Hot-press sintering of SiC whisker reinforced TiB2-B4C composites and its mechanical property characterizations

Abstract

TiB2-B4C composites modified by SiCW with excellent mechanical properties were prepared using hot-press sintering. The effects of SiCW content on the microstructure, densification behavior and mechanical properties were investigated. The dynamic failure behavior was analyzed through the Hopkinson Bar (SHPB) testing. The results demonstrate that the addition of SiCW can effectively refine the microstructure and simultaneously improve the mechanical properties. The TiB2-B4C composite renforced with 6 wt% SiCW exhibits a nearly full-dense microstructure and excellent mechanical properties. The relative density, flexural strength, Vickers hardness and fracture toughness can reach to 99.95 %, 724 ± 61 MPa, 19.8 ± 0.7 GPa and 6.7 ± 0.3 MPa m1/2, respectively. The dynamic failure behavior exhibits that the damage degree increases with elevated loading speed. Moreover, the single-peak and double-peak of the waveform correspond to the two damage degrees of "broken" and "crushed".