Thermal Shock Behavior of Isotropic and Anisotropic Porous Silicon Nitride

Abstract

The thermal shock behavior of isotropic and anisotropic porous Si 3 N 4 was evaluated using the water‐quenching technique. The critical temperature difference for crack initiation was found to be strongly dependent on the ratio of fracture strength to elastic modulus. Because of a very high strain‐to‐failure, anisotropic porous Si 3 N 4 showed no macroscopic cracks and was able to retain its strength even at a quenching‐temperature difference of ∼1400°C.