Pressureless sintering of boron carbide with Cr3C2 as sintering additive

In this study, chromium carbide (Cr3C2) was selected as the sintering additive for the densification of boron carbide (B4C). Cr3C2 can react with B4C and form graphite and CrB2 in situ, which is considered to be effective for the sintering of B4C composites. The sintering behavior, microstructure development and mechanical properties of B4C composites were studied. The density of B4C composite increased with the increase of Cr3C2 content and sintering temperature. The formation of liquid phase could effectively improve the densification of B4C composites. The abnormal grains began to appear at 2080 °C. The bending strength could reach 440 MPa for the 25 wt% and 30 wt% Cr3C2 samples after sintering at 2070 °C.