High Temperature Reactions and Microstructures in the Al2O3-AlN System

摘要

The importance of the aluminum oxide/aluminum nitride composition join in the Silicon nitride/silicon dioxide/aluminum nitride/aluminum oxide system, especially in relation to the formation of sialons and the AIN polytype-like phases, has been well documented. Lejjus (1964), Gauckler and Petzow (1976) and Sakai (1978) have published various aspects of the apparent phase equilibria in this system, derived primarily by hot pressing and with minimal microstructural characterization. This paper will present a new interpretation of the phase equilibria in this system, with emphasis on the spinel phases and the AlN polytype-like phases. One of the spinel phases with a solid solubility composition range from 40 to 27 mole % AlN has been named ALON and can be relatively sintered to transparent polycrystalline bodies. This material can be though of as a nitrogen stabilized cubic aluminum oxide. New property data, such as mechanical, thermal shock and expansion, oxidation on air and dielectric, will be detailed in the paper.