Study on Microstructure and Properties of Silver-Plated Alumina-Reinforced Copper Matrix Composites

Alumina (Al2O3) reinforced copper matrix composites are widely used in the electronic industry, rail transit, and other fields due to their excellent electrical conductivity, ductility, and wear resistance. However, due to problems such as non-wetting and thermal expansion differences between alumina and Cu, weak interfacial bonding can easily reduce physical and thermal properties. A uniform silver layer was deposited on Al2O3 via chemical plating to enhance interface bonding with copper. Al2O3@Ag/Cu composites with 1–3 wt.% Al2O3 were prepared by rapid hot-press sintering. The effects of plating temperature and Al2O3 content on microstructure and properties were investigated. The results show that the optimum coating temperature is 25 °C, and a thin and uniform silver coating can be formed. This effectively improved Al2O3–Cu interface bonding while maintaining 77.8% of copper’s thermal conductivity (320.7 W/(m·K)). The composites showed improved wear resistance with increasing Al2O3 content. At 3 wt.% Al2O3@Ag, the wear rate was 3.36 × 10−5 mm3/(N·m), 84.4% lower than pure copper, with plow groove wear as the main mechanism.