关键词: 抗热震性, 临界温差, 瞬态热应力, 瞬态温度场, 陶瓷材料

Abstract: Based on the critical stress fracture theory for ceramic materials, the thermal shock behaviors of ceramic components with different shapes are investigated by means of the calculations of transient temperature fields and transient thermal stresses for infinite plate-, infinite cylinder- and ball-shaped components under the convective boundary conditions respectively, according to which the formulae of critical temperature difference leading to the critical stress at the surface as thermal shock resistance parameters for these three shapes were obtained respectively. The calculation results reveal that the dimensionless time for the surface to attain the critical thermal stress for infinite plate is the longest, infinite cylinder takes the second place, while the dimensionless time for the surface to attain the critical thermal stress for ball is the shortest in case of the same Biot numbers. The critical temperature difference for ceramic ball is the highest, I.e. the thermal shock resistance is the highest, infinite cylinder takes the second place, whereas the thermal shock resistance of infinite plate is the lowest.

Key words: Ceramic materials, Critical temperature difference, Thermal shock resistance, Transient temperature field, Transient thermal stress