Material Plating and Finishes

Abstract

Metal plating is the process of deposition of one metal upon another. It can be accomplished by electroplating, catalytic chemical reduction, vacuum deposition, or hot dipping. Electroplating, by far the most common process, is applied by making the base metal cathodic in an aqueous solution of the salt of the plating metal, and then passing direct current through the solution to deposit the coating metal by electrolysis. These processes change the reaction of the base material, or substrate, to its environment or impart special properties to the material. The properties of the plating vary with the composition of the solution, current density, agitation, and solution temperature. Hardness, conductivity, solderability, and corrosion-resistance are generally the most important plating properties, since coating-life is usually dependent upon these factors.