Si‐rich pressureless sintering of the gelcasted Ti 3 SiC 2 bulk ceramic

The Si‐rich pressureless sintering was used to fabricate the Ti 3 SiC 2 bulk ceramic. The results show that the optimized Ti 3 SiC 2 suspension could be prepared at the absolute value of zeta potential, pH level, PAA‐NH 4 dosage, and solid loading of 62.1 mV, 11, 2.0 wt%, and 50 vol%, respectively. The channels existing in the Si‐free sintered body facilitated the reactants and products to diffuse to the interior and out of the Ti 3 SiC 2 matrix, thereby forming the porous reaction layer of TiC‐Ti 3 SiC 2 . The co‐effects of the channels and the reaction layer of TiC‐Ti 3 SiC 2 severely lowered mechanical properties of the Si‐free sintered Ti 3 SiC 2 ceramic. On the contrary, the Si‐rich sintering method isolated the volatile carbon and established a closed Si‐rich atmosphere to sinter the green Ti 3 SiC 2 cylinder. The porosity, density, fracture toughness, hardness, and flexural strength of the Si‐rich sintered Ti 3 SiC 2 ceramic reached 0.74 vol%, 4.36 g/cm 3 , 5.49 MPa·m 1/2 , 4.03 GPa, and 383 MPa, respectively.