Methods of Testing for Thermal Stress Resistance

The methods of testing for heat resistance currently used in practical research are not yet properly classified (let alone standardized); however, attempts in this field have been reported occasionally [19, 29–31, 88–91].

The standards adopted in various countries are mainly concerned with methods that give a qualitative characterization of heat resistance only. In conformity with the standards of Russia, Great Britain, U.S. and France [17, 92], ceramic articles (bricks, refractory panels, etc.) or cylindrical or prismatic specimens of specified size are heated to a certain temperature in air and, after a period of time, are cooled in a steam of water or air. Finally, the number of such thermal test cycles is determined that lead to loss of weight or to cracking, spalling or fracture.

The advent of new technologies (especially in space, aviation and nuclear power engineering) and the use of new materials and products operating under severe conditions make it necessary to develop quantitative methods for the evaluation of heat resistance and classification and appropriate methodology of testing mimicking real thermal loading conditions [92].