By adopting advanced repair technology, strict product quality control and accurate cost accounting, remanufacturing engineering can reuse used products and achieve good technical and economic indicators. Remanufacturing engineering aims at high quality, high quality, energy saving, material saving and environmental protection, which is in line with the national sustainable development strategy. Remanufacturing engineering is based on advanced maintenance technology, among which thermal spraying technology is widely used in remanufacturing because of its process flexibility, controllable coating quality and cost advantage. According to the principle of thermal spraying, the pre-deposition state of particles determines the performance of the coating, including the velocity of particles, the temperature of particles and the melting state of particles. The velocity of the particles plays an important role on the performance of the coating, when particles hit substrate surface, high speed can form big impulse, particle deformation ability is strong, beneficial to the improvement of the coating binding force and the density, excellent supersonic spray coating performance thanks to high particle velocity, in recent years the research of hot, cold spraying technology, The coating is deposited by the kinetic energy of high-speed particles. According to the principle of air dynamics and rocket engine, the supersonic arc spraying technology (HVAS) and multi-function supersonic supersonic flame spraying technology (HVO/AF) have been successfully developed, which can produce high performance metal, alloy, metallic ceramic and oxide free metal coating, and has been widely used in industry.
Arc spraying has the advantages of high production efficiency, low production cost and small heating of the workpiece. It should be widely used in the long-term anti-corrosion and wear-resistant coating, which plays an important role in thermal spraying. However, compared with plasma spraying and supersonic flame spraying, the coating quality of ordinary arc spraying is lower, and the bonding strength is about 20 MPa. The pore gap ratio is 3 %-10 %, which limits the application of arc spraying. Super sound velocity arc spraying technology to improve the speed of particles as a starting point, mining With laval nozzle so as to improve the effect of the spray gun, enhances the flow of particle acceleration, the velocity of the particles was raised to the ultra sonic, preparation of coating combined with high strength and low porosity, low surface roughness, compared with common arc spraying, The coating quality has been improved to a great extent, close to the level of plasma spraying, the arc spraying coating quality has been improved.
The principle of supersonic arc spraying is that the arc burning at the end of the wire will melt the evenly sent wire, and the supersonic air flow after the laval nozzle is accelerated will atomize the melted wire into fine particles with uniform distribution, which spray to the workpiece to form a coating. Like general electric arc spraying, the supersonic electric arc spraying is a repeated into the process of melting, atomizing, deposition, but in the mode of atomization, the supersonic electric arc spraying is different with ordinary electric arc spraying, general electric arc spraying using subsonic atomization, the supersonic electric arc spraying using supersonic atomization, uniform atomization particles in small, high speed, Favorable for obtaining high quality coating.
The supersonic arc spraying coating has high bonding strength, low porosity, low surface roughness, good wear and corrosion resistance, and has a wide application prospect in industry, especially in the field of long-term anti-corrosion and wear resistance coating. Supersonic arc spraying technology is flexible, excellent performance coating can be obtained in a considerable range of process parameters, after the successful development of the equipment, has been widely used.
