2. Ceramic coating refers to the coating material used for ceramic spraying. The main components of ceramics are silica, alumina, sodium oxide, calcium oxide, magnesium oxide, titanium oxide and so on. Ceramic coating is an inorganic protective layer or film covering the surface of the substrate. It can change the morphology, structure and chemical composition of the substrate surface and endow the substrate with new properties, such as wear resistance, corrosion resistance, anti-sticking, high hardness, high temperature resistance and insulation.