Abstract: Porous aluminium titanate (AT) composites were fabricated by sintering with γ-AlOOH, TiO₂ and SiC as raw materials. Effects of the particle size and the content of SiC on phases, microstructures, compressive strength, porosity and pore size distribution of products were investigated. Results show that the phases of the products are composed of Al₂TiO₅(AT), Al₆Si₂O₁₃, TiC, SiO₂, Al₂O₃ and a small amount of unreacted TiO₂. When SiC is added into γ-AlOOH and TiO₂ mixture, it reacts with TiO₂ and forms TiC and SiO₂. The small TiC particles distribute and disperse in the walls and shelves of porous products. Moreover, SiO₂ reacts with Al₂O₃, decomposted from γ-AlOOH, to form Al₆Si₂O₁₃ whiskers which distribute crisscross between Al₂TiO₅ grains or in the pores. The Al₆Si₂O₁₃ whiskers along with TiC particles contribute greatly to improving the compressive strength of the products, particularly with small SiC particles. When SiC particles are big, the packing patterns of powder mixtures are changed and the porosities of the products are increased. However, when SiC content is beyond 5wt%, both the porosities and compressive strength of the products decrease due to the formation of more low-melting point SiO₂, and some SiO₂ fills in the pores of the porous products, and some exists on the surface of Al₂TiO₅ grains and weakens the bonding strength.

Key words: porous materials, Al₂TiO₅, reaction sintering, Al₆Si₂O₁₃ whiskers