Abstract
The composite ceramics of the TiN-TiB2 system, which have high electrical conductivities and can be used for electric discharge machining, were sintered at 2100°C for 3.6 ks in the ambient Ar gas of normal pressure. The mechanical and electrical properties of the ceramics were characterized. The TiN-TiB2 composite ceramics, which contained 20-60 mass%TiB2, had higher relative densities of about 87%. Vickers hardness, flexural strength, fracture toughness, Young's modulus and shear modulus of the composite ceramics were about 1.2-2.3 times higher than those of pure TiN or TiB2 ceramics having relative densities of about 83 and 74%, respectively. The mechanical properties of the ceramics depended principally on the relative densities, while the electrical conductivity was dependent on the contents of TiN and TiB2.
