These are mainly coatings of low thicknesses sprayed in gaseous form (a few microns) usually hard and rather chemically stable.
They are deposited on other metals but also on polymers, ceramics, glass, and composite materials.
Two families of techniques, very common, are used for the realization of these deposits:
Cathodic spraying or evaporation by electron gun, are used in the electronic and optical industries and allow to make deposits of insulating layers but also of metal layers (aluminum, tungsten, titanium, chromium, etc …) which will intervene for the realization of interconnection layers in integrated devices but also in surface treatment to improve friction properties, wear, resistance to oxidation of components
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