Novel TiC-based ceramic with enhanced mechanical properties by reaction hot-pressing at low temperature

Abstract

Novel TiC-based ceramics were prepared by reactive hot-pressing at 1400–1600 °C using TiC, Si and ZrC powders as raw reactants for the first time. The effects of ZrC addition and temperature on the microstructure and mechanical properties of ceramics were investigated. The Ti3SiC2 phase existed when the content of ZrC was 10 mol%. The Zr-rich solid solution appeared and the Ti3SiC2 disappeared with 30 mol% ZrC addition. The flexural strength of ceramics was improved due to grain refinement by the pinned SiC, the formation of solid solutions and the Ti3SiC2 phase. The main toughening mechanism can be crack bridging by the layered Ti3SiC2 and crack deflection by the ZrSi particle. TiC-36 mol% Si-10 mol% ZrC (raw composition) exhibits good comprehensive mechanical properties (Vickers hardness of 21.8 GPa, flexural strength of 580 MPa, and indentation fracture toughness of 6.7 MPa m1/2), which reach or exceed most TiC-based ceramics in previous reports.