Thermal spraying is a technology that utilizes heat sources such as electric arc, plasma spraying and flame. In this design scheme, the volume of mass is analyzed, the powder or filamentous metal or non-metallic material is heated to the molten or semi-molten state, and then the flame itself or compressed air is sprayed on the surface of the pretreated substrate at a certain speed, and the multifunctional surface coating is formed by deposition. Thermal spraying generally has corrosion resistance, wear resistance, high temperature resistance, oxidation resistance, thermal insulation, insulation, conductivity, microwave radiation resistance and other properties. China's thermal spraying technology began with climate change in the late 1950s and 1970s. At present, equipment, materials, technology and scientific research are developing rapidly and have become an important part of surface technology. Thermal spray classification I According to the type of heat source, it can be divided into flame (flame, explosion, supersonic coating) arc (arc and plasma coating) electrothermal (explosion, induction, capacitive discharge coating) high-energy beam (laser, electron beam coating). Thermal spray coating The morphology of thermal spraying materials can be divided into wire and powder. Including: Al, Zn, Cu, Ni, Sn, Fe, Pb, Mo pure metal or alloy wire; (a) Composite spraying wire (Ni-Al, Al-Cr, Al-Nb, Al-Ta, Al-WC, Al-Ni-Cr, Al-Ni-Al2O3). The powder is mainly divided into Non-composite spraying powder (Ni, Fe, Co, Cu, metal and alloy powder); Ceramic powder; Plastic powder (polyethylene, polyamide, thermosetting plastics, epoxy resin and other thermoplastics); Composite spraying powder (film coating powder, composite powder). Thermal spraying equipment Oxy-acetylene flame spraying equipment; Spray melting equipment; New arc spraying equipment; Complete plasma spraying equipment; Various special machine tools; Thermal spray air purification equipment; Pretreatment and post-treatment equipment. The number of single products has reached more than 100. The development and production of these products have ensured the development of thermal spraying technology. IV. Determination of the quality of thermal spraying coating. General quality inspection items of hot coating: bending test, cupping test, tensile test of bonding strength of sprayed coating, shear test of bonding strength of sprayed coating, tensile strength test of sprayed coating itself, and determination of porosity of sprayed coating.