This is the common and best method of applying coating of resistant method over the surface of base metal by passing electric current through electrolytic solution soluble salt of coating metal object of electroplating. For decoration and better appearance. To increase commercial and decorative value base metals like Fe, Cu, Al are electroplated with more resistance metal like Ni, Cr, Pt, Au. For corrosion protection electroplating is widely used for depositing protective coating ions and metal articles are protected from corrosion by plating them with Zn, Ni, Cu, Cr Steel articles are usually given three successive coating of Cu, Ni , Cr , Cu & Ni protection against rusting. While Cr gives shining & clean surface appearance. This type of three coat plating is used in automobiles industry. Process: 1] The article to be electroplated is first cleaned with organic solvent tetrachloride ethylene to remove oil & greese.2] Then it is made free from scales & oxides by treating with H2SO4 or HCl. Ni-Cu plating dil HCl is used . Cr plating dil H2SO4 is used. The cleaned article is then dried & polished & made cathode. Anode is coating material itself or an inert material of good electrical conductivity like graphite. The electrolytic solution is soluble salt of coating metal. The electrolytic solution is kept in electroplating tank. The anode & cathode are dipped in electrolyte. When direct current is passed the coating metal passes into solution as metallic ions. If anode is inert material ions, ions produced by electrolyte. The metallic ions migrate to cathode & get deposited on article. To get smooth & brighter deposit the favorable conditions are Low temperature 2. Medium current density 3. High metal ion concentration. If anode is made up of graphite then electrolytic salt is added continuously in order to maintain metal ion concentration. The process of electroplating is nonstop. Since anode is not consumed. Reaction at anode: Cu++ +2e-→ Cu Reaction s in electrolytic solution: H2O→ H+ +OH-- CuSO4 →Cu++ +SO4— Reaction at anode: Cu→ Cu++ + 2e--
Copper gets deposited on the article which is made as cathode & Cu++ formed by anode combines with SO4—ion & migrate to Cu anode to form CuSO4 & CuSO4 dissolves in electrolyte.

Applications of electroplating: Electroplating method is applicable for metals & alloys, as some alloys also undergo corrosion. In internal combustion engine surface wear & tear can be avoided & running performance can be improved by applying Cr plating Electroforming: If thick layer is deposited then it is called as electroforming. Many parts used in aircraft industry they requires electroforming. Electroplating is done on metals as well as nonmetals like wood, glass, leather & porcelain for increasing strength & making surface conducting.