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The method of laser-sustained arc ignition.

Die Methode für Lasergestützte Bogenzündung
 
: Siemroth, P.; Scheibe, H.J.

:

IEEE transactions on plasma science 18 (1990), Nr.6, S.911-916 : Abb.,Tab.,Lit.
ISSN: 0093-3813
Englisch
Zeitschriftenaufsatz
Fraunhofer IWS ()
Laser-Arc; laser-induced film deposition; laserinduzierte Schichtabscheidung; PVD-Technik; PVD-technique; vacuum arc deposition; vacuum arc ignition; Vakuumbodenzündung; Vakuumbogenbeschichtung

Abstract
The method of laser-assisted vacuum arc deposition (laser-arc) was developed to produce effectively high-quality coatings, especially multilayer coatings with a reduced number of droplets. The efficiency of this method depends mainly on the ignition probability of the vacuum arc discharges. In the present paper the process of arc initiation by laser irradiation will be studied and the influencing factors such as power density of laser irradiation will be studied and the influencing factors such as power density of laser irradiation, target material, and electrode configuration will be discussed. It will be shown that a high ignition probability (p bigger than 50 %) on such coating materials as Ti, TiC, TiN and C may be guaranteed with a laser power density of about 10high8W/qcm, which can be achieved with a low-cost Nd-YAG pulse laser. Measurements of the plasma current preceding the arc ignition and microscopical investigations of the erosion pattern caused by the laser irradiation su ggested that the process of plasma-sustained arc ignition (unipolar arcing) plays an important role during the buildup phase of the vacuum arc discharge.

: http://publica.fraunhofer.de/dokumente/PX-23718.html