[en] TiB₂-TiC-SiC ternary phase ceramics have been prepared by high-gravity activated combustion synthesis using (Ti-Si-B₄C) mixing powders. XRD, FESEM and FETEM results show that the ceramic matrix was mainly composed of TiB₂, TiC and β-SiC. Uniformly-distributed TiB₂ platelets formed the skeleton of ceramics, and irregular TiC and β-SiC solids were embedded between TiB₂ platelets. The relative density, Vickers hardness and fracture toughness of the ternary phase ceramics were measured with values of 97.9 %, 22.2 GPa and 10.1 MPa·m^0.5. The high-fraction randomly-orientated TiB₂ platelets were found to induce continuous crack deflection, and consumed more energy from the crack tip, thereby enhanced the strength and toughness of TiB₂-TiC-SiC ceramics. (paper)

[en] TiB₂-TiC solidified ceramics were fabricated by taking combustion synthesis with the blends of (B₄C+Ti) powders and (CrO₃+Al) thermite in the high-gravity field of 300 g. XRD, FESEM and EDAX results showed that the composites mainly were consisted of fine plate-like TiB₂, irregular TiC and (Cr, Ti)₃B₂ solids and Al₂O₃ inclusion particles. The introduction of high-gravity field was thought to bring about pure Ti-Cr-B-C liquid. Rapid solidification was a key factor for the achievement of fine-grained microstructure, which in turn was responsible for the improved wear properties of the composites.Vickers hardness, fracture toughnessandmaximum wear rate of the composites were measured 20.8GPa, 13.4MPa·m⁰⁵ and 2.5×10^-7g·(N·m)^-1, respectively.The excellent wear resistance of the composites was considered resulting from the contribution of the high-toughness, high-hardness, fine-grained TiB₂ plate-like primary phases. (paper)