Preparation of Al2O3/TiC micro-composite ceramic tool materials by microwave sintering and their microstructure and properties

In this study a series of tests were conducted in order to investigate the feasibility of producing Al2O3/TiC micro-composite ceramic tool materials with high mechanical properties by microwave sintering. Multiphase materials were simultaneously added into the Al2O3/TiC system. The samples were sintered in a multimode microwave furnace at 2.45 GHz on the base of powder bed which consists of graphite powder and silicon carbide. The influence of the sintering temperature on the relative density, mechanical properties and microstructure was studied. The experimental results showed that the Al2O3/TiC micro-composite which was sintered at 1700 °C in argon for 10 minutes had optimal mechanical properties. Its relative density, fracture toughness and Vickers hardness were 99.2% theoretical density (TD), 5.18 MPa m1/2 and 21.2 GPa, respectively. Phase composition and microstructure analysis showed that the microwave sintered Al2O3/TiC micro-composites had a tendency to obtain a homogeneous microstructure in a short time, and restrain the reaction between Al2O3 and TiC.