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Electroplating is the technology of depositing metals from solutions onto metallic surfaces by electrolysis. The resulting coating is tightly bonded to the surface and is mineral in nature. Coatings may be used to protect against oxide formation (rust) on base metal surfaces, to assist in electrical conductivity, and in decoration. Popular coatings include cadmium, nickel, zinc and silver.

Cadmium is a good conductor of electricity, has low contact resistance and is the only plating which will not arc weld. Primarily used to protect iron and steel from corrosion, it provides superior corrosion resistance to zinc in many environments (especially in marine and tropical areas) and is more resistant to organic vapors from electrical insulation and to formic acid from paint films. Cadmium does not form bulky corrosion products and solders readily with non-acid fluxes.

Possessing good lubricity, cadmium prevents galling between sliding metal surfaces. Its good ductility enables parts to be formed after plating – reasons why more cadmium is used for electroplating than for any other purpose.

Zinc plating has been the most popular choice for corrosion protection, due to its low cost. The move to provide higher quality and longer lasting finishes has resulted in a shift to more use of alloy zinc deposits – especially in the automotive, aerospace and electrical industries.