Nickel electroplating is one of the oldest coating and plating techniques available, and it has a wide range of applications. It has grown popular owing to its low cost and enticing features because it is an inexpensive alternative. Nickel electroplating is used in a variety of industries, including aviation and telecommunications. As a result, Electro nickel plating, commonly known as nickel electroplating or nickel electro-deposition, is becoming a more prevalent production method. Electro nickel plating is a technique that coats a conductive substance, usually metal, with a thin coating of nickel using an electrical current. Stainless steel and other metals are also utilised in electroplating.
The working of nickel electroplating
A negative charge must be supplied to the base material to appropriately transfer nickel onto the surface of a product. A conductive wire is generally used to connect the product to a rectifier, battery, or other power sources. A nickel rod is then linked to the positive side of the rectifier or power source similarly. Following the initial processes, the base material is immersed in a solution containing salt with a chemical composition and the electroplating metal. This solution for electro nickel plating is made up of water and nickel chloride salt.
The nickel chloride salt dissociates into negative chloride ions and positive nickel cat-ion due to the electric current present in the solution. The base metal’s negative charge attracts positive nickel ions, whereas the nickel rod’s positive charge attracts negative chloride anions. The nickel in the rod oxidises and dissolves in the solution as a result of this chemical reaction. The oxidised nickel is drawn to the base material and covers the product from there.
The history of nickel electroplating
In 1805, an Italian scientist called Luigi Brugnatelli created electroplating. He was known as one of “Science’s Fathers,” and he used the Voltaic Pile, discovered by his colleague Alessandro Volta in 1800, to accomplish gold electrodeposition. The Belgian Journal of Physics and Chemistry published his work on electroplating. However, Napoleon Bonaparte, the dictator, rejected Luigi Brugnatelli’s work, forcing him to conceal future publishing.
Potassium cyanide was discovered as a suitable electrolyte for gold and silver electroplating over 40 years later by John Wright of Birmingham, England. John Wright was the first to demonstrate that electroplated things could be immersed in a tank of silver in a solution with an electric current running through it. In 1840, Henry and George Richard Elkington patented John Wright’s electroplating method. Despite competition from many other innovators, the Elkington brothers were the first to get the patent.
Nickel electroplating is the technique of electrolytically depositing a nickel coating onto a metal surface. Parts that are to be plated must be clean and free of dirt, corrosion, and flaws before plating. Before the plating procedure, a product must be cleaned and protected.
Getting Your Product Ready for Electroplating
- Masking is the act of covering a specific portion of a surface to prevent it from being exposed during the anodising or electroplating process.
- Heat treating a metal softens it and improves its formability. To enhance strength, it makes components more challenging.
- Pickling is a process for removing impurities such as stains, inorganic pollutants, and ferrous metal rust that might damage the product’s usability. To eliminate the contaminants, an acid solution is known as “pickled liquor” is usually employed.
- Etching is the technique of cutting into the unprotected areas of a metal surface with a strong acid or mordant (dye fixative) to produce a design.
Following preparation, the component is submerged in an electrolyte solution and utilised as the cathode (an electrode from which a conventional current leaves a polarized electrical device). Nickel ions are formed when the nickel anode is dissolved in the electrolyte. These ions go through the solution to the cathode and deposit there. Nickel electroplating necessitates a nickel striking process for adhesion, followed by a chromium finish to increase the nickel deposit’s corrosion resistance and anti-tarnish properties.
A strike layer attaches to the base material’s thin layer of high-quality nickel plating. Bright and semi-bright nickel can be electroplated in nickel electroplating baths. Bright nickel is typically utilised for aesthetic or decorative purposes as well as corrosion resistance. Semi-bright deposits are commonly used in engineering applications that need increased corrosion resistance, flexibility, and electrical conductivity.
Types of Nickel electroplating
- Bright Nickel Plating—Because of its strong levelling qualities, bright nickel plating covers polishing lines and other surface defects, making it a desirable alternative. Because of its high sulphur content, it has a brilliant mirror-like sheen and strong conductivity. It is, however, less resistant to corrosion than other kinds of nickel plating.
- Electroless Nickel Plating– Unlike other nickel plating methods, electroless nickel plating employs an auto-catalytic reaction rather than an electric current application procedure. Many people like it because of its uniform covering and ability to deposit on non-conductive surfaces. It’s great for avoiding corrosion and wear on anything that needs more toughness.
- Dull Nickel Plating is a procedure that is quite similar to brilliant nickel plating in terms of producing a long-lasting dull, matte appearance. The corrosion resistance and malleability of dull nickel plating are unrivalled. Because its coating may grow thickness and is helpful for abrasion and dimensional correction reasons for movement, it is suitable for machine components and springs.
Applications of Nickel Electroplating
- Nickel-plated steel is used to make bright and durable silver currency, which signals value to residents. Furthermore, governments like plated coinage for its low cost and extended life. Mints like the way nickel surfaces take an impression from dies, resulting in crisp clarity and detail that will last for decades. Vending machine manufacturers and operators use the magnetic signature of the nickel to authenticate the coinage and enable only legal transactions. When the coins approach the end of their useful lives, the nickel and steel are recycled, and a new cycle of usage begins.
- Deposition on ABS (Acrylonitrile butadiene styrene) plastic mouldings provides durability for automotive, consumer items, builders’ hardware, taps, electronic equipment, and various other applications requiring bright or satin coatings.
- In terms of safety and dependability, the aircraft sector has the most stringent technological standards. All materials, coatings, and maintenance processes for aeroplane components are subject to rigorous standards, and all are thoroughly evaluated and tested before use. Nickel-based plating is significant in aerospace applications because of its unique functional qualities, including good adhesion, corrosion resistance, hardness, wear and erosion resistance, and consistent layer thickness, even on complicated components.
- Plating and coating are particularly essential in the automotive sector, where coating innovation is fast progressing, and nickel is required for safety and lifespan. Nickel plating on plastics and aluminium offers significant aesthetic and durability benefits. Electrolytic zinc-nickel and electroless nickel plating are two more considerable plating methods. Zinc-nickel plating is exceptionally efficient in protecting bolts, fasteners, and components from corrosion, such as salt spray, and is thus in great demand for automotive bolts, pins, and features.
- Brush plating is a specialised technique for electroplating machine components on-site. Instead of disassembling and transferring the details to an industrial plating facility, brush plating may be done with mobile devices that can be transported to the aircraft’s location. This may save a lot of money when it comes to aeroplane maintenance. The method is widely used in the aerospace sector, especially for landing gear repair.
Benefits of Nickel Electroplating
Electroplating, in general, enhances a wide variety of properties that aren’t inherent in the underlying material. These are some of the advantages:
- Increased corrosion resistance
- Hardness has improved.
- Superior durability
- Abrasion resistance
- Ductility has improved.
Because of its excellent flexibility, corrosion resistance, and hardness, nickel is a good choice for electroplating metal. Electro nickel plating may also increase the brightness and look of a product. Different nickel-plating chemicals used in the process provide various aesthetic effects, including semi-bright, completely brilliant, matte, pearl, and satin finishes.