Processing and Electrical Properties of Nano-Al2O3/Cu Composites

Copper matrix composites (CMCs) are widely used in electrical equipment and electrical contact materials due to their excellent electrical properties. Al2O3 powders are widely used as a reinforcing agent to enhance mechanical properties of MMCs. The xAl2O3/Cu (x =0, 0.2, 0.5, 0.7, and 1.0wt. %) composites were prepared via vacuum arc melting method. The mechanical and electrical properties were obtained by measuring the hardness and conductivity. The morphology of copper and Al2O3/Cu composites was characterized by optical microscopy (OM) and scanning electron microscopy (SEM). With the addition of Al2O3 from 0.2 wt. % to 1.0 wt. %, the relative densities of composites decreased from 98.5% to 97.0%. The hardness of the composites increased with increase in the Al2O3 powders content. The hardness of 1.0Al2O3/Cu composites was 57.9 HB, which was higher than that of pure Cu by 18.6%.. With the addition of Al2O3, the IACS% of Al2O3/Cu composites decreased from 88.97 to 86.16.