Electroless nickel plating is to deposit a uniform and compact nickel coating on the cathode (plated part) in an electrolyte composed of nickel salt (main salt), conductive salt, pH buffer and wetting agent, with metal nickel as anode and direct current as cathode. Bright nickel is obtained from plating solution containing brightener, while dark nickel is obtained from electrolyte without brightener.
Electroless plating, also known as electroless plating and autocatalytic plating, refers to the process of reducing and depositing metal ions in aqueous solution on the surface of solid substrate under certain conditions.
Characteristics, properties and uses of nickel plating;
1. The electroplated nickel layer has high stability in air. Because of its strong passivation ability, metallic nickel can quickly form an extremely thin passivation layer on the surface energy.
Membrane, can resist the corrosion of atmosphere, alkali and some acids.
2. Electroless nickel plating has extremely fine crystals and excellent polishing performance. After polishing, the nickel coating can obtain the appearance of mirror luster, and at the same time, it is in large
Its luster can be kept in the air for a long time. Therefore, electroplated layers are often used for decoration.
3. The hardness of the nickel coating is relatively high, which can improve the wear resistance of the product surface. Nickel plating is often used in printing industry to improve the hardness of lead surface.
Due to the high chemical stability of metallic nickel, some chemical equipment often adopts thick ballast coating to prevent the corrosion of medium. Nickel coating
It is also widely used in function, such as repairing worn and corroded parts and using brush plating technology for local electroplating. Adopt electroforming
The process used in the printing industry to manufacture electroformed plates, record molds and other molds. Thick nickel plating layer has good wear resistance and can be used as resistance.
Abrasive coating. Especially, the composite electroplating developed in recent years can deposit a composite nickel coating with wear-resistant particles, and its hardness and wear resistance are better than electroplating.
The nickel layer is higher. If graphite or graphite fluoride is used as dispersed particles, the obtained nickel-graphite or nickel-graphite fluoride composite coating has good properties.
Self-lubricating, can be used as lubricating coating. Black nickel coating is also widely used as coating or decorative coating for optical instruments.
4. Nickel plating has a wide range of applications, and can be used as a protective decorative coating to protect the substrates on the surfaces of steel, zinc die castings, aluminum alloys and copper alloys.
The material is not corroded or plays the role of bright decoration; It is also often used as an intermediate coating for other coatings, which is plated with a thin layer of chromium or imitation gold.
Its corrosion resistance is better and its appearance is more beautiful. In functional application, the thickness of nickel plating on parts in special industries is about 1~3mm, which can achieve the purpose of repair.
Yes Especially continuous casting crystallizer, electronic component surface mold, alloy die-casting mold and aero-engine with complex shape.
Components and microelectronic components are widely used in manufacturing industry.
5. In electroplating, because electroplating nickel has many excellent properties, its processing ability is second only to electroplating zinc, and its consumption accounts for the total nickel output.
10%.
Characteristics, properties and uses of electroless nickel plating;
1, uniform thickness and good platability are one of the characteristics of electroless nickel plating, which is also one of the reasons for its wide application.
The uneven thickness of electroplating layer caused by uneven current distribution is avoided. When electroless plating, as long as the surface of the part is in contact with the plating solution, it will disappear in the plating solution.
Consumable parts can be replenished in time, and the coating thickness of plated parts is basically the same, even for grooves, gaps and blind holes.
2. Electroplated parts have no hydrogen permeation and hydrogen embrittlement, and there is no need to remove hydrogen after electroless nickel plating.
3. Many materials and parts have better corrosion resistance and high temperature oxidation resistance than nickel plating.
4. It can be deposited on the surface of various materials, such as steel-nickel base alloy, zinc base alloy, aluminum alloy, glass, ceramics, plastics, semiconductors and other materials.
Thus creating conditions for improving the properties of these materials.
5. Generally, DC motor or control equipment is not needed for electroplating.
6, the heat treatment temperature is low, as long as the temperature is below 400℃ for different time, different corrosion resistance and wear resistance can be obtained, so it is especially suitable.
Functional coatings on parts with complex shapes and wear-resistant and corrosion-resistant surfaces.