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, low 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 spray technology to prepare ceramic coatings on metal substrates can organically combine the characteristics of metal materials with those of ceramic materials to obtain a composite structure. Due to the exceptionally superior comprehensive performance of this composite material structure, the thermal spraying technology has rapidly expanded its application from high-end fields to civil industries 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 easy processing of metal materials with the high temperature resistance, wear resistance and corrosion resistance of ceramic materials.
2. Reasonable selection of coating materials and appropriate spraying process can obtain various functional surface strengthening coatings.
3. Not restricted 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, paper, etc.
4. Not limited 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 workability, and spraying can be carried out after the coating is damaged.
