Abstract In spite of the extensive use of porous ceramic materials in high-temperature applications, there are very few experimental and no theoretical studies on analyzing their temperature-dependent fracture behavior. In this work, in order to fill this research gap, a novel theoretical model for the characterization of fracture strength of porous ceramic materials with respect to temperature is proposed. The model considers the effects of the Young's modulus, specific heat capacity, volume fraction of pores, sizes of pore and flaw (critical flaw size). Further, through simplification the model can be used for the characterization of the strength of the dense ceramic materials. The models are verified by the obtained excellent agreements between the predictions and measurements. The experimentally observed phenomena are analyzed and explained according to the predicted results. Our analysis indicates that the temperature dependence of the fracture strength of the porous ceramic materials in vacuum is controlled by the Young's modulus and volume fraction of pores. While on high temperature oxidation the critical flaw size with respect to temperature should be considered. Furthermore, the temperature dependence of the strength of the dense ceramics is governed by the Young's modulus.

中文翻译：

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多孔陶瓷材料断裂强度的温度依赖性

摘要 尽管多孔陶瓷材料在高温应用中得到了广泛的应用，但很少有实验研究和理论研究来分析其随温度变化的断裂行为。在这项工作中，为了填补这一研究空白，提出了一种新的理论模型，用于表征多孔陶瓷材料的断裂强度随温度的变化。该模型考虑了杨氏模量、比热容、孔隙体积分数、孔隙和缺陷尺寸（临界缺陷尺寸）的影响。此外，通过简化该模型可用于表征致密陶瓷材料的强度。这些模型通过预测和测量之间获得的极好的一致性得到验证。根据预测结果对实验观察到的现象进行分析和解释。我们的分析表明，多孔陶瓷材料在真空中的断裂强度的温度依赖性受杨氏模量和孔隙体积分数的控制。在高温氧化时，应考虑与温度相关的临界缺陷尺寸。此外，致密陶瓷强度的温度依赖性受杨氏模量控制。