ホットプレス法による窒化チタンセラミックスの強度及び電気的特性

抄録

Titanium nitride (TiN) ceramics without additives were fabricated by the hot-pressing (HP), and their mechanical and electrical properties were investigated. Hot-pressing was performed at various sintering parameters such as sintering temperature (1800°-2250°C), sintering time (30-180min), pressing pressure (2-14MPa) and ambient gas (Ar) pressure (vacuum-10atm). Densification was promoted at higher temperature, higher pressing pressure and longer sintering time. The TiN ceramics fabricated by hot-pressing at 2100°C×60min under the pressing pressure of 14MPa in the normal ambient gas pressure showed the representative properties: bulk density; 5050kgm^-3 (relative density 92.8%), Vickers microhardness; 8.52GPa, flexural strength; 265MPa, static modulus (Young's modulus); 387GPa, dynamic modulus; 459GPa, and volume resistivity; 0.360μΩ·m. These properties were affected especially by the ambient gas pressure during hot-pressing. The TiN ceramics prepared in vacuum showed 30-40% augmentation, on the average, in hardness, flexural strength, Young's modulus and resistivity, compared with those prepared under normal (1atm) and higher pressures (5, 10atm). TiN ceramics with high mechanical properties were obtained by sintering in vacuum.