Electroplating means that in a solution containing a metal ion to be plated, a plated layer can be obtained on the surface of the substrate by electrolysis, using the material or article to be plated as a cathode. In the electrolysis process, a chemical reaction occurs at the interface between the electrode and the electrolyte, the anode releases electrons to undergo oxidation reaction, and the cathode absorbs electrons to undergo reduction reaction. Electroplating can coat a material or article with a coating that is relatively uniform and has a good bonding force, so as to change its surface characteristics and appearance and achieve the purpose of material protection or decoration. Electroplating requires direct current (low voltage, high current), and can be used to corrosion coating zinc, cadmium, copper, nickel and other metals or zinc-nickel, nickel-tin, nickel-copper, copper-zinc and other alloys, according to the plating and matrix metal forming electricity Even when the electrode potential is different, it can be divided into two kinds of anode coating and cathode coating. In the corrosive medium, the potential of the anodized coating is more negative than that of the base metal. For example, zinc or cadmium is applied to the steel. When the coating is damaged, the coating will be dissolved as an anode, and the steel will have electrochemical protection, that is, “sacrificial” protection. The thicker the coating, the greater the protection The potential of the cathode coating is more positive than that of the base metal. For example, aluminum, copper, and nickel are coated on the steel. When the coating is damaged, the coating accelerates the corrosion of the exposed portion of the base metal, and can be protected only when completely impervious. Therefore, the coating should pay attention to its tightness and no damage, while the protective capacity determines its porosity, low porosity, and a large protective effect. Its anti-corrosion effect is to use the coating to isolate the external environment, so that the corrosive medium cannot penetrate into the base metal
