Evaluation of Air Permeation Behavior of Porous SiC Ceramics Synthesized by Oxidation-Bonding Technique

Porous SiC ceramics were synthesized by oxidation bonding of compacts of commercial -SiC powder at 1300 degrees C. Different volume fractions of petroleum coke powder were used for variation of porosity of ceramics from 36% to 56%. The material exhibited variations of pore size from 3 to 15m, flexural strength from 5.5 to 29.5 MPa, and elastic modulus from 3.3 to 27.6 GPa. Air permeation behavior was studied at 26-650 degrees C. At room temperature Darcian (k(1)) and non-Darcian (k(2)) permeability parameters vary from 1.64 to 18.42x10(-13)m(2) and 0.58 to 2.95x10(-7)m, respectively. Temperature dependence of permeability was explained from structural changes occurring during test conditions.