Laser-Arc technology for industrial hard coating deposition

The Laser-Are method represents a pulsed vacuum deposition where the are discharge is ignited by short laser pulses. Owing to the short burning times of the single arcs, the erosion is restricted to the immediate neighbourhood of the ignition point, the laser focus. Hence, the cathode spots may be displayed on the cathode surface according to the displacement of the focus position. In this way, the drawbacks of conventional are technology such as local overheating and emission of microparticles are essentially reduced. The Laser-Are has been scaled up from the laboratory level to an industrial prototype. This fully computerized equipment allows the deposition of hydrogen-free diamond-like carbon films of hardness up to 80 cpa with a growth rate of up to 0.2 mu m min(-1). Owing to their low friction and high wear resistance, these films are especially suitable for sliding elements. Such different materials as alloyed and non-alloyed steels, hard metals, copper, aluminium alloys or brass were coated and demonstrated good adherence. The process runs below 100 degrees C and allows the deposition on temperature-sensitive materials such as polymers. New fields are opened by the preparation of nanometer-multilayers which are performed by means of this Laser-Are equipment without any loss in effectivity. (C) 1997 Elsevier Science S.A.