ICMCTF2008 Session B2: Arc and E-Beam Coatings and Technologies

Friday, May 2, 2008 8:00 AM in Room Golden West

Friday Morning

Time Period FrM Sessions | Abstract Timeline | Topic B Sessions | Time Periods | Topics | ICMCTF2008 Schedule

Start Invited? Item
8:00 AM B2-5 Chromium and Titanium Film Deposition Using a Hot Refractory Anode Vacuum Arc Plasma Source
I.I. Beilis, A Shnaiderman, R.L. Boxman (Tel Aviv University, Israel)

The radially expanding plasma jet generated in a Hot Refractory Anode Vacuum Arc (HRAVA) was used to deposit thin chromium and titanium films on glass substrates. The arc was sustained between a water-cooled cylindrical cathode and a non-consumed cylindrical tungsten anode seprated by a 10 mm gap, for time periods up to 120 s, operating with a current (I) of 200 - 300 A. The chromium cathode had a 30 mm diameter and 20 mm height, and was used with 32 mm diameter, 30 mm high anode. The titanium cathode was 60 mm diameter and was used with a 60 mm diameter anode.

Thin films were deposited on glass substrates exposed to the anodic plasma. A mechanical shutter controlled the deposition onset and exposure duration time. The distance from the arc axis to the substrate (L) was varied between 80 and 110 mm. The film thickness was measured by a profilometer, and macroparticle (MP) presence on the coating surface was examined by optical microscopy. It was found that the deposition rate of Cr films increased with arc current and reached ~ 1.4µm/min at I=300A, L=80mm. The total MP flux was less then 1mm-2min-1 for I=300A, L=110mm. The deposition rate of Ti films reached 1µm/min at I=200A, L=80mm.

8:20 AM B2-1 The Structure and Properties of Deposits Produced by EB- and Vacuum Arc PVD Techniqus
A.V. Demchyshyn (Institute of Problems in Material Science, NANU, Ukraine, Kiev, Ukraine)
The present paper gives an overview of the structures and mechanical properties of metallic and ceramic electron beam and cathode arc deposits as a function of technological parameters (a substrate temperature, deposition rate, negative substrate bias). More complex condensate systems synthesized by both techniques are also discussed. They include dispersion-strengthened and multilayered deposits with different combinations of metallic matrices, strengthening phases and alternating layers. The structure and mechanical properties of these composites are presented as a function of volume fraction of strengthening phase in metallic matrix or a lamina thickness and components ratio in multilayered condensates. The obtained results show a possibility to control within a wide range structures and mechanical properties of deposits.
9:00 AM B2-3 The Structure and Properties of Ti, Ti36Al and Ti/Al Deposits Produced by Cathodic Arc Evaporation
A.V. Demchyshyn (NANU, Ukraine); V.S. Goltvyanytsya, S.K. Goltvyanytsya (Real Ltd., Ukraine); L.D. Kulak, O.A. Tokarev, G.A. Avtonomov (NANU, Ukraine)
The Ti, Ti36Al and Ti/Al coatings on stainless steel and copper substrates have been produced using a non-filtered vacuum arc deposition technique. The surface morphology, cross-section fracture and microstructure of deposits were observed as a function of substrate biasing, cathode temperature and laminar thickness using scanning electron microscopy (SEM) JEOL 733. Transmission electron microscopy (TEM) JEOL 200 was used for observing of the multilayered Ti/Al deposits microstructure planar view. The coating thickness was 40-100 µm. The obtained results showed a great influence of process parameters on the structure and mechanical characteristics of studied vacuum arc deposits.
9:20 AM B2-4 Deposition of Thick Cr-Cu Coatings Using Twin Crucible Electron-Beam Physical Vapour Deposition
K. Kanakis, A. Leyland, A. Matthews (University of Sheffield, United Kingdom)

Plasma-assisted Electron Beam Physical Vapour Deposition (EBPVD) processing may in some be cases more attractive than sputtering for commercial applications, as it offers the potential for lower running costs and higher maximum deposition rates. In this paper, we deposit Cr-Cu based coatings using EBPVD. Due to the low miscibility of Cr and Cu (the former with or without an interstitial solid solution of N), predominantly metallic nanocomposite coatings with high resilience and toughness and a hardness close to that of ceramic coatings (>15GPa) can be produced by magnetron sputtering, at thicknesses of around 3-5µm.

One of the main advantages of a metallic coating (in contrast with a typical ceramic coating) is less coating internal stress, which can result in improved resilience under load and better adhesion to the substrate. Nanocomposite coatings that are predominantly metallic are therefore excellent candidates to be deposited with much higher thicknesses (>10µm) and (by EBPVD) at high deposition rates. Such thick coatings could have numerous advantages over standard, thin, vapour deposited coatings in applications where wear, corrosion and oxidation resistance are required which, at the moment, can be satisfied only by other processing techniques such as electroplating and thermal spraying, where desirable combinations of materials, composition and structure are relatively limited and hardness, adhesion and toughness are relatively low.

Several techniques are employed for coating characterisation, such as X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Hardness and wear performance have been evaluated for the deposited films by means of nanoindentation, reciprocating sliding and ball-on-plate impact tests, respectively. The corrosion resistance is investigated by potentiodynamic testing, whilst the high temperature oxidation resistance is examined by means of thermo-gravimetric analysis, X-ray diffraction and scanning electron microscopy.

