Preparation of porous carbides by reactive sintering

Three porous carbide ceramics (Cr₃C₂, TiC and WC) were successfully prepared through a reactive sintering process by reducing their oxides (Cr₂O₃, TiO₂ and WO₃) with methane. The surface and cross section morphologies of sintered products were examined by scanning electron microscopy, the microstruetures were characterized, and the reaction dynamics was studied by X-ray diffraction analysis. It is found that the preparation temperatures of porous TiC and WC ceramics should he 1200℃ and 1000℃, respectively, below which intermediates will be produced in the sintering process. The average sizes of both the ceramic struts and pores for porous Cr₃C₂ ceramics prepared by reactive sintering increase with an increase in sintering temperature.