ICMCTF2002 Session B1-1: PVD Hard Coatings and Technologies

Thursday, April 25, 2002 8:30 AM in Room Golden West

Thursday Morning

Start	Invited?	Item
8:30 AM	Invited	B1-1-1 Efficiencty of Magnetic Plasma Filters I. Aksenov, V.E. Strelnitskij, V.V. Vasilyev, D. Yu. Zaleskij (NSC Kharkov Institute of Physics and Technology (KIPT), Ukraine) The first magnetic filter for cleaning macroparticles from vacuum-arc plasma flows was developed at the Kharkov Institute of Physics and Technology in the mid 1970’s. Design of this apparatus was motivated by the desire to synthesize high quality DLS films. The curvilinear filter version is currently the most prevalent both in laboratory and industrial practice. But the complexity, low efficiency and less than ideal filtering of the apparatus preclude them from being used more widely. Research and development performed by the Kharkov group of physicists are delineated in this work. Resent experiments on defining features of curvilinear plasma filters and their dependence on their electro-magnetic and geometric parameters are described. The work demonstrates the possibility and advisability of improving and optimizing the filtering, and predicts through computer simulation macroparticle motion along the plasma duct, taking into consideration multiple rebounds of particles from the walls. The results of computations performed for some well know magnetic filters are presented. The proposed method of estimating the efficiency of macroparticle flow suppression in combination with the computation of magnetic field distribution in the transport channel of the filters permits optimizing the system by two criteria: (I) maximum removal of macroparticles from plasma and (II) minimum loss of the ion component of the plasma. Curvilinear and rectilinear filters were studied and tentatively optimized using these methods. Examples of present application and also perspective use of filtering techniques are presented. Some alternative versions of magnetic plasma filters, including the device with axial-to-radial transformation of plasma flows, are described. The latter is characterized by the highest transport efficiency of any other known filtering system. The principle of this apparatus is proposed for use in a new filtering system for treating plane surfaces of large areas including rolled materials.
9:10 AM		B1-1-3 Advanced Coating Architectures by Application of Pulsed and Filtered Arc Ion-Plating A.N. Panckow (Otto-von-Guericke-University Magdeburg, Germany); J. Steffenhagen, F. Lierath (Otto-von-Guericke Universität Magdeburg, Germany) Wear resistant coating systems for cutting tools were designed by the application of an ion-plating technology on the base of filtered arc evaporation combined with pulsed plasma surface treatment. The deposition of the hard coatings under pulsed ion bombardement of a macroparticle free plasma stream resulted in an improved microstructure of the multilayered coating systems in compare with conventional arc deposited coatings. The coating architecture of these multilayered systems, designed according to the principle of stacked functional layers, was optimized under the aspect of increasing the life time of the coated cutting tools. Both laboratory and industrial tests were performed with HSS- and carbide cutting tools for several applications. The characteristic features of microstructure investigated by electron microscopy methods will be discussed. Further prospects for various other applications of the mentioned coating technology and corresponding coating architectures will be shown.
9:30 AM		B1-1-4 Properties and Cutting Performance of Ternary Nitride Coatings Deposited by New Plasma Enhanced Arc-Cathode K. Yamamoto, T. Sato, K. Takahara, K. Hanaguri (Kobe Steel Ltd., Japan) Ternary metal nitrides were synthesized by cathodic arc ion plating process (CAIP) with a new type of plasma enhanced arc evaporation source. The improvement of the new arc-cathode was so achieved by the optimization of the magnetic field geometry using computer aided magnetic field analysis that augment the arc spot motion on the cathode target surface and ionization of the gaseous reactants in the plasma. A new ternary system of metal nitrides for wear resistant applications was developed for the this plasma enhanced cathode and their structural and mechanical properties were investigated. These coatings were deposited from ternary alloy targets under nitrogen atmosphere (PN₂=2.66 Pa) and substrate biases between -50 and -200 V were applied. The operating arc current was typically in the range of 100 to 150 A. The results on hardness measurements showed that the hardness of the new ternary coating reached approximately HV 3500, which is promising for the cutting applications, whereas hardness below HV 2500 was realized in the case of coatings deposited by the conventional arc-cathode. The onset temperature of oxidation was more than 1000 degree C for the new ternary coating, whereas 850 degree C was realized in the case of conventional TiAlN binary coating. Primary cutting tests against hard (AISI H13, HRC 50) and soft work piece (carbon steel, HB220) showed significant improvement in wear of tool, resulting in much prolonged tool life.