9:40 AM B2-6 Filtered Laser-Arc: A New Technology for Deposition of Smooth ta-C Films
H.-J. Scheibe, C.-F. Meye (Fraunhofer-Institut für Werkstoff- und Strahltechnik, Germany)

Vacuum arc deposition technology for film deposition is established for industrial deposition of hard coatings as TiN, ZrN, TiAlN. A disadvantage of this deposition method is that great particles and droplets are emitted and will be incorporated in the deposited layers. By means of pulsing the arc discharge the particle emission can be reduced. But, there smoothness is not comparable with films are deposited by sputtering. For deposition of thin, smooth films by arc, magnetic filter equipment has been applied successfully separate these particles from arc plasma. The industrial using of such a technique for the deposition of thicker films is unproductive due the high loss of deposition rate. Alternative a mechanical gladding of arc deposited thick films often has been preferred. We present a new developed simple filter arrangement for pulsed arc deposition (Laser-Arc). Only a simply additional absorber electrode connected to an electrical potential positive with respect to the plasma is used instead of a different number of magnet coils as usual in the applied classical filters. The electrode is placed in front of the arc cathode (roll) at an obliquely inclined angle which takes account of the divergence of the plasma flow. On this way the charged plasma particle will be separated from macro- and micro-particles and will be deflected for deposition on the substrates. The advantages of this kind of filter are unlimited linear extension of deposition area, simple construction and high efficiency. The transparency of the filter has been measured to be more than 60% in the case of super hard carbon (ta-C) film deposition. A changing of the surface roughness of standard polished silicon wafers could not be observed up to a film thickness of more than 2 microns.

Besides the demonstration of the principle of this new filter technique, first results of thick ta-C film deposition and its potential of the up scaling for industrial using will be discussed.

10:20 AM B2-8 Influence of Hollow Cathode Plasma on AlCrN-Thin Film Deposition With Vacuum Arc Evaporation Sources
M.H. Holzherr, M.F. Falz, T.S. Schmidt (VTD Vakuumtechnik Dresden GmbH, Germany)
In order to provide a sufficient wear protection on tools, the substrates can be coated with different hard material layers. In the standard hard material coating process of the DREVA 600 coating plant two hollow cathode (HC-) plasma sources are used for the in situ pre-treatment of the substrates i.e. for electron impact heating and Ar-ion etching. Six round vacuum arc (VARC-) sources operate as metal evaporation sources. If working temperature exceeds a defined valuation the important hardness of thin film is reduced strongly. This effect depends on coating materials. For the standard TiAlN-coating the maximum operating conditions are therefore limited to 850°C. Nowadays for high speed and dry or low lubricant cutting applications no decrease of hardness at high working temperatures about 1100°C is allowed. Aluminium-Chromium-Nitride (AlCrN) has extended operation conditions through its high oxidation resistance. A further improve of AlCrN-thin film coatings through parallel operation of the hollow cathode plasma sources with arc evaporation sources will be shown. By means of optical emission spectroscopy (OES-) measurements it can be demonstrated that the additional hollow cathode plasma provides an increase of excitation and ionisation degree of the evaporated aluminium in the advanced AlCrN deposition process. The HC-plasma influences on AlCrN-thin film properties, the oxidation behaviour and hot hardness after annealing experiments will be shown as well as results of drill tests.
10:40 AM B2-9 Pulsed Arc Evaporation and the Influence of the Pulse Mode on Al-Cr-O Layer Properties
J. Ramm, M. Ante, D. Kurapov, O. Massler, B Widrig (OC Oerlikon Balzers AG, Liechtenstein); M. Doebeli (Paul Scherrer Institute and ETH Zurich, Switzerland); A Dommann (Centre Suisse d’Electronique et de Microtechnique Neuchâtel, Switzerland); A Neels (Institute of Microtechnology University of Neuchâtel, Switzerland); J Thomas (IFW Dresden, Germany)
Pulse enhanced electron emission (P3eTM) is a PVD technology for the synthesis of metal oxides utilizing cathodic arc evaporation in which the arc current can be pulsed. The operation of the arc sources with pulse current is a new approach in oxide deposition and contributes to the process stability. Here it is investigated how the different pulse modes influence the layer properties. Different parameters for the pulsed operation of the arc sources were chosen. Pulse frequency, pulse current and pulse voltage in combination with different magnetic fields of the arc sources are compared with the standard DC operation of the arc source. Based on the optical emission spectra during pulsed deposition, enhanced activation of the evaporated material and the reactive gas was measured. The influence of the different pulse modes was investigated in more detail for Al-Cr-O layers with special emphasis on layer morphology (SEM), stoichiometry (RBS) and crystal structure (XRD). Phases and the formation of solid solutions in this material system were characterized on cross sections by transmission electron microscopy. Micro hardness, layer stress and thermal stability of the coating are compared for the different pulse modes. Cutting tests of mono and multi layer oxide coatings were performed to illustrate the performance for cutting tool applications.
Time Period FrM Sessions | Abstract Timeline | Topic B Sessions | Time Periods | Topics | ICMCTF2008 Schedule