In situ synthesis of (TiB2+SiC)/Ti3SiC2 composites by hot pressing

Abstract Based on thermodynamic analysis, fully densified (TiB 2 + SiC)/Ti 3 SiC 2 composite ceramics were in situ prepared by hot-pressing at 1350–1500 °C using TiH 2 , TiC, Si, B 4 C and Al powders as raw materials, in which the main phases are Ti 3 SiC 2, TiB 2 and SiC. As reinforcing agents, columnar TiB 2 grains and granular SiC grains, incorporated by in situ reaction exhibit significant synergistic strengthening and toughening effect to the Ti 3 SiC 2 matrix and the composites show excellent mechanical properties. The materials sintered at 1450 °C possess the optimized microstructure and consequently the optimal mechanical properties, i.e., bending strength of 861 MPa, fracture toughness of 9.56 MPa·m 1/2 and Vickers hardness of 9.79 GPa.