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

Abstract

Dense B₄C-based materials containing up to 4.9 wt % Si have been produced by hot pressing in the temperature range 1600–1700°C. In this process, the silicon melts to form a liquid phase, which improves the sinterability of the material. The boron carbide partially dissolves in the liquid Si to form silicon carbide between the B₄C grains. The relative density, bending strength, Vickers hardness, and fracture toughness of the materials obtained in this study are 99.0 ± 0.1%, 584 ± 12 MPa, 39.4 ± 0.1 GPa, and 5.3 ± 0.2 MPa m^1/2, respectively. The materials experience predominantly transcrystalline fracture.