Porous β-SiAlON Ceramic with Closed Packed Macropore

Abstract

Porous β-SiAlON ceramics are synthesized by reaction bonded method using hollow alumina spheres (HASs) as both sintering aids and pore-forming agents. Both micropores and macropores, which are constructured by SiAlON grains with different morphologies, are formed in the final SiAlON samples. The micropores are three-dimentional, and are built by equiaxial grains. While the hollow macropores, which have the similar morphology to hollow alumina sphere, are packed by elongated grains. In the sintering process, the solid dissolution process takes place, giving rise to the different alumina concentration of liquid phase, and thus resulting in the formation of two kinds of grains, the equiaxial grain and the elongated grain.

Keywords:

• Alumina
• Ceramic
• Grain
• Nitride
• Porosity
• Reaction
• Silicon
• Sintering

ACKNOWLEDGMENTS

This work was supported by the National Natural Science Foundation of China (90816018) and Xi'an Science and Technology Program (CXY08006(1)).