ICMCTF2001 Session EP-1: Symposium E Poster Session
Tuesday, May 1, 2001 5:00 PM in Room Atlas Foyer
Tuesday Afternoon
Time Period TuP Sessions | Topic E Sessions | Time Periods | Topics | ICMCTF2001 Schedule
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EP-1-1 Mechanical and Tribological Wear Properties of Nanograined Magnetron-Sputtered Metallic Coatings Based on Chromium.
A.D. Wilson, C. Tsotos, A. Leyland (Research Centre in Surface Engineering, United Kingdom); A. Matthews (University of Hull, United Kingdom) There is increasing interest in the development of nanograined ('nanocomposite') coatings based on coherent or semi-coherent binary mixtures of ceramic/amorphous or ceramic/metal phases. It is claimed that anomalous changes in hardness and elastic modulus can be created, similar to those seen in nanolayer heterostructures ('superlattice' films), whereby improvements in mechanical and tribological wear properties can be obtained. One of the main benefits of such films is a less stringent requirement for precise deposition rates on complex-shaped industrial components, since, unlike superlattice films, there is no need to create an exact nanolayered structure. This has commercial relevance in widening the range of techniques by which such coatings can be deposited, to include alternative PVD methods, such as arc and electron-beam evaporation, as well as thermal spraying or electrodeposition. Recent work at RCSE on the ternary and quaternary Ti(-Al)-B-N phase systems, has shown that ceramic/ceramic, ceramic/amorphous, ceramic/metal - and even metal/metal - phase combinations can be beneficial in tailoring the hardness and elastic properties of coatings, to suit particular wear conditions. Similarly, the behaviour of chromium-based PVD coatings can be adjusted by synthesising appropriate mixtures of metallic and/or ceramic phases, to give improved performance in different applications. This work examines the behaviour of chromium-based (predominantly metallic) films, with small additions of metallic and/or non-metallic elements to refine coating microstructure. Hardness, elastic modulus and wear test measurements (reciprocating-sliding and impact wear with a ball-on-plate Hertzian contact geometry) are made and discussed with regard to the implications for industrial applications where, the close matching of the coating/substrate interfacial elastic properties may be of more importance than is the extreme hardness which other researchers claim. |
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EP-1-2 Tribological Properties of Hard Coatings Subjected to Ultrasonic Vibration
M. Murakawa, H. Noguchi, M. Jin (Nippon Institute of Technology, Japan); S. Kataoka, K. Kato, A. Motoi (The Tokyo Metropolitan Industrial Technology Research Institute, Japan) From the viewpoint of protection of the environment and/or reduction of the production costs, decrease in use of lubricants in the cutting and/or metal working processes has been demanded strongly due to the severe load they impose on the environment. In an effort to achieve such goals, use of chlorine-free and/or low viscosity lubricants as the environment friendly processing oil and even development of dry processes have been investigated as the countermeasure. In order to achieve the purpose, however, it is necessary either to improve the wear-resistance property of a tool or to develop a different lubricating method other than just applying the working oil because of inevitable low lubricating capability that the countermeasure brings about. For the improvement of wear-resistance of a tool, the coatings of carbonic hard films such as diamond or DLC, or ones composed of other materials such as TiAlN and MoS2 are effective on one hand. On the other hand, use of ultrasonic vibration applied to tools has been found very effective as an alternative and/or additional lubricating method. However, the mechanism involved is little known. Thus, in this study, tribological characteristics of the above-mentioned hard coating films subjected to ultrasonic vibration were investigated using a newly developed tribology tester which can ultrasonically vibrate the specimen, and the mechanism and/or the best conditions for applying ultrasonic vibration to the dry processes and/or process performed with environment friendly oil were quantitatively examined. |
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EP-1-3 Evaluation Of Galling and Seizure Resistance of PAPVD TiAlBN and TiAlN Hard Coatings.
