How is silicon carbide classified according to its crystal structure?
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.