Preparation and properties of copper matrix composites reinforced with Al2O3 particle fiber blend

To develop copper-based composite materials with high strength, high wear resistance, and high electrical conductivity, plasma discharge sintering (SPS) was employed in this study to prepare copper-based composite materials reinforced with mixed Al2O3 particles (0~4%) and Al2O3 fibers (0~4%). The influence of Al2O3 particle/fiber content on the microstructure, mechanical properties, and physical properties of the composite materials was investigated. It is found that the microstructure of the Al2O3 particle/fiber reinforced copper-based composite material is fine, uniform, and highly dense, exceeding 95% density. With increasing Al2O3 particle/fiber content, the tensile strength and hardness of the composite material gradually increase, while electrical conductivity and wear resistance decrease slowly. When the Al2O3 particles are at 2% and Al2O3 fibers are at 4wt.%, the material exhibits excellent tensile strength (257 MPa) and wear resistance (friction coefficient 0.142, wear rate 2.57×10-5 mm3/(N·m)), with a tensile strength about 23% higher than that of pure copper, and its wear resistance is 5.5 times higher than that of pure copper, while maintaining a very high electrical conductivity (64.00% IACS). In-depth analysis reveals that its fracture mechanism involves tough pits formed by Al2O3 particles and the pull-out and fracture of Al2O3 fibers, while the wear mechanism is fatigue wear.