Application of the Statistical Weibull Theory to Estimate the Thermal Shock Resistance of Ceramic Materials

Within the framework of the concept used, it is assumed that the destruction of ceramics due to thermal shock is initiated from defects in its structure, i.e., stress concentrators. In this case, the heat resistance of ceramics can be determined using the Weibull theory. For this purpose, a statistically significant sample of alumina ceramic samples was subjected to thermal shock. After that, the sample was mechanically tested and the Weibull parameters of the material were calculated (threshold stress, below which the probability of failure is zero; average strength value; limiting stress, above which the probability of failure is 100%; Weibull modulus). The degree of change of these parameters, in comparison with their values for sampling specimens before the thermal shock, served as an indicator of the thermal shock resistance. This indicator can be considered as a characteristic that determines the resistance of the ceramic structure to the initiation of thermal cracks on existing stress concentrators. The results of determining the thermal stability of alumina samples using the Weibull statistical theory were confirmed by the results of determining their thermal stability by the local thermal shock (LT) method.