Electroplating

Electroplating means carving a metallic coating on an object by a chemical process. Many fashion jewelry are treated in this manner to give dissimilar effects and finishes to the jewelry. The process used in electroplating is called electrodeposition.

Electroplating is the process of using electrical current to reduce metal cations in a solution and coat a semiconductive object with a thin layer of metal. The primary application of electroplating deposits a layer of a metal having some desired property onto a surface lacking that property. Another application uses electroplating to build up thickness on undersized parts.

Usually brass is electroplated with EPNS ie, electroplated nickel silver, but there can be other plating combinations as well. ABS Plastic can also be electroplated. The final product is obtained in different coatings and textures.

Functionality
Electroplating is done by creating a negative charge in the object and immersing into an electrolyte solution. The electrolyte solution contains the salt of the metal that has to be coated. The metal ions of the salt have a positive charge and get attracted to the negatively charged object. These ions then get deposited on the object. On the other end of the electrode is the pure metal , also immersed in the electrolyte. The solution maintains its stability using the pure metal.
While most plating cells use an uninterrupted direct current, some employ a cycle of 8–15 seconds on followed by 1–3 seconds off. This permits high current densities to be used while still producing a quality deposit. In order to deal with the mismatched plating rates that result from high current densities, the current is even sometimes reversed, causing some of the plating from the thicker sections to re-enter the solution. In effect, this allows the "valleys" to be filled without over-plating the "peaks." This is common on rough parts or when a bright finish is required.

Thick coat for long life span
The life of an electroplated object depends on the thickness of its coating. Thick plating gives a long enduring finish but more cost. The right equilibrium has to be preserved to obtain a good life span and desired finish.

The current density in this process strongly influences the deposition rate, plating adherence, and plating quality. This density can vary over the surface of a part, as outside surfaces will tend to have a higher current density than inside surfaces. The higher the current density, the faster the deposition rate will be, although there is a practical limit enforced by poor adherence and plating quality when the deposition rate is too high.