2019 Volume 66 Issue 11 Pages 530-535
Other transition metal carbides NbC, TaC, WC, and ZrC added TiC–SiC composite ceramics were sintered at 1800°C and 1850°C using a resistance-heated hot pressing machine. The raw materials TiC, α-SiC and the reaction products TiC-based solid solutions were detected in the ceramics. The highest Young’s modulus value of 477 GPa was obtained for the ceramics with 17 mol% TaC. The Vickers hardness of TiC–SiC composite ceramics was increased by the addition of TaC, ZrC, and a small amount of NbC, reaching 21 GPa at 12 mol% TaC. There was a correlation between the hardness of TiC–SiC composite ceramics and the average grain size of TiC. The fracture toughness of TiC–SiC composite ceramics was increased with increasing WC amount below 5 mol%, and TaC below 12 mol%. The addition of 12 mol% TaC to TiC–SiC composite ceramics was increased not only the hardness but also the fracture toughness, its value reaching 6.1 MPa m0.5.
