Fabrication and microstructures characterization of AlN-Al2O3 porous ceramic by nitridation of Al4O4C

An innovative approach was developed for the fabrication of AlN-Al 2 O 3 porous ceramic by heat-treating Al 4 O 4 C porous ceramic under a flowing nitrogen atmosphere. The effects of sintering temperature on phase and microstructural evolution changes were investigated. The results indicated that phase evolution of the nitridation of Al 4 O 4 C porous ceramics was significantly different from dense Al 4 O 4 C ceramics. AlN-Al 2 O 3 porous ceramic produced using this new method had a homogeneous local chemical composition with the two phases tightly combined in the composite material. Possible reaction mechanisms for the fabrication of AlN-Al 2 O 3 porous ceramic are discussed by considering reactions at the initial and later stages during the nitridation process.