Brief Analysis on Application of Thermal Spray Ceramic Coating Technology

       The widely used thermal spraying techniques include flame spraying, arc spraying, plasma spraying, explosive spraying and supersonic spraying. Flame spraying is achieved by a flame spray gun that introduces acetylene, oxygen or compression through a gas valve, respectively.



Thermal spraying technology is widely used in flame spraying, arc spraying, plasma spraying, explosive spraying and supersonic spraying technology. The flame spraying is realized by a flame spray gun. The spray gun introduces acetylene, oxygen or compressed air respectively through the air 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, the mist-like droplets are formed and sprayed onto the surface of the substrate to form a coating. The two wire-shaped material coating materials used in arc spraying are automatically introduced by the wire feeder. When a large current is passed between the two wire-shaped materials, an arc will be generated, and the wire-shaped material will melt rapidly under the high temperature of the arc, and is compressed The air acts as small droplets that are 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 material science. It is a technology of surface strengthening and surface modification. By spraying a 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, wear reduction and sealing properties. Thermal spraying technology is mainly used for pre-protection of high-temperature, wear-resistant, corrosion-resistant components, preparation of functional coatings, and repair of failed components.



Most ceramic materials have ionic bond or covalent bond structure, high bond energy, strong interatomic bonding force, and low surface free energy, which endow ceramic materials with high melting point, high stiffness, high chemical stability, high insulation and thermal insulation ability, thermal expansion However, compared with metal materials, its plastic deformation ability is poor, and it is sensitive to stress concentration and cracks. Obviously, using ceramics as a mechanical structural material is less reliable than metal materials, and it is difficult to machine and cost high. However, the use of thermal spraying technology to prepare ceramic coatings on metal substrates can organically combine the characteristics of metal materials and ceramic materials to obtain composite material structures. Due to the exceptionally superior comprehensive properties of this composite material structure, thermal spraying technology has rapidly expanded from high-end fields to civil industries such as energy, transportation, metallurgy, light textiles, petrochemicals, 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, toughness and ease of processing of metal materials with the high temperature resistance, wear resistance and corrosion resistance of ceramic materials. and other characteristics combined. 2. Reasonable selection of coating materials and suitable spraying process can obtain surface strengthening coatings with various functions. 3. Not limited by the matrix: The matrix 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, paper, etc. 4. Not limited by workpiece size and construction site. 5. The coating deposition rate is fast, the thickness is controllable, and the process is simple. 6. The machinability of the ceramic coating is good, and it can be sprayed after the coating is damaged.