structure of silicon carbide
Pure silicon carbide is a colorless and transparent crystal. Industrial silicon carbide is light yellow, green, blue or even black due to the type and content of impurities, and its transparency varies with its purity. The crystal structure of silicon carbide is divided into hexagonal or rhombohedral α-SiC and cubic β-SiC (called cubic silicon carbide). α-SiC forms many different variants due to the different stacking sequences of carbon and silicon atoms in its crystal structure, and more than 70 kinds have been found. β-SiC transforms into α-SiC above 2100°C. The industrial manufacturing method of silicon carbide is to use high-quality quartz sand and petroleum coke to be refined in a resistance furnace. The refined silicon carbide blocks are crushed, acid-base washed, magnetic separation and sieving or water separation to produce various particle sizes.
