Green synthesis of porous SiC ceramics using silicon kerf waste in different sintering atmospheres and pore structure optimization

Abstract This work reported the feasibility of using silicon kerf waste as raw material for the preparation of porous SiC ceramics, as well as effects of sintering atmospheres and additives on the properties of as-prepared ceramics. Samples sintered in Ar, N2, and carbon embedded atmospheres exhibited entirely different properties because of the formed bonding phases of SiCw, Si3N4/Si2N2O, and Si2N2O. Moreover, the apparent porosity and closed porosity of the samples were increased with the additions of feldspar and starch. Preferably, a series of porous SiC ceramics with apparent/closed porosity of 24.15%–59.59%/5.83%–14.77%, bulk density of 1.13–1.91 g cm−3, cold compressive strength of 34.73–249.89 MPa, and thermal shock resistance of 110–118 cycles was synthesized at 1500 °C in carbon embedded atmosphere. Therefore, a low-cost and facile synthesis strategy for preparing high-quality porous SiC ceramics from solid waste is proposed in present study.