Tribological and mechanical properties of copper matrix composites reinforced with carbon nanotube and alumina nanoparticles

Abstract

Copper is widely used as electrical contact materials due to its excellent thermal and electrical conductivity. However, low strength and poor wear resistance restrict its practical applications. Herein, we report a high-performance copper matrix composite reinforced with carbon nanotubes (CNT) and alumina (Al2O3) nanoparticles prepared by powder metallurgy route. The microstructure, density, hardness, tensile strength and tribological properties were studied. CNTs and Al2O3 were successfully mixed with copper powders by acid treatment and mechanical milling. After sintering, CNTs and Al2O3 were uniformly distributed around the grain boundaries and limited the grain growth. Furthermore, all copper matrix composites showed decreased density, but increased hardness and tensile strength compared with the copper matrix. More importantly, the incorporation of CNTs and Al2O3 significantly improved the tribological properties of copper matrix. This is because Al2O3 nanoparticles with high strength enhanced the wear resistance by dispersion strengthening, while CNTs served as solid lubricant greatly improving the anti-friction properties. Besides, the friction coefficient as well as wear rate increased with higher load and sliding speed. The Cu-1.5CNTs-0.5Al2O3 composite had the optimal hardness, tensile strength, anti-friction, and wear-resistance properties.