The stabilization of wet foam was an important parameter for obtaining a large volume of dried foam in SiC porous ceramics. Octylamine was used as a foam stabilizer, which modifies the particle surface. Albumin was added as a foaming agent to achieve a higher volume of wet foam with higher stability. Viscosity of the colloidal suspension varying with albumin content was found to be typical, as on increasing albumin content, the slurry showed shear thickening behavior. The viscosity of the slurry was found to be increased, hindering thick strutting. This gave more stability to the wet foam on mechanical frothing, to produce porous ceramics on sintering. In terms of the rheological properties, wet foams were characterized as a function of air content, wet foam stability, bubble size, and relative bubble size. Controlling the air content inside the foam, the wet foam stability of the wet foams was improved from 20 to 90% with the increment of albumin content. Proof of the stability is shown by the controlled increment of the relative bubble size to less than 2.5 times. With all these improved parameters upon sintering, highly interconnected pore structure was achieved for various applications.

Keywords: SiC, Rheological properties, Foaming agent, Wet foam, Porous ceramics