Nickelplating

Nickel plating is the process of depositing a thin layer of nickel on a metal surface by electrolysis to improve corrosion resistance, wear resistance, hardness, and appearance. It is widely used in automotive, aerospace, electronics, hardware, and tooling.

In electroplating, the workpiece is thoroughly cleaned and activated, then immersed in an aqueous nickel plating bath. An electric current drives nickel ions from the bath to the cathode (the workpiece) while nickel from the anode replenishes the ions. The most common bath is the Watts bath, based on nickel sulfate with nickel chloride and boric acid; additives control brightness and deposit properties.

Variants include bright nickel plating, which uses organic additives to produce a reflective finish, and alloy deposits such as nickel–phosphorus or nickel–boron that offer higher hardness and corrosion resistance. Electroless nickel plating is a related autocatalytic process that yields uniform coatings on complex shapes and is widely used for wear and corrosion protection.

Coating thickness ranges from decorative applications requiring only a few micrometers to functional parts demanding tens of micrometers. Nickel coatings provide good corrosion resistance, moderate lubricity, and ease of soldering, but nickel can cause allergic reactions in some people. Waste from plating processes is regulated and must be treated.

Common quality issues include dull or matte finishes, pitting, burning, blistering, and poor adhesion caused by insufficient cleaning, improper pH, or incorrect current density. Post-treatment steps may include rinsing, passivation, or applying a topcoat such as chromium or a polymer layer for enhanced wear resistance.