PREPARATION OF SILICON-CARBIDE ALUMINUM NITRIDE CERAMICS USING ORGANOMETALLIC PRECURSORS

Solid solutions of 2H‐SiC/AlN can be prepared at temperatures less than 1600°C by rapid pyrolysis (“hot drop”) of mixtures of [(Me3Si)0.80((CH2=CH)MeSi)1.0(MeHSi)0.35]n (VPS) or [MeHSiCH2]n (MPCS) with [R2AlNH2]3, where R=Et, i‐Bu or simply by slow pyrolysis of the precursor mixture in the case of [Et2AlNH2]3. In contrast, slow pyrolysis of mixtures of VPS or MPCS with [i‐Bu2AlNH2]3 yields a composite of 2H‐AlN and 3C‐SiC at 1600°C, which transforms into a single 2H‐SiC/AlN solid solution on heating to 2000°C. The influences of the nature of the precursor and processing conditions on the structure, composition, and purity of the SiC/AlN materials are discussed. Copyright © 1990, Wiley Blackwell. All rights reserved