electrolyte selection
Many different metals can be used in electroplating, however, determining the right electrolyte is important for electroplating quality. Some electrolytes are acidic, basic, metal salts or molten salts. When choosing the type of electrolyte, you should consider things such as corrosion, resistance, brightness or reflectivity, hardness, mechanical resistance, flexibility and wear resistance.
level preparation for plating
The purpose of surface preparation prior to plating with another metal is to ensure that the surface is clean and free of contaminants that may interfere with bonding. Contamination often prevents deposition and adhesion. Typically, this is done in three steps: cleaning, polishing, and rinsing. Cleaning usually involves the use of special solvents such as alkaline cleaners, water or acid cleaners to remove layers of oil from the surface. Finishing also includes surface modification, which causes the parts to be hardened and the use of metal layers.
Washing leads to the final product and this finalization is related to plating. Physical and chemical cleaning are two specific methods for surface preparation. Chemical cleaning involves the use of solvents that have surface-active chemicals or chemicals that can react with the metal/surface. In physical cleaning, mechanical energy is used to remove contaminants. Physical cleaning includes abrasion with a brush and ultrasonic stimulation.
electrical plating
In recent years, the industry Electroplating of metals has seen a significant growth in response to market needs. The growth of electronics and air and space industries and the need for reliable, quality materials with controlled properties have played a significant role in this growth and progress.
reasons for plating
chrome
The most familiar electroplating coating is chrome, which is used to cover bicycles, household appliances, hospital equipment, fittings, wires and many other things. The color of this coating is generally light, but other colors such as black are also available.
Contrary to the name, chrome plating is generally a nickel coating (which means that first a nickel coating is placed on the surface and then the chrome layer sits on this nickel layer, the thickness of the nickel layer is greater than the chrome layer) which in some cases It is also done on copper, where only a thin layer of chrome is placed on the top layer of the coating. The brightness, glossiness or dullness of the surface depends on the structure of nickel, but for the black surface, other additional steps must be done. Chromium, although a base metal, quickly forms a strong, impermeable oxide film that makes it neutral under normal conditions. Therefore, the chrome coating is very resistant to tarnishing and corrosion and will be an ideal choice for decorative purposes.
Copper and its alloys
Thin electrical deposits of copper, bronze and especially brass are among the popular items in decorative plating of surfaces. In this type of metal plating, first a layer of nickel is placed on the surface, then copper or its alloys are placed on the nickel, and at the end, a layer of clear varnish covers the surface of the product.
Precious Metals
Silver and gold are among the oldest precious metals that have been used for decoration. Jewelry, watches, dishes, etc., are items on which silver and gold plating can be seen.
Corrosion Protecting
To protect different surfaces from corrosion, plating with metals such as zinc, cadmium, tin and its alloys and silver is done on the desired surface.
Engineering Applications
Engineers and designers use metal plating and its properties in many cases, which include:
Creating hard surfaces (nickel, chrome, etc.)
bearing coating
Types of Electrolyte Metal Plating Techniques
A large number of equipments can be used for electrolytic plating. The choice of equipment depends on the size of the parts, geometry, required power, electrolyte and metal that is to be deposited. Copper plating Copper metal is a good and soft electrically conductive metal and is widely used in the industry due to the absorption of thermal stresses and is usually used as the bottom layer. The unique color of copper makes it suitable for decorative applications. Copper plating on iron and aluminum is very common. Steel plating The constituent elements of steel or stainless steel are iron, chrome and nickel alloys. This alloy is more resistant to corrosion, this feature is due to the presence of chromium. This metal has self-healing properties and in case of scratching this layer is formed again. Steel is a popular metal in the production of jewelry due to its anti-rust property, color and luster. This metal can be used both as base metal and cover metal. Roy Steel parts plated with zinc include connecting wires, switching boxes and connecting and disconnecting electric current and metal sheets. Zinc coating provides high resistance against corrosion. nickel Generally, nickel plating is used for corrosion prevention and decorative purposes. In these cases, usually brass, steel and zinc act as the substrate. Some car parts have nickel coating. Gold plating In this method, a thin layer of gold is deposited on other metals. The bottom layer is generally made of silver or copper. The gold layer is resistant to corrosion and has a very high electrical conductivity, which is used in electrical connectors and printed electrical circuits. The main problem of gold plating on copper is that copper atoms tend to penetrate the gold layer, which causes spots on the gold surface and forms a layer of sulfur oxide on the surface. To prevent this, first a layer like nickel is placed on the copper as a barrier, and then gold is placed on it (nickel does not tend to penetrate gold). In some cases, gold plating is used to improve the appearance and ornamental use.
