Production of electrical conductive B4C particle reinforced copper matrix composi̇e

In this study, the effect of the reinforcement rate and size on mechanical and electrical properties of Cu-B4C composites was investigated. The used samples were produced through powder metallurgy method. Copper powders with 60 µm particle size were used as the matrix material and B4C powders with two different particle size (7 and 60 µm) were used as the reinforcement material. The Cu matrix was reinforced with B4C powders at ratios of 0, 1, 3 and 5 % by weight. The prepared powders mixtures were pressed with a load of 250 bar and sintered at 750 C˚ for 2 h. The samples were embedded in graphite to prevent the oxidation during sintering. The electrical and mechanical properties of the obtained composites were determined. For this purpose, optical, SEM-EDS and XRD analyses of composites were done. Then, the density, electrical conductivity, hardness and wear rates of the composites were determined. It was seen that the reinforced particles was not completely homogeneous in matrix. A small amount of the oxidation was occurred at the composite samples. Depending on the reinforcement process, the hardness of the composites significantly increased. Compared with unreinforced samples, the electrical conductivity of the composites was generally low. Also, decreasing in the conductivity were not regular due to the oxidation. The wear rates of the composites that were used reinforcement particles with 60 µm particle size has better results than those with 7 µm particle size. As a result, the best suitable results were obtained from the samples that reinforced with 60 µm B4C powders at ratio of 1% by weight.