M.C. Joseph (The University of Hull, United Kingdom); A.D. Wilson, A. Leyland, A. Matthews (University of Hull, United Kingdom); J. Housden (Tecvac Ltd) The problem of galling with metallic materials used in certain high-load sliding contacts has been known for many years; this is especially true for stainless steel threaded fasteners. The application of alloying techniques and surface treatments to such steels can often reduce (but may not entirely eliminate) this problem. The aim of this investigation was to study the galling characteristics of austenitic stainless steel substrates coated with PAPVD TiAlBN and TiAlN. A Tecvac twin-electron-beam PVD coating rig was used to deposit TiAlBN and TiAlN ceramic coatings; all films were approximately 3µm thick. The treated surfaces were assessed using a modified VTT scratch tester, optical microscopy, SEM and surface profiling to evaluate the critical load at which galling occurs. XRD was used to characterise the near-surface region of the treated alloys. The corrosion resistance was also evaluated and surface hardness was determined by Knoop microhardness measurements. The improvements in galling resistance of PAPVD TiAlBN and TiAlN coatings are examined; comparisons are made with other surface modification techniques such as PAPVD hard coatings of TiN, CrN and PACVD-deposited DLC. |
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EP-1-4 Influence of Ce Plasma on Low Voltage Plasma Ion Implantation/Nitriding of AISI304 Stainless Steel
X.B. Tian, K.Y. Fu, L.P. Wang, P.K. Chu (City University of Hong Kong) *Elevated-temperature, low-pressure nitrogen plasma immersion ion implanatation (PIII) is very effective in enhancing the tribological properties of austenite stainless steel without degrading its corrosion resistance. In particular, low voltage PIII characterized by a thinner plasma sheath, higher incident ion flux and reduced high-voltage danger is more suitable for practical industrial applications. It has been shown that chemical heat treatments and other surface engineering processes are accelerated significantly by incorporating rare-earth elements into the processing medium, and there exists an optimal rare earth content. In this work, we focus on the effects of the addition of cerium on the nitriding efficiency of low-voltage PIII. A metal vacuum arc source is used to provide the rare earth element plasma with the proper flux by adjusting the pulsing frequency. The plasma diffusion behavior also makes it possible to treat components with an irregular geometry. In our experiments, we employ both hot filament glow discharge that produces a nitrogen plasma for nitriding of AISI304 samples and a filtered cathodic arc plasma source that generates the Ce plasma. During our experiments, the samples are heated to 350oC by the 2kV incident nitrogen ions. The pulsing frequency of the cathodic arc plasma source is adjusted between 10 Hz and 200 Hz to control the rare earth content. We will discuss the properties of the treated samples under various conditions. |
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EP-1-5 Abrasive Wear of TiN/Ti Multilayers Deposited by Sputtering with Variable Magnetic Field
M. Flores (LIM-UNAM, Mexico); M. Vite (Sepi-esime-zacatenco-ipn, Mexico); S. Muhl (LIM-UNAM, Mexico); E. Andrade (Instituto de Fisica-UNAM, Mexico) TiN/Ti multilayers, have been deposited by various PVD methods to improve the toughness, corrosion and wear resistance of coatings. In this work we report the results of preparing multiple TiN/Ti layers on H13 steel substrates by reactive magnetron sputtering with a magnetic field applied by a coil concentric to the balanced magnetron. We report the results of studies of the influence of magnetic field, period and multilayer constitution on the hardness and wear abrasion resistance of Ti/TiN multilayers. The wear was studied using a tribological tester developed in our laboratories. The tester uses dry sand/rubber wheel, according to the ASTM G-65 norm and was modified to apply low loads (20.3 N). It was found that magnetic field enhanced the hardness and wear resistance of multilayers. In multilayers with thick (500nm) individual thickness, a TiN top layer of 2 microns was seen to improve the wear resistance. The composition of the films was determined by ion beam techniques. |
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EP-1-6 Cavitation-Erosion of the Chromium Nitride on Steel by Cathodic Arc Plasma Deposition
S. Han (National Chung Hsing University, Taiwan, ROC); J.H. Lin (National Tsing Hua University, Taiwan, ROC); H.Y. Chen, J.J. Kuo (National Chung Hsing University, Taiwan, ROC); J.H. He (Feng Chia University, Taiwan, ROC); D.Y. Wang, F.-H. Lu (National Chung Hsing University, Taiwan, ROC); H.C. Shih (National Tsing Hua University, Taiwan, ROC) The cavitation-erosion behavior of CrN coatings on AISI 4140 steel in both D.I. water and 3.5% NaCl solution was investigated by an ultrasonic vibration system. Two types of CrN-coated steel by cathodic arc plasma were prepared either with or without an intermediate layer of the electroplated hard chrome, i.e. CrN/steel and CrN/Cr/steel. The composition and structure of the chromium nitride have been studied by X-ray diffraction (XRD), using both θ/2θ diffraction mode and Schulz reflection method. The microstructure and crystallinity of chromium nitride have been investigated using cross-sectional transmission electron microscopy (XTEM) and selected area diffraction (SAD). Both CrN/steel and CrN/Cr/steel assemblies exhibit a morphology of microcolumnar structures. For CrN/Cr/steel assembly, a preferred orientation of CrN(220) was observed. Cavitation-erosion tests were conducted under free corrosion, and therefore electrochemical evaluation was made to elucidate the role of cavitation-erosion. The resulting mechanical damage was studied using weight loss measurements and scanning electron microscopy observations. The results demonstrate that the CrN/Cr/steel exhibits a much longer lifetime before the onset of cavitation-erosion compared with CrN/steel. |
