What is high-speed arc spraying? What are the advantages? field of application

       High-speed arc spraying adopts Laval nozzle and computer-aided design on the basis of ordinary arc spraying, optimizes the design of spray gun, increases the speed of sprayed particles to subsonic speed, changes the atomization effect of particles, and improves the coating quality . High-speed arc spraying improves the atomization effect, enhances the acceleration effect of airflow on particles, and produces high-temperature, high-speed, uniform and fine jet particle jets. The resulting coatings have high bonding strength, low porosity, and low surface roughness. Compared with ordinary arc spraying, the coating quality and spraying efficiency are higher, which makes the arc spraying technology rise to a new stage.



    On the basis of ordinary arc spraying, the Armored Forces Engineering College optimized the structure of the traditional arc spray gun according to the principle of aerodynamics, and successfully developed the HAS-01 high-return arc spray gun. The speed of the particles is close to 300m/s, the porosity is below 3%, and the bonding strength is above 40MPa. The bonding strength and porosity of the sprayed layer are better than ordinary arc spraying.

    High-speed arc spraying technology can not only be used for the repair of wear-resistant parts, but also has been more and more applied in the treatment of hot corrosion of boiler pipes. For example, when the connecting rod journal of a high-power diesel engine is severely strained, aluminum bronze is used as the bottom layer and 3Cr13 as the working layer, the crankshaft is repaired, and the specified dimensional accuracy is achieved by machining. High-speed arc spraying technology can also be used in large-area anti-corrosion, large-scale hydraulic press plunger, papermaking dryer, repair and manufacturing of bearing bushes, mold rapid prototyping, hull deck surface anti-skid, surface decoration and other fields.

    High-speed arc spraying has advantages:

    Compared with ordinary arc spraying and flame spraying, high-speed arc spraying has the following characteristics:

    (1) The bonding strength of the coating is significantly improved. When spraying stainless steel wire, the bonding strength between the coating and the substrate is as high as 50MPa. The bonding strength of ordinary arc spraying is generally 20MPa~40MPa, and the bonding strength of general flame spraying is less than 20MPa.

    (2) The internal porosity of the coating is low and the porosity is low. The porosity of ordinary arc spraying is 8%~15%, the porosity of flame spraying is generally greater than 6%, and the porosity of high-speed arc spraying is only 2%~3%.

    (3) The particle speed is increased, and the atomization effect is obviously improved. The atomized particle diameter of high-speed arc spraying is generally 15 μm (stainless steel), which is 3 to 7 times smaller than that of conventional arc spraying (generally 20 μm to 40 μm).

    (4) The inner structure of the coating is uniform and dense, and the surface roughness is not high. Due to the high-speed airflow atomization, high-temperature, high-speed, uniform and fine spray particles are generated, which are deposited on the surface of the substrate to form a dense and uniform coating.

    Which areas are mainly used in

    High-speed arc technology has a wide range of applications in the fields of anti-corrosion, repair and remanufacturing of mechanical products: it can be used for anti-corrosion treatment of ships, bridges, mine supports and equipment, boiler pipes, hot roll plungers, papermaking, dryers, mold repair: machinery Recovery of part size out of tolerance in manufacturing, surface strengthening of parts, special preparation of parts, and rapid manufacturing of molds: it can partially replace the electroplating process. Its application will produce great economic and social efficiency.