Multi-arc ion plating is the direct evaporation of metal on the solid cathode target by means of arc discharge. The evaporant is an Ion of a cathode material released from a cathode arc glow point so that it can be deposit a thin film on the substrate surface.
Vacuum ion plating was proposed by D. M. Mattox in 1963 and began the experiment. In 1971, Chamber et al. published electron beam ion plating technology. In 1972, B reported the reaction evaporation plating (ARE) technology, and made TIN and TIC superhard films. In the same year, MOLEY and SMITH applied hollow cathode technology to coating. In 80s twentieth Century, multi arc ion plating and arc discharge high vacuum ion plating appeared in China, and the ion plating reached industrial application level.
Ion plating is performed in a vacuum chamber by gas discharge or partial ionization of evaporant, the evaporation or reactant deposition on the substrate, while bombarding effect by gas ions or evaporant particle, the evaporation or reactant deposition on the substrate. Ion plating combines glow discharge, plasma technology and vacuum evaporation, which can not only improve the film quality obviously, but also enlarge the application scope of the film. The advantages of the film are strong adhesion, good diffraction and extensive membrane material. D.M. first proposed the principle of ion plating, which working process is:
● The vacuum chamber is pumped to the vacuum degree above 4 x 10 (-3) Pa, and then connected to the high voltage power supply and establish a low-temperature plasma region of low-pressure gas discharge between the evaporation source and the substrate.
● The substrate electrode connected to 5KV DC negative high voltage to form a glow discharge cathode.
● The inert gas ions produced in the glow discharge zone are accelerated by the electric field in the dark area of the cathode and the surface of the substrate is bombarded and cleaned.
● In the coating process, the heating makes the material vaporized, the atoms enters the plasma area, which collides with the inert gas ions and electrons and a few part of the ionization is produced.
● The ionized ions and gas ions bombarded the coating surface with higher energy, which improved film quality.
Multi-arc ion plating is different from the general ion plating, which is using arc discharge to instead of the traditional ion plating glow discharge deposition. In short, the principle of multi-arc ion plating is to use the cathode target as the evaporation source to evaporate the target material by arc discharge between the target and the anode shell, so that the plasma is formed in the space, and deposition on substrates.
● The plasma is generated directly from the cathode without a molten pool. The cathode target can be arranged in any direction according to the shape of the workpiece, so that the fixture is greatly simplified.
● The energy of the incident particle and the density of the film is high, the strength and durability are good, and the excellent adhesion strength.
● High rate of ionization, generally up to 60% to 80%.
● From the application point of view, the deposition rate is fast.
● At high power, it is necessary to produce a boiling point, which affects the quality of the coating.