- This article is about the industrial process. For the philatelic concept, see postage stamp plating .
Plating is the general name of surface-covering techniques in which a metal is coated onto a solid surface. Plating is indispensable for the manufacture of computers, mobile phones, and electronic devices as well as for surface treatment techniques. Moreover, it is a key technology for the development of new machines. It is also used for decorative purposes, typically to provide a silver or gold exterior. Recently, plating techniques have been done on a smaller scale than the microscopic, so it is appropriate to call them "nanotechnology."
There are several plating methods. For example, in one method, a solid surface is covered with a metal sheet and then plated by heating. Other plating techniques include vapor deposition under vacuum, sputtering, and methods using vacuum conditions or gas. Recently, however, only plating techniques using a liquid tend to be called "plating".
Electroplating is one of the plating techniques. One electroplating method grows a plating film by melting a positive electrode under an outer electric current source and a soluble positive electrode. Another method uses an insoluble metal, for example, platinum, titanium, stainless steel, or carbon, as the positive electrode, adding a metal for plating as a reagent and then depositing the metal from the reagent. The former method is useful for electrotyping , forming a thick plating film, and making copper sheets by continuous plating. The latter method is useful for plating insoluble metals and noble metals and making functional films by using alloys.
Metallizing refers to the process of coating metal on non-metallic objects.