Behavior of microwave-heated silicon carbide particles at frequencies of 2.0-13.5 GHz

Silicon carbide is a key material in microwave (MW) processing and is used widely as a thermal insulator and catalytic agent. In this study, we experimentally investigated the temperature dependence of the MW-absorption properties of SiC particles at frequencies of 2.0-13.5 GHz. We heated SiC particles of different sizes using MW radiation. The heating behaviors of the particles were then compared with their MW-absorption properties. The heating behavior of the particles was dependent on their radii; this result was in keeping with theoretical predictions. Furthermore, the beta-SiC particles exhibited anomalous behaviors when subjected to microwave heating at temperatures of 1100 degrees C and higher. These behaviors were attributable to the transformation of beta-SiC into the alpha-phase. The underlying mechanism for this transformation is discussed on the basis of the results of X-ray diffraction analysis. (C) 2014 AIP Publishing LLC.