Preparation and properties of porous SiC–Al2O3 ceramics using coal ash

• DOI: 10.1111/ijac.13080
• Publication Date: 2018-07-31T22:35:07Z
• Authors: Yue Yin; Beiyue Ma; Chuanbo Hu; Guoqi Liu; Hongxia Li; Chang Su; Xinming Ren; Jingyu Yu; Yaran Zhang; Jingkun Yu
• Keywords: Thermal shock; Carbothermic reaction

Abstract In this paper, we first reported that porous SiC–Al 2 O 3 ceramics were prepared from solid waste coal ash, activated carbon, and commercial SiC powder by a carbothermal reduction reaction ( CRR ) method under Ar atmosphere. The effects of addition amounts (0, 10, 15, 20 wt%) on the postsintering properties as‐prepared ceramics, such as phase composition, microstructure, apparent porosity, bulk density, pore size distribution, compressive strength, thermal shock resistance, diffusivity have been investigated. It was found final products are β‐SiC α‐Al . Meanwhile, SEM shows pores distribute uniformly body gradually contacts closely in ceramics. to be remarkably improved adding proper (10, wt%). However, further increasing amount leads decrease resistance mechanical properties. Porous doped with 10 wt% sintered at 1600°C for 5 hours median diameter 4.24 μm, room‐temperature strength 21.70 MP a, porosity 48%, 0.0194 cm /s successfully obtained.