Specimens of heated alumina foams were thermally shocked by immersion in water or oil. Two distinct temperature profiles were found to exist during liquid quenching: a macroscopic gradient due to heating of the fluid during infiltration into the foam and a microscopic gradient across each individual strut. Thermal stresses were calculated using a semi-empirical, finite element model. The peak thermal stresses were coupled with the two-parameter Weibull distribution of the strut strengths to calculate the probability of crack extension on a strut for eight cellular geometries. Experimentally, the thermal shock resistance increased with increasing relative density and increasing cell size. The predicted critical temperature differences were in fair agreement with measured values.
Email your librarian or administrator to recommend adding this journal to your organisation's collection.