Effects of heating temperature on the fracture toughness of macroporous alumina supports added Al powder

An amount of Al powder was added to toughen Al₂O₃ porous supports by dry press forming. Based on the toughening mechanism of Al₂O₃/Al composite, the effects of heating temperature on the fracture toughness and bending strength of macroporous Al₂O₃/Al supports were investigated in detail, and the microstructure of specimens made of the supports was analyzed by SEM. The results show that the fracture toughness of the supports is influenced by calcining temperature. When the calcining temperature is low, unoxidized Al phase can absorb amount of fracture energy to make the fracture toughness of the supports high. But when the temperature is above 1200℃, the cracks which is occurred in the oxidation processing of Al phase can improve the fracture toughness of the supports, and the contribution of cracks is more important than the amount of Al phase to the fracture toughness of supports.