Densification and Mechanical Properties of B4C Based Composites Sintered by Reaction Hot-pressing

摘要

Boron carbide (B4C) possesses unique physical and thermal properties.In this paper,B4C based composites toughened by TiB2 were fabricated by in-situ reaction sintering with the original microcrystalline powders B4C,TiO2 and glucose.The influences of sintering temperature and content of TiO2 on the sintering behavior and mechanical properties were investigated.(TiB2,Al2O3)/B4C and (TiB2,SiC)/B4C composites with almost fully dense were fabricated by using additives of Al2O3 and Si powders and sintering at 1950°C and 1900°C,the fracture toughness of composites reach to 7.09 and 6.35 MPa.m1/2 respectively.The analysis of microstructure shows that the main toughen mechanism is the crack deflection due to the existence of residual stress.