Portal de Periódicos da CAPES

Fabrication of porous SiC ceramics through a modified gelcasting and solid state sintering

2015; Elsevier BV; Volume: 654; Linguagem: Inglês

10.1016/j.msea.2015.12.061

1873-4936

Feng Wang, Jinwei Yin, Dongxu Yao, Yongfeng Xia, Kaihui Zuo, Jiaqiang Xu, Yu‐Ping Zeng,

Recycling and utilization of industrial and municipal waste in materials production

With starch as pore forming agent, porous silicon carbide (SiC) ceramics were successfully fabricated by gelcasting. A novel and simple gelling system of isobutylene and maleic anhydride (Isobam) can gel in air at room temperature was used. The rheological behaviors of SiC slurries were investigated as a function of starch content. The gelled SiC green bodies were sintered at 2050–2150 °C through solid state sintering with B4C and carbon as sintering additives. Porosity of the porous SiC ceramics sintered at 2100 °C was well controlled from 34.20% to 42.68% with the starch content increasing from 0 to 20 wt%. With increasing the sintering temperature from 2050 to 2150 °C, flexural strength and porosity of porous SiC ceramics with 20 wt% starch varied from 61.0 to 128.0 MPa and 48.1% to 34.2%, respectively. The porous SiC ceramics fabricated with 20 wt% starch addition and sintered at 2100 °C were proved to possess excellent thermal shock resistance. The ceramics after water-quenching at 1500 °C showed an average flexural strength of 95.8 MPa, which was higher than the strength of samples without quenching.