Synthesis of α-SiC(6H) using 6H polytype SiC diluent by the seeding technique

The feasibility of α-SiC(6H) polytype synthesizing from the SiO2 + 2Mg + C mixture by a traditional combustion synthesis process is demonstrated using an iterative method, called the seeding technique. Using this method the effect of an addition of commercial α-SiC(6H) powder on the SiO2 + 2Mg + C combustion synthesis system was investigated. The formation of α-SiC(6H) polytype in the reaction products has been confirmed by X-ray diffraction technique. The optimal conditions to obtain phase pure α-SiC(6H) having crystalline shape and a size about 0.5–1 µm have been demonstrated through the seeding technique.

Combustion synthesis of α-SiC powder from SiO2 + 2Mg + C mixture with the addition of commercial α-SiC(6H) powder was carried out. The addition of α-SiC(6H) as seed crystals promoted SiC(6H) polytype formation, that has been confirmed by X-ray diffraction technique. α-SiC(6H) submicrometer size powder was obtained, when the concentration SiC(6H) seed crystals was about 0.8–1 mol.Figure optionsDownload as PowerPoint slide