Source of metal atoms and fast gas molecules for coating deposition on complex shaped dielectric products

Abstract

Beam-assisted deposition of wear-resistant coatings on complex shaped dielectric products is used as a source of slow metal atoms and fast gas molecules with coinciding trajectories of their movement from a common emissive grid to the products. This allows keeping the ratio of metal atom flow density to that of fast molecules constant as well as uniformity of deposited coating properties at the whole surface of the planetary rotating inside vacuum chamber products, including their cavities. The fast molecules are produced due to charge-exchange collisions of ions accelerated by potential difference between a plasma emitter inside the source and secondary plasma inside the chamber. The plasma emitter is produced by glow discharge with confinement of electrons in an electrostatic trap formed by a cold hollow cathode and an emissive grid the latter being negative to both the cathode and the chamber. Metal vapor is produced due to sputtering of a target placed at the bottom of the hollow cathode by ions from the plasma emitter accelerated by a negative bias voltage 2kV.