In the manufacturing process of gear reducers, electroplating technology is used.Electroplating is the process of plating a thin layer of other metals or alloys on the surface of certain metals using the principle of electrolysis. It is the process of using electrolysis to attach a layer of metal film to the surface of metal or other materials to prevent corrosion and improve Abrasion resistance, conductivity, reflectivity, and enhance aesthetics.The common electroplating of gear reducer is galvanized, tinned and nickel-plated. The text gives a detailed introduction to these three common electroplating methods.
(1) Zinc plating, zinc is a silver-white metal, in dry air. The surface hardly changes, but in humid air or water containing carbonic acid gas (such as carbon dioxide), zinc will oxidize and the inkstone will be covered with a layer of alkali Carbonate film, which can protect zinc from continued corrosion.The galvanized layer is of medium strength and can be bent, but it is not suitable for compression and has poor wear resistance.Galvanizing on the surface of steel parts is a typical anode coating widely used, which is suitable for the protection of ferrous metal parts, such as the housing, base, bolts, nuts, etc. of some motors.In order to improve the protective ability of the zinc coating, the parts after the zinc coating can be immersed in a chromic acid or chromate solution to form a stable chromate passivation film on the surface of the zinc coating.Passivation treatment after galvanizing, corrosion resistance is very strong.The thickness of the galvanized layer can be determined according to the requirements of the parts, generally 7-35 microns.
(2) Tin-plated, the tweezers are plastic and malleable silver-white metal 1 Fu has higher stability than zinc, and the plating layer is more beautiful than the galvanized layer.The plating layer will gradually form an oxide film, which is tighter than the plating layer.However, the steel tin is a cathodic coating, so it is not as good as the protective performance of the molybdenum zinc.The pan plating can also be passivated to improve protection.The chemical stability of dry-fu coating is better than that of zinc coating, so it is more suitable for use in humid atmosphere, marine atmosphere and high-temperature atmosphere.The saw coating can be thinner than the zinc coating.
(3) Nickel plating. Nickel is also a relatively stable white metal with excellent corrosion resistance. Therefore, the nickel plating layer can resist corrosion by the atmosphere, alkali and certain acids.The nickel plating layer has a fine grain structure, has a high finish after polishing, and has the functions of protection and decoration.Both steel and key parts can be used, especially copper and its alloy parts, which are coated with a thin layer. That is anti-corrosion and beautiful. The nickel plating of steel parts is a cathodic coating. When there are more pores in the coating, it will accelerate Attention should be paid to the corrosion process during use.The hardness of the nickel-plated layer is lower than that of the dry chromium-plated layer, but it is also close to the hardness of hardened steel.The coating thickness is also 7-30 microns.
