Processing of Porous SiC by Aluminum-Derived Binders and Sacrificial Porogen Leaching Method

Porous SiC was successfully fabricated by a facile and energy efficient sacrificial porogen leaching method using in situ synthesized aluminum-based binders by reaction bonding at low sintering temperatures of 600-1000 degrees C. Porous SiC ceramics with porosity in the range of 30-58% and compressive strength of 1-33MPa were obtained. Interconnected bimodal pores were produced by both stacking of SiC particles and leach out of salt. During sintering, the aluminum binder experienced metal to ceramic transformations forming various alumina polymorphs (, , and -Al2O3). The porogen content and sintering temperatures significantly influence the properties of porous SiC.