Thermal shock and chemical corrosion resistance of oxide bonded porous SiC ceramics prepared by infiltration technique

Using the water- and air-quenching technique, the thermal shock resistance to cooling was evaluated as a function of quenching temperatures and quenching cycles for oxide bonded porous SiC ceramics prepared by infiltration technique. It was observed that the residual strength of the quenched samples decreases with increase in the quenching temperature. However residual strength becomes independent of quenching cycles after certain cycles since the thermal shock produced by repeated cycles remained almost constant. The hot corrosions of SiC samples exposed to Na2SO4 salt were performed at 1000 degrees C. The weight loss, strength reduction and morphology evolution of the SiC specimens during corrosion were revealed and explained. The chemical and thermal shock resistance results suggest a potential advantage of porous SiC ceramics prepared by infiltration technique for several industrial applications. (C) 2018 Elsevier B.V. All rights reserved.