Elektroplating

Electroplating, sometimes written elektroplating in certain languages, is an electrochemical process that deposits a thin layer of metal onto a conductive substrate. The object to be plated acts as the cathode in an electrolytic cell, while a metal anode or a soluble metal source provides metal ions to the electrolyte. When an electric current passes, metal ions are reduced at the surface and form a continuous coating, while ions from the anode replenish the bath.

A typical plating bath contains a salt of the desired metal, complexing agents to improve deposition characteristics, and additives that influence brightness, hardness, and throwing power. Common coatings include nickel, chromium, copper, gold, silver, zinc, tin, and various alloys. Nickel is widely used for wear and corrosion resistance; chromium for hardness and decorative appeal; zinc for sacrificial protection; gold and silver for electronics and jewelry.

Surface preparation is essential and usually involves degreasing, descaling, and activation. In many cases a strike layer or pre-coating is applied to improve adhesion. Process parameters such as current density, bath temperature, pH, and agitation are controlled to achieve uniform coating thickness. Plating thickness typically ranges from a few micrometers to tens of micrometers, depending on application.

Applications span automotive, electronics, aerospace, jewelry, and corrosion protection. Environmental and safety concerns are significant, as some baths use cyanide or hexavalent chromium and generate hazardous wastes. Safer alternatives include trivalent chromium baths and non-cyanide nickel or copper systems, with waste treatment and regulatory compliance integral to operation.