Environment‐oriented low‐cost Al ₂ O ₃ ceramics with hierarchical pore structure fabricated from SiC solid waste

Abstract Environment‐oriented low‐cost Al ₂ O ₃ reticulated porous ceramics with hierarchical pore structure were fabricated by the polymer sponge replica method combined with vacuum infiltration methods, using Al ₂ O ₃ powders and SiC solid waste (SCSW) as raw material and a pore‐forming agent. The effects of SCSW addition amount on mechanical properties, microstructure and pore size of Ceramics were investigated. The results showed that the thermal shock resistance of specimens increased gradually with addition of SCSW, however, the median pore diameter increased firstly and then decreased, due to the generation of mullite and liquid phase. After calcination, the residual stress was generated within the coating layer because of the difference in the thermal expansion coefficients of ceramic matrix and coating layer, which could improve the properties of Ceramics by deflecting and bifurcating crack growth path. The results showed that the best dosage of SCSW was 30 wt%.