Etching is the partly removal of the surface layer of a metal product with the help of a chemical reaction. This technology has been known to man for several millennia along with coining and blackening. It was used to finish metal parts of weapons and household utensils, jewelry and ritual objects. Nowadays, metal etching is mostly used for creating images and inscriptions on metal products.
Before etching, those areas of the metal surface that should not be etched are covered with protective coating, which is resistant to the etching agent. Next, the part is exposed to an acidic environment or immersed in a reservoir with an electrolytic liquid. The longer the part is processed, the larger the metal layer is corroded by an aggressive environment. There are several main methods of metalworking: chemical, electrochemical and ion-plasma.
Chemical etching of metal products implies the use of various acids. The materials can be effectively etched in a solution of sulfuric acid. Electrochemical method involves an electrolyte solution. During the etching process, a current is passed through it. Thus, the work is faster than during chemical treatment. Ion-plasma method excludes the use of acids and other chemical compositions. The metal is processed using ionized plasma, which is fed to it in separate beams.
