Preparation of Silicon Carbide/Aluminum Nitride Ceramics Using Organometallic Precursors

Abstract

Solid solutions of 2H ‐SiC/AlN can be prepared at temperatures less than 1600°C by rapid pyrolysis (“hot drop”) of mixtures of [(Me 3 Si) 0.80 ((CH 2 =CH)MeSi) 1.0 (MeHSi) 0.35 ] n (VPS) or [MeHSiCH 2 ] n (MPCS) with [R 2 AlNH 2 ] 3 , where R=Et, i ‐Bu or simply by slow pyrolysis of the precursor mixture in the case of [Et 2 AlNH 2 ] 3 . In contrast, slow pyrolysis of mixtures of VPS or MPCS with [ i ‐Bu 2 AlNH 2 ] 3 yields a composite of 2 H ‐AlN and 3 C ‐SiC at 1600°C, which transforms into a single 2 H ‐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.