Spark plasma sintering of B4C-TiB2-SiC composite ceramics using B4C, Ti3SiC2 and Si as starting materials

Almost fully dense B 4 C-TiB 2 -SiC composite ceramics with high flexure strength and good fracture toughness were fabricated through in-situ reaction between B 4 C, Ti 3 SiC 2 and Si using spark plasma sintering method at a relatively low temperature of 1650 °C. The intergranular and intragranular structure containing nanoparticles with different phase were introduced into the composite ceramic. The nano and micro particles in the microstructure formed a multi-scale particles reinforced structure. The refined matrix grains and the multi-scale reinforcing particles had a synergetic effect on improving the mechanical properties of the composite ceramics. As a result, B 4 C-TiB 2 -SiC composite ceramic with 30 wt% (TiB 2 + SiC) exhibits low density and optimum mechanical properties with high flexural strength of 531.2 MPa, good fracture toughness of 5.77 MPa m 1/2 and moderate micro-hardness of 28.6 GPa.