Electroplating is the process of electroplating a thin layer of other metal or alloy on the surface of certain metals by electrolysis. It is a process of using electrolysis to attach a metal film to the surface of metal or other materials to prevent metal oxidation ( Such as rust), improve the wear resistance, electrical conductivity, reflective, anti-corrosion (copper sulfate, etc.) and enhance the appearance and other effects.

During electroplating, a plated metal or other insoluble material is used as an anode, and a workpiece to be plated is used as a cathode. The cation of the plated metal is reduced on the surface of the workpiece to be plated to form a plating layer. In order to eliminate the interference of other cations and make the coating uniform and firm, it is necessary to use a solution containing a plating metal cation as a plating solution in order to maintain the concentration of the plating metal cation unchanged. The purpose of electroplating is to plate a metal coating on the substrate to change the nature or size of the substrate surface. Electroplating enhances the corrosion resistance of metals (more corrosion-resistant metals are used for plating metals), increases hardness, prevents abrasion, improves electrical conductivity, smoothness, heat resistance, and aesthetic appearance.

Classification

Electrogalvanizing: It is the process of using electrolysis to form a uniform, dense, well-integrated metal or alloy deposit on the surface of the part.

Compared with other metals, zinc is a relatively inexpensive and easily-plated metal and is a low-value corrosion-resistant plating. It is widely used to protect steel parts, especially to prevent atmospheric corrosion, and for decoration. Plating techniques include slot plating (or rack plating), barrel plating (suitable for small parts), automatic plating and continuous plating (suitable for wire, strip).

Domestic classification by electroplating solution can be divided into four categories:

Cyanide galvanizing

Since (CN) is highly toxic, environmental protection places stringent restrictions on the use of cyanide in electrogalvanizing and continues to promote the development of reduced cyanide and substituted cyanide galvanizing bath systems, requiring the use of a low cyanide (microcyanide) bath. . After electroplating with this process, the product quality is good, especially color plating, and the color remains good after passivation.

Zinc Plating

This process evolved from cyanide galvanizing. At present, there are two major factions in the country, namely: a) "DPE" series of Wuhan Material Protection Institute; b) "DE" series of Radio and Television Institute. Both are zincate zincate alkaline additives; PH value of 12.5 ~ 13. With this process, the lattice structure of the coating is columnar, and it has good corrosion resistance and is suitable for color galvanization.

Chloride zinc plating

This process is widely used in the electroplating industry, accounting for up to 40%. After passivation (Lanbai) can be zinc chromium (equivalent to chrome plating), especially after the addition of water-soluble varnish, it is difficult for laymen to identify whether it is galvanized or chrome-plated. This process is suitable for white passivation (blue white, silver white).

Sulfate galvanizing

This process is suitable for continuous plating (wire, strip, simple, coarse large zero, components). low cost.