Integrated high strength and high toughness induced by elongated TiB2 grains in reactive sintered TiB2-TiC-SiC ceramics

Although the addition of other phases into TiB2 matrix to form ceramic composites has been widely used to improve the mechanical properties of monolithic TiB2 ceramics, it is still difficult to greatly enhance the flexural strength and fracture toughness simultaneously. In this work, TiB2-TiC-SiC composites were successfully prepared by reactive spark plasma sintering of Ti3SiC2-B4C-Ti powder mixtures. During the sintering process, TiB2 grains grew into an elongated morphology, endowing the composites with integrated high strength and high toughness. The growth mechanism of TiB2 grains was attributed to the evaporation-condensation kinetics induced by the presence of B2O3. These findings can accelerate the exploration of ceramic composites with excellent comprehensive properties.