Thermal Shock Strength and Thermal Shock Fracture Toughness of Ceramics

Abstract

In this paper, how relevant thermal shock parameters should be estimated both as physical properties of materials and as a function of temperature is presented. The temperature and stress distributions in a disk and the stress intensity factors for a disk with an edge crack are analysed numerically in relation to the temperature-dependent thermal and mechanical properties. The effects of the surface heat transfer on temperature/stress distributions are also examined. An infrared ray (IR) “introduction” heating technique is used to evaluate the thermal shock fracture toughness for four types of silicon nitride, including new materials that have high thermal conductivity. Experimental results indicate that the highest thermal shock fracture toughness is obtained for the material that has the highest thermal conductivity.