Preparation of A1 4 SiC 4 by Solid-State Reaction

In this paper, Al4SiC4 was synthesized by using flint, aluminum and carbon black as raw materials, and they mass ratio was 28:50:22. The samples were fired at 1500 degrees C, 1600 degrees C and 1700 degrees C in an argon atmosphere. The phase compositions were determined by X-ray diffraction (XRD), the microstructures were examined by scanning electron microscope (SEM) and the elemental and quantitative compositions were determined by the energy dispersive X-ray spectroscopy (EDX). The results showed that the flint reacted with the carbon black, and produced Al2O3 and SiC firstly; meanwhile Al4C3 as intermediate product formed by the reaction between Al and C. Then a certain Al4C3 reacted with SiC, and produced Al4SiC4; most Al4C3 reacted with the Al2O3, and produced Al4O4C at higher temperature. Subsequently, the Al4O4C and the SiC reacted with carbon black, and produced Al4SiC4. The formed quantity of Al4SiC4 increased as the heating temperature was raised, and crystal structure was the flake structure of 1-2 mu m thickness and about 10 mu m length. The formation mechanism of Al4SiC4 was also discussed.