Properties of Si_3N_4-TiN composites fabricated by spark plasma sintering by using a mixture of Si_3N_4 and Ti powders

摘要

Si_3N_4-TiN composites were successfully fabricated via planetary ball milling of 70 mass percent Si_3N_4 and 30 mass percent Ti powders, followed by spark plasma sintering (SPS) at 1250-1350 deg C. The sintering mechanism for SPS was a hybrid of dissolution-reprecipitation and viscous flow. The electrical resistivity decreased with increasing sintering temperature up to a minimum at 1250 deg C and then increased with the increasing sintering temperature. The composites prepared by SPS at 1250-1350 deg C could be easily machined by electrical discharge machining. Composite prepared by SPS at 1300 deg C showed a high hardness (17.78 GPa) and a good machinability.