- 2021-05-27 17:31:36
Nickel electroplating is in an electrolyte composed of nickel salt (called main salt), conductive salt, pH buffer, and wetting agent. The anode uses metallic nickel, and the cathode is a plated part. Direct current is applied to the cathode (plated part). A uniform and dense nickel plating layer is deposited. Bright nickel is obtained from the bath with brightener, and dark nickel is obtained from the electrolyte without brightener.
(1) Features, performance and uses of electroplated nickel:
1. The stability of the electroplated nickel layer in the air is very high. Due to the strong passivation ability of metallic nickel, a very thin passivation film can be quickly formed on the surface, which can resist the corrosion of the atmosphere, alkali and certain acids. .
2. Electroplated nickel crystals are extremely small and have excellent polishing performance. The polished nickel coating can get a mirror-like gloss appearance, while maintaining its gloss for a long time in the atmosphere. Therefore, the electroplated layer is often used for decoration.
3. The hardness of the nickel plating layer is relatively high, which can improve the wear resistance of the product surface. In the printing industry, the nickel plating layer is commonly used to increase the hardness of the lead surface. Due to the high chemical stability of metallic nickel, thicker nickel coatings are also commonly used in some chemical equipment to prevent corrosion by the medium. Nickel-plated layer
It is also widely used in functional aspects, such as repairing worn and corroded parts, and using brush plating technology for partial electroplating. The electroforming process is used to manufacture electroformed plates, record molds and other molds in the printing industry. The thick nickel-plated layer has good wear resistance and can be used as a
Grind the coating. Especially in recent years, composite electroplating has been developed, which can deposit a composite nickel plating layer with wear-resistant particles, and its hardness and wear resistance are higher than that of the nickel plating layer. If graphite or fluorinated graphite is used as the dispersed particles, the nickel-graphite or nickel-fluorinated graphite composite coating will have a good
Self-lubricating, can be used as a lubricating coating. Black nickel coatings are also widely used as coatings or decorative coatings for optical instruments.
4. Nickel plating has a wide range of applications and can be used as a protective decorative coating. On the surface of steel, zinc die-casting, aluminum alloy and copper alloy, it can protect the base material from corrosion or play a bright decoration; it is also often used as other coatings. The middle plating layer is plated with a thin layer of chromium or an imitation gold layer on it,
Its corrosion resistance is better and its appearance is more beautiful. In terms of functional applications, the thickness of nickel plating on the parts of special industries is about 1~3mm, which can achieve the purpose of repair. Especially in the continuous casting of molds, surface molds of electronic components, alloy die-casting molds, complex-shaped aerospace engine parts and the manufacture of micro-electronic components, etc., are more and more widely used.
5. In electroplating, due to the many excellent properties of electroplated nickel, its processing volume is second only to electroplated zinc, and its consumption accounts for about 10% of the total nickel output.