It is to coat metals on surfaces of materials by using current.
Generally speaking, it is a process whereby surfaces of parts(materials) are coated by metals using direct current. There are a wide range of applicable parts for electroplating and it is used to get advantages such as corrosion protection, abrasion and wear resistance(stretch resistance), various aesthetic purposes, curbing of corrosion under high temperature, boost of adhesion and to get electrical property.
We know that steel is easy to rust if not properly protected. Rust can be avoided by zinc coating through electroplating. Some metals such as chrome are harder than other metals and can be used in plating for durability and abrasion resistance. In addition, chrome electroplating is widely used in the aviation and space industry to take advantage of its strong heat resistance and protect jet engine components from high temperature during their operation. Automobile bumpers, piping facility, dishware for dining are typical examples of coated parts. Thin coil-shaped steel can be coated by tin. There are three basic reasons for it. Tin has good corrosion resistance from attacks of acid foods, good connection with interface along with no toxicity.
Gold plating to interface in electric circuits allows low contact resistance and conductivity. These sorts of metals are widely used in the electrical industry.
Electroplating is also used to protect abrasive parts such as shafts and crankshafts. For example, plated chrome functions as durable coating with good surface hardness. Moreover, it maintains corrosion resistance and abrasion resistance(though a bit reduced) to protect parts from oxidation. Printing circuit boards also form electric circuits by electroplating. This type of components is widely used in the electric & electronic, computer industries. Perhaps, most commonly-used metals are zinc, nickel and tin. Normally these metals prevent rust on coated parts of steel. On the other hand, silver and gold are widely used in the jewelry industry. Gold and other jewels are also used in the electronics industry.
It has been developed relatively recently. Instead of using current to plate metals, chemicals are added to plating baths. Those chemicals work like a battery or rectifier. One of main merits of electroless plating is equal plating width. Its another merit is the ability to plate non conducting materials such as plastics. Development of electroless plating greatly contributed to the development of the electronics and computer industries. However, it is not that all the metals are plated by electroless plating. Nickel, copper, cobalt, gold, platinum can be plated by this method.