Synthesis of AlN–SiC solid solution through nitriding combustion of Al–C–Si 3N 4 in air

Abstract

A simple way of fabricating AlN–SiC solid solutions (AlN–SiCss) through the combustion reaction of aluminum, carbon and Si 3N 4 powder mixtures in air is reported. X-ray diffraction analysis, scanning electron microscopy and energy dispersive spectroscopy are employed to analyze the phase composition and microstructure of the as-synthesized products. It is found that the phase composition of the product changes gradually with the increase in air infiltration distance, accompanied by variation in the partial pressure of N 2/O 2 at different locations of the powder compacts. Homogeneous single-phase AlN–SiCss powders with well-crystallized hexagonal morphologies and a fine particle size of 3 μm can be obtained within a suitable distance range of N 2 infiltration. Thermodynamic analysis of the Al–C–Si 3N 4–air combustion reaction system was conducted based on the N 2/O 2 diffusion kinetic model, and the calculated results are in good agreement with the experimental phenomenon.