical conductivity. Accordingly, the present work demonstrated that annealing and subsequent SPD processing is an effective method for processing high-strength and high-conductivity (HSHC) copper alloys.