Preparation, microstructure and properties of copper-coated flake graphite and SiC particles hybrid reinforced aluminum matrix composites

Metal matrix composites with outstanding tribological performance and balanced mechanical and thermal properties have great potential for applications in lightweight wear-resistant components and precision machinery. In this work, we present an effective strategy for fabricating copper-coated flake graphite and SiC particles hybrid reinforced aluminum matrix composites (Cu@Gr-SiC-Al composites) by implementing powder metallurgy and fast hot-pressing sintering. First, copper-coated flake graphite (Cu@Gr) was synthesized via electroless plating. The dense and uniform copper coating improved the interfacial bonding between the flake graphite and the aluminum matrix. Then, SiC particles were introduced as a hybrid reinforcement to enhance the load-bearing capacity of the composite. The effects of varying Cu@Gr contents (with a fixed SiC content of 2 wt.%) on the microstructure, physical properties, mechanical properties, and tribological behavior of the composites were thoroughly investigated. At a Cu@Gr content of 4 wt.%, the Cu@Gr-SiC-Al composite exhibited a wear rate of 3.237 × 10 -4 mm 3 /(N·m), which is 46.7% lower than that of the composite reinforced with SiC alone. Overall, the Cu@Gr-SiC-Al composite exhibited great potential for the design and application of tribological materials due to its stable mechanical properties and excellent wear resistance.