9:50 AM		B1-1-5 Advanced Coating Technology, Tribological Performance and Characterization of Hard Coatings Produced by Cathodic Arc Deposition H. Curtins (Swiss-Plas.com AG, Switzerland); J.H. Sanders (U.S. Air Force AFRL/MLBT); A.L. Korenyi Both (PVT, Plasma and Vacuum Technologies LLC); H.M. Gabriel (PVT, Plasma und Vakuum Technik GmbH, Germany); H. Mathies (New-Plas.com AG, Switzerland); J. Cip (Coating Technologies CZ, Czech Republic) The United States Air Force and manufacturing industry benefit tremendously from advanced coatings on cutting tools, forming tools, molding and precision wear components. The challenge has always been to create advanced coatings with broad industrial application and industrial viability. The PVT M2/Arc Development Program has resulted in the establishment of an industrial Physical Vapor Deposition (PVD) technology, which produces hard and tribological coatings with exceptional performance. This new PVD-Arc deposition platform is marked by technological advancements co-existing with excellent economic and environmental consideration in an industrial package. We detail the novel technology and its benefits from an operational standpoint and also specific coating and application properties. Highlighted are process control considerations, specifically the vacuum environment, interface formation, arc control, thermal management and multilayer and multi-component technology. Data is presented on coating properties as analyzed by testing for: hardness, adhesion, friction -wear, calot grind and coating morphology via optical and scanning electron microscopy. Tool performance testing based on this novel technology is also presented.
10:10 AM		B1-1-6 Microstructure and Mechanical Properties of Cathodic Ion Plated (Al,Ti)N Coatings K. Sato (MMC Kobelco Tool Co., LTD., Japan); N. Ichimiya (Mitsubishi Materials Corporation, Japan); A. Kondo, Y. Tanaka (MMC Kobelco Tool Co., LTD., Japan) Cathodic arc ion plated (Al,Ti)N coatings were deposited on WC-Co substrates by several bias voltages. The residual stress of the films, measured by the X-ray diffraction (XRD) 2θ-sin²φ method, was found to vary significantly by the change of negative bias voltages. The composition and microstructure of the films were investigated by electron probe micro analysis (EPMA) and transmission electron microscope (TEM) and these were also changed by bias voltages. These were related to the strains of the films introduced by the ion bombardment and could be evaluated by the peak shifts and half-value widths of XRD profiles. At higher bias voltage, the films were mainly composed by granular structures with the size of 100nm. On the contrary, at the lower voltage, composed by columnar structures with the same size. Carbide drills deposited (Al,Ti)N coating by low bias voltage (V_B=-20V) shows much better cutting performance in the machining of carbon steel, compared with high bias voltage (V_B=-100V). The relationship between the properties of films and cutting performances are investigated and discussed.
10:30 AM		B1-1-7 High Energy Pulsed Cathodic Arc Evaporation of Cr-N on Aluminum Substrates T.B. Dennin, J.J. Moore (Colorado School of Mines); J.R. Treglio (Cutting Edge Products) Cr-N films were deposited on 7075-T6 aluminum substrates at low temperatures (below 200 °C) by Cathodic Arc Evaporation (CAE) coupled with a Hyper-Ion (HI) source. Taking advantage of the high degree of ionization of material emitted by CAE, the HI source applies a short, high voltage pulse (5-25 kV for 1 µs at a frequency of 1-10 kHz) to the substrate, while a constant d.c.bias is also applied to the substrate. The ions from within the plasma sheath are further accelerated toward the substrate by the high voltage pulse and their resulting collision with the substrate surface is intense enough to modify the substrate/coating interface. The focus of the work is to study the microstructure at the subtrate/coating interface and the influence the interface modification has on film toughness and adhesion.
