ICMCTF2005 Session B2-1: Arc and E-Beam Coatings and Technologies

Tuesday, May 3, 2005 8:30 AM in Room Sunset

Tuesday Morning

Start	Invited?	Item
8:30 AM	Invited	B2-1-1 Nanostructured Coatings and Polymer Surface Modfications by Filtered Cathodic Vacuum Arc and Plasma Immersion Ion Implantation (Plll) M.M.M Bilek, L. Ryves, B.K. Gan, D.R. McKenzie (University of Sydney, Australia) Increasingly, thin film coatings are used to optimize the surfaces of high-performance materials. Interactions of surfaces with their environment underpin a wide variety of applications, such as machining, implantable medical devices, and the operation of many types of sensors. Plasma based modification processes using highly ionized sources such as the cathodic arc allow us to create new materials often in an amorphous or glassy form and impart new properties to existing materials and surfaces. One of the important applications to be explored in this talk is the reduction of stress in the coatings, enabling them to adhere more strongly to the substrate. Introducing structure on the nanoscale can further enhance the toughness and other desirable properties of thin film coatings. There are many examples in nature where a material's most desirable properties are primarily a result of the meso-scale structure, which is on a scale larger than atomic dimensions but smaller than the wavelength of light. The synthesis of nanostructured coatings using modulation of ion energy and/or flux will be described.
9:10 AM		B2-1-3 High-Temperature Oxidation Resistance of Nanostructured Chromium-Silicon Nitride Coatings Obtained by an Hybrid Reactive Arc-Magnetron Deposition Process V. Rachpech, V. Chapusot (Laboratoire de Science et Génie des Surfaces, France); A. Billard (Ecole des Mines-Parc de Saurupt, France); J. Von Stebut (Laboratoire de Science et Génie des Surfaces, France) Nanocomposite coatings prepared by various vacuum techniques are known to allow a high level of hardness combined with a rather good high-temperature oxidation resistance. Among the methods available to produce such coatings, PVD processes are particularly attractive for mechanical parts of rather simple geometry. In this paper, we investigate the characteristics of Cr-Si-N thin films obtained by a hybrid arc-magnetron device, where Cr is evaporated by a conventional multiarc target and Si is sputtered by magnetron, in the presence of reactive Ar-N₂ mixtures. In a first part, we describe the experimental device and we give some trends about the process behaviour. In particular, the nitrogen enrichment discussed in relation with the structural and mechanical characteristics of Cr₂N - CrN films. In a second part, we investigate the influence of the discharge current dissipated on the silicium magnetron target on the chemical, structural and microstructural characteristics, as well as on internal stress of the films. Finally, the mechanical characteristics of the coatings such as hardness and brittleness, and their resistance properties to air oxidation at high temperature are presented in relation with their chemical composition and deposition parameters.
9:30 AM		B2-1-4 (TiAlV)N Films Grown by using a Repetitive Pulsed Arc Discharge A. Devia (Universidad Nacional de Colombia Sede Manizales, Colombia) (TiAlV) coatings were produced on 304 stainless steel samples. The system employed is a repetitive pulsed vacuum arc, which is managed automatically controlling the time of each pulse (in the order of 1 s). To grown the films, a target of TiAl₆V₄ is employed and the reaction chamber is filled with nitrogen at 2.7 mbar of pressure and 300 V of voltage. The films were studied by using a X Ray diffraction (XRD) technique, in order to identified the present phases, crystallite size, and micro-strain. Also the X photoelectron spectroscopy (XPS) is employed for calculating the chemical composition and stoichiometry. The morphology and thickness are determined by atomic force microscopy (AFM) and Scanning electron microscopy (SEM). The nanohardness of the films was studied using the nanoindentation technique which was implemented in the scanning probe microscopy (SPM).
