SYNTHESES OF NITRIDE AND CARBIDE CERAMICS FROM INTERCALATION COMPOUNDS BY CARBOTHERMAL REDUCTION.

To establish a new method for the carbothermal reduction process, the conversion of the montmorillonite-polyacrylonitrile (PAN) intercalation compound to nitride and carbide ceramics was studied. In the case of Ar atmosphere, the formation of SiC was observed above 1200 degree C. alpha -SiC was detected above 1300 degree C, while beta -SiC was formed above 1200 degree C. As oxides, Mg-Al-O compound was detected above 1300 degree C. On the other hand, the formation of beta -sialon and SiC was observed by the treatment in N//2 atmosphere above 1200 degree C. AlN was also detected above 1300 degree C. In these processes, the reaction route became unique because of preventing the crystallization of oxides. This fact was ascribed to the presence of PAN in the interlayer space.