What is Silicon Carbide?

What is Silicon Carbide

Silicon carbide is a non-metallic carbide composed of silicon and carbon elements covalently bonded, and its hardness is second only to diamond and boron carbide. The chemical formula is SiC. Colorless crystals, blue-black in appearance when oxidized or containing impurities. The silicon carbide variant with a diamond structure is commonly known as emery. The hardness of emery is close to that of diamond, and its thermal stability is good. At 2127 ℃, it is converted from β-silicon carbide to α-silicon carbide, and α-silicon carbide is still stable at 2400 ℃. It is stable to hydrofluoric acid aqueous solution and concentrated sulfuric acid, but not stable to mixed acid of concentrated hydrofluoric acid and nitric acid or phosphoric acid. Decomposed by molten alkali in an air atmosphere. It is divided into synthetic silicon carbide and natural silicon carbide. Natural silicon carbide is called moissanite, which mainly occurs in kimberlite and volcanic amphibole, but its amount is very small and has no mining value.