Brief Analysis on the Application of Thermal Spraying Ceramic Coating Technology

       In the thermal spraying process, flame spraying, arc spraying, plasma spraying, explosive spraying and supersonic spraying technology are widely used. Flame spraying is realized by a flame spray gun, which introduces acetylene, oxygen or compression through a gas valve.



Thermal spraying technology is widely used in flame spraying, arc spraying, plasma spraying, explosive spraying and supersonic spraying technology. Flame spraying is realized by a flame spray gun. The spray gun introduces acetylene, oxygen or compressed air through the gas valve. After the acetylene and oxygen are mixed, a combustion flame is generated at the nozzle outlet. The introduced powder or rod coating material is heated and melted in the flame. , Under the action of the flame flow, the mist-like droplets are sprayed onto the surface of the substrate to form a coating. The two wire-shaped materials used in arc spraying are automatically introduced by the wire feed wheel. When a large current passes between the two wire-shaped materials, an electric arc will be generated. The air acts as small droplets and is sprayed onto the surface of the substrate to form a coating.



Thermal spraying technology is an important part of surface engineering in the field of materials science. It is a surface strengthening and surface modification technology. By spraying a layer of coating on the surface of the metal substrate, the metal has wear resistance, corrosion resistance and high temperature resistance. Oxidation, electrical insulation, heat insulation, radiation protection, anti-wear and sealing properties. Thermal spraying technology is mainly used for the pre-protection of high-temperature, wear-resistant, and corrosion-resistant components, the preparation of functional coatings, and the repair of failed components.



Most ceramic materials have ionic bond or covalent bond structure, high bond energy, strong bonding force between atoms, and low surface free energy, which endows the ceramic material with high melting point, high stiffness, high chemical stability, high insulation and heat insulation capacity, and thermal expansion Small coefficient, small friction coefficient and other characteristics; but compared with metal materials, its plastic deformation ability is poor, and it is sensitive to stress concentration and cracks. Obviously, using ceramics as mechanical structural materials has worse reliability than metal materials, difficult machining, and high cost. However, the use of thermal spraying technology to prepare ceramic coatings on the metal substrate can organically combine the characteristics of the metal material with the characteristics of the ceramic material to obtain a composite material structure. Due to the exceptionally superior comprehensive performance of this composite material structure, thermal spraying technology has rapidly expanded its application from high-end fields to civil industrial fields such as energy, transportation, metallurgy, textile, petrochemical, and machinery.



The characteristics of ceramic coating technology Compared with the overall structure of ceramic materials, ceramic coating technology has the following characteristics: 1. It can organically combine the strength and toughness and ease of processing of metal materials and the high temperature resistance, wear resistance and corrosion resistance of ceramic materials. And other characteristics. 2. Reasonable selection of coating materials and appropriate spraying process can obtain various functional surface strengthening coatings. 3. Not limited by the substrate: The substrate material used for thermal spraying can be inorganic materials such as metal, ceramics, cement, refractory materials, stone, gypsum, etc., or organic materials such as plastic, rubber, wood, and paper. 4. It is not restricted by the size of the workpiece and the construction site. 5. The coating deposition rate is fast, the thickness is controllable, and the process is simple. 6. The ceramic coating has good machinability, and spraying can be carried out after the coating is damaged.