Microstructure and Performance of Al2O3-Reinforced Copper Matrix Composites Prepared by Oscillatory Hot-Pressing Sintering

Abstract

In order to enhance the strength and wear resistance of pure copper without obvious sacrifice of high electrical conductivity, Al2O3 particle-reinforced copper matrix composites with different volume fractions of Al2O3 were fabricated via the oscillatory hot-pressing sintering process. The effects of Al2O3 content on the densification, microstructure, mechanical properties, electrical conductivity, and wear behaviors of the composites were systematically investigated. The results showed that oscillatory pressure effectively inhibited pore formation, and Al2O3 particles were uniformly distributed within the copper matrix. With the increase in the Al2O3 volume fraction, the densification of the composites decreased slightly, while the hardness, compressive strength and wear resistance were continuously improved. By contrast, the electrical conductivity declined marginally and the friction coefficient rose. The 10 vol.% Cu-Al2O3 composite exhibited the optimal comprehensive wear resistance, with a hardness of 123 HV and an electrical conductivity maintained at 80.2% IACS. The wear mode of the composites gradually shifts from single adhesive wear of pure copper to the combined effect of abrasive wear and oxidative wear.