PVD-technology
In physical vapor deposition of metal coatings a cathode solid material turns to a gas with further material deposition onto a substrate (specimen, component, and tool). The cathode material may turn to gas phase as a result of evaporation (due to heat) or cathode sputtering (due to ion bombardment).
Evaporation occurs due to resistive heating, induction heating, electron bombardment, low-voltage arc, cathode or anode arc, and laser beam. The processes may be independent or additionally followed by ionization in reactive gas and under bias voltage.
Cathode sputtering occurs due to high-energy ions which acquire desired energy, are accelerated in electrical field and sputter cathode material atoms. Sputtering may take place at direct current or high-frequency current in a reactive gas or otherwise, under bias voltage or otherwise, and extra magnetic field.
In mechanical engineering most extensive use is enjoyed by magnetron and vacuum-arc PVD coating methods.