Material properties of tungsten carbide–alumina composites fabricated by spark plasma sintering

Abstract The densification behavior of WC–Al 2 O 3 composites prepared via spark plasma sintering (SPS) was investigated. The initial materials were fabricated using a metal-organic chemical vapor deposition process in which W(CO) 6 was used as a precursor and Al 2 O 3 powder was used as the matrix in a spouted bed. The decomposed W(CO) 6 produced W species that coated Al 2 O 3 . Then, carburization, using a mixture of CH 4 –H 2 gas, was used to form tungsten carbide–alumina composite powder. This powder was sintered via SPS in the temperature range of 1200–1350 °C, which produced several secondary phases, namely W, WC, and W 2 C. At the highest sintering temperature (1350 °C), the intermediate phase WC decomposed to form W 2 C. The material properties of the SPS-treated samples, including density, hardness, and electrical resistivity, were investigated. The hardness and electrical resistivity of WC–Al 2 O 3 composites were found to be approximately 22.4 GPa and 4.9×10 9 Ω cm, respectively.