Discharge characterization and technological application of an arc ion plating with a hollow cathode vacuum arc

In an effort to reduce macroparticle defects in arc ion plating, a hollow cathode vacuum arc was added to an arc ion plating deposition chamber, so that the discharge from the hollow cathode vacuum arc was between the target and the substrate. AlTiN coatings were deposited using this technique (hollow cathode vacuum arc enhanced arc ion plating or HCVA-AIP) on high-speed steel substrates, and analyzed using scanning electron microscopy and X-ray diffraction. The hollow cathode vacuum arc was found to reduce the number and size of macroparticles in the deposited coatings and to increase the deposition rate. The hollow cathode vacuum arc also reduces the arc ion plating target voltage, by up to 29% (to 12 V) under the conditions studied here. Using this technique, the rate of Al ionization in the target is enhanced, resulting in the formation of AlN in the coating. This effect is strengthened at a higher hollow cathode vacuum arc discharge current.