Thermo-mechanical damage of Al2O3-C reticulated porous ceramic and effect of functional coatings

Thermo-mechanical performance of carbon-bonded alumina filters is essential for guaranteeing their structural stability and filtration capability. This work investigates the Mode I fracture of Al 2 O 3 -C porous ceramic as well as the influence of reticulate structure and coatings (alumina and carbon-bonded calcium hexaluminate). The cylindrical splitting test is validated for evaluating the strength of foam and individual strut. DIC and AE techniques were applied to monitor tensile failure induced by compressive loading . The results showed central crack propagation and continuous AE signal release caused by localized damage. Generally, the mechanical strength increases with pore density and the application of alumina coating. This improvement results from more continuous stress transmission and better sintered struts. However, calcium hexaluminate coating is less effective for strengthening foams at room temperature. Both functional coatings and the continuity of reticulate foams show positive effect on the deformation resistance to temperature and load.