Microstructure and properties of W-25 wt% Cu composites reinforced with tungsten carbide produced by an in situ reaction

Abstract

W–Cu composites that are strengthened with tungsten carbide ceramic particles have been proposed thanks to their high melting point, high hardness and excellent high-temperature mechanical properties. In this paper, tungsten carbide-reinforced W-25 wt% Cu composites were fabricated via an in situ synthesis technique that used mixed tungsten, copper and graphite powders. The impact of the graphite content on the microstructure and properties of the W–Cu composite was investigated. The results showed that tungsten carbide phases formed through the carbonization reaction of tungsten and graphite at high temperature. With the generation of tungsten carbide phases, the hardness, vacuum arc erosion resistance, high-temperature strength and wear resistance of the W–Cu composites were improved. The improvement was very significant for the W–Cu composites with an increase in the graphite content. However, the electrical conductivity was slightly sacrificed for the W–Cu composites. Moreover, the effects of the graphite on the comprehensive properties were evaluated and compared with those of reinforced with CNTs. Based on the laboratory properties and preparation cost of W–Cu composites, graphite can be used for the industrial fabrication of in situ self-generated tungsten carbide-reinforced W–Cu composites.