Densification, grain growth, and mechanical properties of titanium carbide ceramics

Abstract Titanium carbide (TiC) nano powder was used as the raw material to prepare dense TiC ceramics by spark plasma sintering (SPS) method. The study systematically investigated the effects of sintering temperature and holding time on the densification, grain growth, and mechanical properties of bulk TiC ceramics. Experimental results indicated that high temperature and long holding time promoted sintering densification, which also led to an increase in the grain size of TiC ceramics. Low temperatures and short holding times (1700°C/0 min, 1700°C/5 min, and 1750°C/0 min) suppressed the grain growth of TiC ceramics; however, the residual pores reduced the hardness and fracture toughness. With the increase of sintering temperature and holding time, the relative density of the samples rapidly raised and nano‐grains transformed into micro‐grains. Under the conditions of 1850°C and 30 MPa with a holding time of 15 min, dense TiC ceramics (99.20%) with a grain size of 6.72 µm were obtained with the Vickers hardness of 22.12 GPa and fracture toughness of 4.91 MPa m ^1/2 . Based on the grain growth exponent, it was demonstrated that the grain growth mechanism of TiC ceramics sintered by SPS was primarily dominated by grain boundary diffusion and lattice diffusion.