An Evaluation of Cu-B4C Composites Manufactured by Powder Metallurgy

Abstract

In this study, the influences of B4C ratios on some mechanical and physical properties such as relative density, microhardness and electrical properties of cold pressed Cu-B4C composites were investigated. Curve fitting is applied for the estimation of electrical conductivity. Commercial copper powders with 40 mu m particle size were reinforced with B4C, with particle size of 40 mu m, at ratios of 1, 2, 3 wt.%, for improving mechanical properties of copper used as electrical conductor. Cu-B4C composites have been fabricated by powder sintering process at a temperature of 900 C for 2 h. The presence of Cu and B4C, which are dominant components in the sintered composites, were confirmed by X-ray diffraction analysis technique and SEM-EDS. Scanning electron microscope (SEM-EDS) has shown that B4C particles are distributed homogenously in the copper matrix. The relative densities of Cu and Cu-B4C composites, sintered at 900 degrees C, ranged from 95.7 to 91.6%. Microhaidness of composites ranged from 84.5 to 94.6 HS. It was observed that cold pressed Cu-1 wt.% B4C composites revealed promising physical properties. Results of electrical conductivity measurement of Cu-B4C composite material are compared to the results of the model and the overall accuracy level above 96% is obtained.