PVD: evaporative deposition
Coating drive components with an amorphous carbon film by the plasma-assisted PVD method.
||With physical vapor deposition the film material is present inside the vacuum chamber in liquid or solid form. The material vaporizes on an atomic basis as molecule or cluster, reaches the surface of the substrate by kinetic (physical) movement and deposits itself there (condenses).
A distinction is drawn between evaporative deposition and sputtering. In evaporative deposition the coating material is melted. The resulting vapor then deposits itself on the substrate surface. With sputtering the coating material is in solid form. It is atomized by being impacted by accelerated gas particles. The particles thus ejected reach the substrate surface where they form the coating.
Even chemical components can play a role in PVD processes for the deposition of carbon coatings: these take place in the gas phase or on the substrate surface.
PVD processes are in most cases carried out with plasma assistance (plasma-assisted CVD, PACVD). The application of electrical fields causes the process gases to become ionized. The charged particles are further accelerated by the electrical fields or by additionally applied magnetic fields. This increases the deposition rate and improves coating properties.