Principles and applications of vacuum arc coatings

The development of vacuum arc coatings, commencing a century ago with Thomas Edison and continuing through the recent development of industrial-scale batch coating machines, is reviewed. Most of the work exploited the high ionization, plasma production rate, and ion energy intrinsic in the cathode spot arc to deposit metals, diamondlike carbon Si, and, with the presence of a background gas, various ceramics. Deposition rates of up to 400 μm/s were achieved in pulsed operation. Various techniques were developed to control the motion and location of the cathode spots and to reduce the macroparticle contamination of the coatings. Hot electrode vacuum arc modes were investigated recently as well. Simple models for the plasma transport to the substrate based on known properties of the cathode spot plasma jets are presented, as well as a description of current industrial practice