Abstract

Si₃N₄ particles coated with 20 nm TiN have been sintered by spark plasma sintering (SPS) at 1600 °C. The 25 vol.% TiN ceramic achieved a relative density of 91% without sintering additives. TEM and HREM observations indicate that a glassy phase derived from the Si₃N₄ particles plays a role in densification. Ceramics derived from TiN/Si₃N₄ composite particles containing 25 and 32.5 vol.% TiN possess continuous TiN networks in a Si₃N₄ matrix and their electrical resistivity is of the order of 1 × 10⁻⁴ Ω cm, much lower than that of a mechanical mixture of nano-sized TiN particles and Si₃N₄ particles (1 Ω cm).