9:50 AM		B2-1-5 Properties and Cutting Performance of (Ti,V)N Coatings Prepared by Cathodic Arc Ion Plating Y. Tanaka (Mitsubishi Materials Corporation, Japan); Y. Onishi (Mitsubishi Materials Kobe Tools Corporation, Japan); N. Ichimiya, K. Matsumura (Mitsubishi Materials Corporation, Japan) (Ti,V)N coatings were deposited on WC-Co substrates using a cathodic arc ion plating method. The structures and the compositions were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA). (Ti,V)N coating showed single phase cubic B1 structure with dense columnar microstructure typical for the cathodic arc ion plating. Wear resistant properties and friction coefficients of (Ti,V)N coatings against steel were evaluated by ball on disc test with elevated temperatures. (Ti,V)N showed friction coefficient of 0.51 against carbon steel at 600°C, which is lower than 0.91 of (Ti,Al)N. The high speed cutting performance was investigated by using coated carbide endmills and (Ti,V)N coatings showed greatly improved cutting performances on low hardness carbon steels. Wear mechanism and cutting characteristics were discussed with the structure and properties of the films.
10:10 AM		B2-1-6 Thin Films of Super-Hard Cubic Zr₃N₄ Stabilized by Stress M. Chhowalla, H.E. Unalan (Rutgers University) The deposition and characterization of super-hard cubic Zr₃N₄ thin films is described. The films are deposited using a novel but industrially viable modified filtered cathodic arc (FCA) method which allows unprecedented control over the plasma parameters which is essential for the deposition of the c- Zr₃N₄ phase. The Zr-N thin films deposited using the modified FCA have Zr₃N₄ stoichiometry and undergo a phase transformation from orthorhombic to cubic above a critical stress level of 9 GPa as determined by x-ray diffraction and Raman spectroscopy. The c- Zr₃N₄ films are significantly harder (~ 36 GPa) than both the orthorhombic Zr₃N₄ and ZrN films (~ 27 GPa). The c- Zr₃N₄ thin films are also transparent with an absorption edge at 1.6 eV. Our results indicate that the cubic phase is stabilized by the large stress and high temperature in the growth zone which create suitable thermodynamic conditions for stabilization of the meta-stable phase. The ability to deposit this material directly onto components as a thin film will allow its use in wear and oxidation resistant applications.
10:30 AM		B2-1-7 Structural and Mechanical Property of Si Incorprated (TiCrAl)N Coatings Deposited by AIP K. Yamamoto, S. Kujime, K. Takahara (Kobe Steel Ltd., Japan) To meet the demand of the cutting tool industry that harder work piece should be processed at higher cutting speed, hard coating has evolved to the one with complex composition, with ever increasing the hardness and the oxidation resistance. Previously we reported formation of superhard ternary nitride (Ti,Cr,Al)N coatings with high Al contents deposited by a new plasma enhanced cathode[1]. In this work, the effect of the Si incorporation on the mechanical properties of (Ti,Cr,Al)N coatings was investigated, using (Ti,Cr,Al)N coatings with different (Al+Si) ratios. These coatings were deposited by a AIP coater equipped with plasma enhanced cathodes. The deposition parameters such as substrate bias and substrate temperature were varied. The preferred texture of the (TiCrAlSi)N coating with (Al+Si)=0.6 changed from nearly random to (200) dominant as the substrate bias was increased up to 150V. A similar tendency concerning the preferred orientation was observed in case of (TiCrAlSi)N coating with (Al+Si)=0.65. However, peaks were broader and weak, suggesting the grain size was smaller at higher (Al+Si) ratio. Further change in crystal structure (cubic-hexagonal) was investigated against substrate bias and deposition temperature. The hardness values measured by the nano-indentation technique were nearly homogeneous over the substrate bias range examined that were about in the range of 25 to 27 GPa. The relationship between (Al+Si) ratio and oxidation resistance also will be presented which has significant influence on the high speed cutting performance. [1] K. Yamamoto et al. Surf. Coat. Technol. 174-175(2000)620.
10:50 AM		B2-1-8 Deposition of Superhard TiAlSiN Thin Films by Cathodic Arc Plasma Deposition S.K. Kim (University of Ulsan, Korea) Thin films of TiAlSiN were deposited on SKD11 tool steel substrate using Ti and AlSi targets by a cathodic arc plasma deposition system. The influence of the nitrogen pressure, AlSi arc current, bias voltage, deposition temperature on the mechanical and the structural properties of the films were investigated. The hardness of the film decreased with the increase of nitrogen gas pressure. The hardness of the film increased with the increase of AlSi arc current and the bias voltage. The hardness of the film reached 48GPa at the deposition temperature of 300 ⁰C and decreased with a further increase of the temperature. Wear and scratch tests were performed on thin films deposited in various conditions. The critical load of the films was above 50 N. Cutting tests of end mills deposited with these films showed superior wear resistance.