Film deposition by laser-induced vacuum arc evaporation

The method of laser-induced arc evaporation (laser-arc) combines the advantages of the laser-pulse vapor deposition (LPVD) technique with the technologically utilized vacuum arc evaporation (VAD). Laser-arc may be effectively and precisely controlled like LPVD, but its energy efficiency and properties of the deposits equal those obtained by the vacuum arc. In the present paper the latest results of the study of the deposition process and the technological development of the laser-arc are presented. Studies of the influence of arc current on film deposition were carried out for different materials (Ti,TiC,C). On the basis of these results definite mutlilayered structures are prepared. As an example, a Ti/TiC multilayer system with 25-nm single layers is described. Results of structural and chemical analysis by means of AES spectroscopy are presented. It could be shown that diamond-like carbon film with a refractive index in a range of between 2.05 and 2.5 can be deposited effectively

DLC-Schichtabscheidung mit dem Laser-Arc und Eigenspannungsuntersuchungen

The Laser-Arc is a controlled pulsed arc plasma source combining advantages of the pulsed laser deposition (PLD) technique with the high energy efficiency of a vacuum arc (VAD). The influence of deposition temperature on DLC-film properties will be shown by the results of mechanical and optical studies. Elastic modulus (E) was measured by means of ultrasonic surface waves. E-values up to 230 GPa were obtained for substrate temperatures bellow 150 Cel. The very small modulus for T > 150 Cel suggests a drastic decrease of sp (exp 3)/sp (exp 2) onding ratio in the amorphous DLC structure. These results correlate with optical studies, by means of ellipsometry and the behaviour of the complex refractive index. The optical absorption at 10.6 micrometres ranges from 200 to 900 cm (exp -l) and depends on the film thickness and on the substrate material. The results demonstrate that the Laser-Arc is suitable for the preparation of DLC-coatings with optical quality

Tribological characterization of hard carbon films prepared by laser-arc

Hard diamond-like carbon films were deposited on silicon wafers and hardened steel substrates using the method of laser-induced, laser-pulsed and laser-guided vacuum arc evaporation (LASER-ARC). The deposition was carried out in a vacuum of approximate 10 high -4 Pa with an arc repetition frequency of 100 Hz, a peak current of 500 A and a pulse duration of approximate or equal 37 Mys. After substrate cleaning by an Ar+ - ion bombardment films were prepared at different deposition temperatures (50 degree C smaller than Ts smaller than 500 degree C) up to a thickness of approximate 0.5 Mym. The tribological behavior of as deposited C-films were studied by means of a vibration wear technique with a steel ball (AISI 52100) as a conterbody. To check the effect of water content of surrounding air test were performed in air of ambient temperature but varied relative humidity. From the in situ measurement of friction and wear the tribological life time of films were determined. From the wear s can at the end of a test and additional profilograms the wear of the ball and that of the disk were calculated separately. The results demonstrate that a very good wear resistance and a low coefficient of friction is found for special conditions of the coating process by Laser-Arc. However the friction and wear of all coatings was increasing strongly in dry air. These results are the basis of further investigation to modify the coating process by Laser-Arc

Superharte amorphe Kohlenstoffschichten

Super-hard amorphous carbon layers are new layers with superior sliding and wear protective properties. With the assistance of high-performance process and plant engineering, thin-layer technology becomes attractive for numerous new application. With the Laser-Arc method, for instance, superhard amorphous carbon layers can be produced for industrial use

DLC and metallic nanometer multilayers deposited by laser-arc

The method of laser-induced vacuum arc (laser-arc) combines the good controllability of pulsed laser deposition with the high efficiency of a vacuum arc technique. One advantage of this technique is the essential reduction of droplets allowing the deposition of high-quality amorphous carbon films. These hydrogen-free films with very high hardness up to the superhard range exhibit excellent wear resistance and low friction. In the present paper, another advantage of the laser-arc is demonstrated, i.e. the possibility of depositing multilayer coatings down to the nanometer level of each individual layer thickness with high efficiency and high accuracy. These possibilities open new ways to overcome the principal problem of hard PVD coatings, i.e. the high internal stress which restricts the film thickness. Multilayer systems of Al-C and Ti-C with systematic variations of single layer thickness and thickness relationship were analysed by electron microscopy and Auger electron spectroscopy. The Young's moduli were measured by the non-destructive ultrasonic surface wave method (US-SAW). The alternating hard and ductile layers allowed a remarkable relaxation of the internal stresses. Furthermore, the growth of the particle induced defects (droplets) could be strongly reduced

Laser-Arc - A new method for preparation of diamond-like carbon films

The method of laser-induced vacuum arc evaporation (laser-arc) combines the advantages of laser pulse vapor deposition (LPVD) and the widely used vacuum arc evaporation. When controlled effectively and precisely, it combines the pulse deposition of LPVD with the high energy efficiency of vacuum arc evaporation. The properties of the deposits are similar to those obtained by vacuum arc evaporation, characterized by plasma-sustained ion bombardment. Plasma-deposited films adhere well to the substrate and have a dense microstructure. In this paper, the latest results of the technological development of the laser-arc method are presented. Investigations of arc ignition and film deposition were carried out for different materials, in particular carbon. The first results of diamond-like carbon film deposition are presented. Deposition rates of about 5 nm s-1 can be achieved. The results of structural and chemical analysis by transmission elctron microscopy and electron diffraction are presen ted. It is shown by ellipsometry that diamond-like carbon films with a refractive index in the range 2.1-2.5 can be deposited effectively