ABSTRACT Porous silicon carbide ceramics were prepared by an in situ reaction bonding process using clay and alumina as additives. The effects of alumina additive, pore former on phase composition, microstructure, flexural strength and thermal shock resistance of the ceramics were studied. Thermal shock resistance of porous SiC ceramics due to cooling was evaluated as a function of quenching temperatures and quenching cycles using water- and air-quenching technique. It was observed that residual strength of the quenched samples in water decreased with increase in the quenching temperature but was almost independent of quenching cycles. In water quenching, the surface of the sample cooled almost instantly but the inside remained hot which created an uneven thermal profile and generated microcracks in the sample; as a result sudden reduction of flexural strength was observed. The results showed that flexural strength and thermal shock resistance properties of the ceramics prepared with alumina are better than those of the ceramics prepared without alumina and the material was found suitable for hot gas filtration application. GRAPHICAL ABSTRACT

中文翻译：

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以粘土和氧化铝为添加剂制备的多孔碳化硅陶瓷的抗热震性

摘要 采用粘土和氧化铝作为添加剂，通过原位反应键合工艺制备多孔碳化硅陶瓷。研究了氧化铝添加剂、成孔剂对陶瓷的相组成、微观结构、弯曲强度和抗热震性的影响。使用水和空气淬火技术，根据淬火温度和淬火周期来评估多孔 SiC 陶瓷因冷却而产生的抗热震性。据观察，淬火样品在水中的残余强度随着淬火温度的升高而降低，但几乎与淬火循环无关。在水淬过程中，样品表面几乎立即冷却，但内部仍然很热，导致热分布不均匀并在样品中产生微裂纹；结果，观察到弯曲强度突然降低。结果表明，用氧化铝制备的陶瓷的抗弯强度和抗热震性能优于未用氧化铝制备的陶瓷，适合热气过滤应用。图形概要