Characterization of spark plasma sintered TiC–Si₃N₄ ceramics

This research aimed to compare the TiC and TiC-Si₃N₄ ceramics in terms of sintering behavior and physical-mechanical characteristics. The spark plasma sintering (SPS) process was used as the fabrication route with the sintering conditions of 1900 °C, 7 min, and 40 MPa. The results confirmed the deposition of carbon in the monolithic TiC during the SPS process. Incorporating Si₃N₄ led to the advancements of some chemical reactions between TiC, Si₃N₄, and carbon ingredients, leading to the in-situ formation of SiC and N₂ phases. Although the thermodynamic assessment suggested the in-situ synthesis of the TiN phase, too, any amount of it was identified in neither the X-ray diffractometry pattern nor field emission scanning electron microscopy images. Based on the thermodynamic study, TiN possibly reacted with the deposited carbon, forming in-situ TiC and N₂. Thermal conductivity, Vickers hardness, and flexural strength of 10.1 W/mK, 2966 HV_0.1kg, and 219 MPa, respectively, were obtained for the TiC-Si₃N₄ ceramic.