The effects of B4C addition on the microstructure and mechanical properties of SiC prepared using powders recovered from kerf loss sludge

Recent progress in B4C–SiC composite ceramics: processing, microstructure, and mechanical properties

“…Furthermore, the addition of B 4 C reduces the abnormal growth of SiC grains; thus, the SiC-5 vol% B 4 C ceramics exhibit a finer microstructure than pure SiC ceramics. Cho et al 69 mentioned that the relative density of the pressureless sintered SiC ceramics decreases with the addition of B 4 C particles from 1 to 5 wt%. This phenomenon can be explained by the fact that the B 4 C grains existing between SiC grains impede mass transport through surface diffusion; thus, the grain growth of SiC is slowed down with the increase in B 4 C addition, resulting in the formation of large amounts of pores.…”

“…Higher mechanical properties of SiC-5 vol% B 4 C ceramics are attributed to the finer microstructure and less strength-controlling flaws like porosity as compared to pure SiC ceramics. Cho et al 69 mentioned that the hardness reduces but the fracture toughness increases when the content of B 4 C increases from 1 to 5 wt% in the SiC-B 4 C ceramics. The reduced hardness is attributed to the increased porosity of the ceramics, while the increased fracture toughness is caused by the toughening mechanisms of crack bridging, crack deflection, and crack branching, resulting from the presence of increased B 4 C at the grain boundary.…”