Thermo-mechanical behavior of reticulated alumina foam ceramics and the influence of structure characteristics

This study explores the thermo-mechanical behavior of reticulated alumina foam ceramics and the influence of structural characteristics. Industrial and laboratory specimens with varied ppi-numbers and strut thickness were used, the latter prepared via two coating processes to introduce inner/outer layer inhomogeneity. Cylindrical splitting tests revealed that increases in foam weight and strut thickness enhance mechanical strength, while inhomogeneity reduces load-bearing capacity due to uneven stress distribution. Heavier foams showed more concentrated cracking and energy release. The inner/outer homogeneity gradient provided structural support, reducing early energy dissipation. High-temperature tests, including creep and refractoriness under load, showed that composition differences affected softening behavior, with high-ppi foams exhibiting better pressure transfer and creep resistance. Inhomogeneity had limited impact on softening resistance. This study can offer theoretical guidance for optimizing structure and fabrication of ceramic foam filters. • Tensile and softening failures of porous ceramics studied via splitting test and creep test. • Correlation revealed between strut damage and macroscopic ceramic fracture. • ppi-number and coating homogeneity significantly affect thermo-mechanical behavior. • Dip-centrifugation and spraying methods yield different foam homogeneity levels. • Structural insights provide guidance for optimizing ceramic foam filter performance.