In terms of advanced ceramics, factors as compactness, grain growth, inter-crystalline formation and pore size change are involved in the sintering process.

Joining of advanced ceramics in green state has become an attractive part of ceramics research because it provides a possibility of obtaining complex-shaped ceramic parts,which are not possible or not cost-effective by existing technique.

Microstructural features of advanced ceramics(silicon nitride, silicon carbide, alumina, and alumina silicon carbide nano composite)have been reviewed with emphasis being placed on the relationship between microstructure and properties.

In-situ reactive synthesis of advanced ceramics;

Joining of reaction-bonded silicon carbide (RBSiC) to itself has been realized using a preceramic polymer, polysiloxane, as joining material.

Perhydropolysilazane(PHPS) and polyhydridomethylsilazane(PHMS) were used as preceramic polymers,respectively,to prepare three-dimensional silica fiber reinforced silicon nitride composites through repeated infiltration and pyrolysis at a low temperature(600℃),and the mechanical properties and microstructures of the composites were investigated through comparison.

A novel soluble preceramic polymer to SiBNC ceramic, polyborosilazane (PBSZ), was synthe-sized via a cocondensation approach with a yield of about 91% (w%) by using dichloromethylsilane (MeHSiCl2), boron trichloride (BCl3) and hexamethydisilazane (HMDZ) as the starting materials.