Effect of Si on the microstructure and properties of hot-pressed sintered B4C

SiB6-B4C ceramic composites were fabricated by hot-pressed sintering technology using Si as sintering aids. The sintering process and mechanism of Si-B4C ceramics were studied by theoretical calculation, XRD and SEM. The results indicate that Si performances a significant effect on B4C ceramics density sintering and the in-situ generated SiB6 could improve the mechanical properties of B4C ceramics. The optimal addition of Si is 10wt%. Pre-sintering process is benefit for Si-B4C ceramics sintering. The flexural strength, fracture toughness and HRA hardness of B4C ceramics reached 447.3 MPa, 4.42 MPa · m1/2 and 94 separately when they were pre-sintered at 1000-1400°C for 8 h.