Electroplating
Electroplating is the process of applying a thin layer of other metals or alloys on the surface of certain metals by electrolysis. It is a process of applying a metal film to the surface of metals or other materials to prevent oxidation (such as rust), improve wear resistance, electrical conductivity, reflectivity, corrosion resistance (copper sulfate, etc.) and enhance aesthetics. The outer layer of many coins is also plated. Translated with www.DeepL.com/Translator (free version)