Fracture energy of mullite ceramic heat storage material under thermal shock conditions

Abstract

Based on an engineering application background of mullite ceramic regenerative materials, the fracture energy of mullite ceramic materials was tested using a three point bending experiment combined with the method of rupture work under thermal shock conditions. The variations of fracture energy, along with temperature changes and the depth of crack as well as their relationship with fracture toughness and energy release rate, were discussed in this paper. The results indicated that fracture energy and the depth of crack have a linear relationship. Within the scope of the studied temperature (800°C), the fracture energy reached a higher value at ΔT 400°C and a lower value at ΔT 600°C. With the temperature variations, the fracture toughness, fracture energy and energy release rate follow the same law, and the energy release rate of the ceramic was about 30–45% of the fracture energy.