10:50 AM		B1-1-8 Deposition of Aluminum Oxide Thin Films by Filtered Cathodic Arc Technique and Study of its Tribological Properties S.J. Dixit, A.K. Rai, R.S. Bhattacharya (UES, Inc.) Recently, Filtered Cathodic Arc technique has evolved as an important tool for the realization of various industrial coatings such as transition metal nitrides, carbides, oxides, diamond like carbon (DLC) etc. In particular, this technique is best suited for high rate deposition of oxide coatings. In the present study, we will be reporting the process conditions and characteristics of Aluminum Oxide coatings deposited at various temperatures and bias voltages. Transmission Electron Microscopy (TEM) is employed to study the film microstructure and Auger Electron spectroscopy (AES) for atomic composition. Preliminary TEM studies indicate the formation of nanocrystalline nη-Al₂O₃ phase. Tribological properties such as wear and friction coefficient of these coatings on TiAlN coated discs will be presented.
11:10 AM		B1-1-9 Investigation of Non-hydrogenated DLC:Si Prepared by Cathodic Arc O.R. Monteiro (Lawrence Berkeley National Laboratory); M.P. Delplancke-Ogletree (Universite Libre de Bruxelles, Belgium) Non-hydrogenated DLC films (ta-C) have been extensively studied and are used for a variety of wear related applications. Alloying DLC with refractory metals and other elements have been shown to be promising techniques to overcome some of the problems associated with pure DLC, such as excessive level of intrinsic stresses and high-temperature stability. The microstructure of DLC:Me in general consists of crystalline metal carbides dispersed in a DLC matrix. In contrary, DLC:Si has an amorphous structure. We have used filtered cathodic arc to prepare DLC:Si up to 4% Si, and have characterized their structure and bonding using microscopy (TEM) and spectroscopy (XPS, NEXAFS). The effect of Si in changing the bonding configuration of the C network is discussed. The microstructure is then correlated to hardness and friction measured by nano-indentation and micro-wear.
11:30 AM		B1-1-10 Microscale Defects in Arc Deposited Coatings and Their Effect on Macro Dissolution Behavior In Aluminum Die Casting V. Joshi, A. Srivastava, R. Shivpuri (The Ohio State University); R.S. Bhattacharya, S.J. Dixit (UES, Inc.); D.G. Bhat (University of Arkansas) Simplified controlled laboratory tests are often used to study fundamental wear and failure mechanisms, and to model the behavior of coatings and surface treatments in actual production. However, when the results of these laboratory tests are used to predict the behavior of these coated surfaces in actual production dies the correlations are not strong. This is paper examines the issues involved with scaling the laboratory data to actual production, and discusses the effect of differences in geometry (size, corners), process conditions (flow direction, thermal gradient, stresses) and production practices (maintenance, handling) on the tribological behavior of coated surfaces. Comparative evaluation of selected PVD, CVD and surface treated coupons in laboratory dip and thermal cycling tests, and in selected production beta sites at die casting companies form the basis of this discussion.
11:50 AM		B1-1-11 Magnetic Field Dependent Plasma Chemistry Variations in Reactive Pulsed Discharges J. Rosen (Linköping University, Sweden); A. Anders (LBNL, Berkeley); J.M. Schneider (RWTH-Aachen, Germany) The effect of a magnetic field on the plasma chemistry and pulse-to-pulse fluctuations of cathodic arc ion charge state distributions in a reactive environment were investigated. The plasma composition of pulsed aluminum plasma streams generated from cathodic arc spots was measured by time-of-flight charge-to-mass spectrometry. The relative standard deviation for the average concentrations of Al⁺, Al₂⁺ and Al₃⁺ was increasing with an increased magnetic field. These findings are qualitatively consistent with the model of partial local Saha equilibrium describing the transition from equilibrium to non-equilibrium of the expanding plasma. The results are of fundamental importance for the evolution of the structure of films deposited by reactive cathodic arc deposition.