Preparation of Silicon Carbide Reticulated Porous Ceramics Sintered at Low Temperature with PCS as Sintering Additive

Silicon carbide(SiC) reticulated porous ceramics(RPCs) were fabricated by polymer sponge replicas method with PCS as sintering additive.Slurry with PCS as binder was recoated on the SiC reticulated porous performs by centrifuging process.The effects of sintering temperature and holding time on SiC RPCs microstructure and properties were investigated.On consideration of the strength and strut porosity of RPCs,the RPCs can be sintered at 1100℃ holding for 1h.With PCS slurry as recoating slurry,the strut thickness of SiC RPCs is very uniform.The optimal compressive strengths of the RPCs prepared by 10PPI sponge and 25PPI sponge are(1.08±0.21)MPa and(2.19±0.32)MPa,respectively.The refectory of them is as high as 1690℃.At the same time,the RPCs with PCS as sintering additive have good thermal shock resistance.After quenched at 1400℃,thermal shock resistance parameter of the RPCs prepared with 25PPI sponge is only 0.36.