Metal finishing is a term that is used widely to cover a number of different processes. The end result of these processes is the same, which is to cover the surface of some metal object with another metal coating. This process changes the surface of the original object. The object that is being coated is called a substrate. The intention of this type of process is to make the object more durable or to make it look better. This process may include polishing, cleaning, or improving the object in some way.
Electroplating is one of the types of metal finishing. This is when metal ions are deposited on the object with an electric current. Often, the terms electroplating, or plating, and metal finishing are used interchangeably. They are not always the same, as electroplating is a specific type of metal finishing. Some additional benefits of metal plating include reducing corrosion and the problems it causes. It can act as a primer to help paint adhere to the object. It can help make the object stronger and increase its durability. Metal plating helps to reduce friction while making the object look better. Once an object is metal-plated, it is easier to solder. It can improve the resistance to chemicals for the object.
Electroplating happens when metal or some type of alloy is deposited on the surface of an object. Electric currents pass through a liquid bath containing the object and metal ions that are dissolved. The object attracts the metal ions while in the bath. There is a process prior to the bath that cleans, rinses, and strips the object to create a clean surface to begin plating. There are ways to handle bulk electroplating where the objects are attached to a rack or tumbled through a barrel. This process can be used to coat plastic material, as well as other materials that are not metal. This process is much more difficult and is typically only done by someone that is an expert in electroplating.
Electroless plating is a similar process, but it does not use electricity. The object is immersed in a bath that contains nickel or copper, but sometimes it contains other metals. This process uses a chemical reaction instead of electricity. The bath contains other chemicals and agents to ensure the plating, as well as the stability of the solution to replace the use of electricity.
Electrocoating uses the same processes as electroplating. The object is put into a solution bath the contains the metal to coat the object and an electric current is added. The difference here is the metal ions. There are no metal ions in electrocuting. Instead, the solution uses paint or epoxy particles that have been electrically charged. After this, the particles are attached to the object for coating.
Electropolishing is a metal finishes process that is nothing at all like electroplating. This process removes, not adds, metal ions to the surface of the object. This gives the object a smooth surface. The object is placed in an electrolyte bath and then connected to a power source. This process removes debris and burrs from the object to polish it and remove divots in the object. In some cases, it can help to make the object smaller.