High-performance B 4 C–TiB 2 –SiC composites with tuneable properties fabricated by reactive hot pressing

Abstract

In this work, we systematically studied the effects of powder characteristics (B 4 C, TiC and Si powders) on the existential form of toughening phases (SiC and TiB 2 ) as well as the overall microstructure and properties of B 4 C–TiB 2 –SiC composites fabricated by reactive hot pressing. The particle size of the TiC powder plays a largely determining role in the development of novel toughening phases, the TiB 2 –SiC composite structure, that are formed in the B 4 C matrix, while the Si particle size affects the agglomerate level of the SiC phase. The TiB 2 –SiC composite structure and SiC agglomerates enhance the fracture toughness, but decrease the flexural strength. Both the microstructure and mechanical properties of B 4 C–TiB 2 –SiC composites can be effectively tuned by regulating the combinations of the particle sizes of the starting powders. The B 4 C–TiB 2 –SiC composites demonstrate flexural strength, fracture toughness and Vickers hardness in the respective range of 567–632 MPa, 5.11–6.38 MPa m 1/2 , and 34.8–35.6 GPa. © 2019 Elsevier Ltd