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EP-1-7 Adhesion and Tribological Properties of Diamond-Like Carbon Films Prepared by Pulsed DC Plasma-Enhanced Chemical Vapor Deposition
K Kawata (Oriental Engineering Co., Ltd., Japan); H. Sugimura, O. Takai (Nagoya University, Japan) Diamond-like carbon (DLC) films were prepared on Si and Steel substrares by pulsed dc plasma-enhanced chemical vapor deposition (PECVD) at 423 K. The pulsed dc PECVD apparatus consisted of a reaction chamber, an internal heater, a vacuum system, a rotation system for the working table, a pulsed dc power supply, a gas supply system and a computer-controlling system. The effective dimensions of the workpieces treated in this apparatus are 450 mm in diameter and 550 mm in height. In this investigation, steel substrates with and without pre-nitriding were used. The films were characterized by Raman spectroscopy and scanning electron microscopy (SEM). The hardness of the films was measured by nanoindentation method. The adhesion behavior of the films was studied by scratch tests and Rockwell tests. The tribological properties of the films were studied by ball-on-disk tests and Falex tests. Pre-nitriding of the steel substrate was effective to obtain good adhesion and tribological properties of the DLC films. |
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EP-1-8 Tribological Analysis of Nano-Composite Diamond-Like Carbon Films Deposited by Unbalanced Magnetron Sputtering
D.Y. Wang, Y.-Y. Chang (National Chung Hsing University, Taiwan, ROC) Diamond-like carbon (DLC) films posses superior mechanical, optical, thermal, and electrical properties for advanced eng ineering applications. However, the excessive residual stress of DLC induces fracture failure and severe interfacing difficult y to metallic substrates. To solve the brittleness problem, a nano-composite DLC film was deposited by using unbalanced magnet ron sputtering process. The composite microstructure consists of interlaced DLC films and metallic interlayers. DLC films wer e synthesized by sputtering of pyrolitic graphite targets. The enhanced ion current density of the unbalanced magnetron sputte ring process helps in formation of the superhard carbon coatings with amorphous mixture of sp3 and sp2 carbon bonds structure. Cathode currents and rotation speed of the planetary substrate holders control the thickness of each composite layer. Microst ructure of the composite DLC was examined by using transmission and scanning microscopy. The characteristics of diamond bonds was identified by using Raman spectroscopy. Tribological properties such as wear mechanism, transfer phenomenon, friction coefficient, and wear life were evaluated by using scratch and pin-on-disk tests as well as field analysis. |
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EP-1-9 Characterisation and Mechanical Properties of Ion Implanted Diamond Surfaces
H.-R. Stock (Stiftüng Institut fuer Werkstofftechnik, Germany); V. Schlett (Fraunhofer Institut Angewandte Materialforschung, Bremen, Germany) Single crystal diamond surfaces were treated by implantation of high energy nitrogen, chromium and titanium ions. Ion energies were chosen between 60 and 180 keV and ion doses up to 1x1017 ions/cm2. The samples were heated to temperatures of at least 750°C to prevent amorphisation of the diamond crystal. The near-surface zone was characterised by X-ray photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. To reduce the amount of lattice damage some of the samples were coated with a sacrificial layer, e.g. 100 nm titanium, which was removed after ion implantation by dissolution in nitric acid. Mechanical and reactive properties of the implanted surfaces against low-carbon steel were examined under grinding conditions in an UHV device under UHV conditions and defined oxygen partial pressures. It is shown that the wear of the implantation influenced zone of the diamond sample can be reduced significantly. Possible mechanisms of the enhanced wear resistance are discussed. |
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EP-1-10 Effect of Carbon Nanotube Infiltration on the Tribological Behavior of Carbon Fiber Composites
D.S. Lim, J.W. An (Korea University, South Korea) The uses of carbon composites are limited in some applications because their tribological properties are not always superior under various conditions. Nanotube composite coatings were applied onto the carbon composites to improve wear property since carbon nanotubes have shown excellent mechanical characteristics. Carbon nanotubes have been prepared by catalytic pyrolysis of hydrocarbons. The nanotube slurry was prepared by addition of phenolic resin and solvent to infiltrate into carbon composites. The nanotube infiltrated carbon composites were then carbonized in a nitrogen atmosphere. Ball-on-disc type wear tests were performed to evaluate the tribological properties of untreated and infiltration treated carbon composites. The result showed that nanotube infiltration technique has potential to increase the wear resistance of carbon composites. Changes in hardness, morphology and surface damage due to nanotube infiltration were studied to explain observed wear behavior. |
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EP-1-11 Microstructural Basis for Wear-Durability Changes Caused by Pt/Ti Alloy Formation Produced by Two Different Techniques*
T.J. Renk (Sandia National Laboratories); J.R. Treglio (Cutting Edge Products, Inc.); C. Suryanarayana (Colorado School of Mines) The near-surface region of metals can be modified by the addition of alloying metals through several different non-equilibrium processes. The resulting surface exhibits enhanced wear durability, both in tribological wear testing, and in real-world use. We have investigated the microstructure and wear durability of Pt-enriched Ti-2 produced by two different techniques: 1) high-dose ion implantation of the Pt into a Ti-2 substrate (1017 cm-2), and 2) a 1-micron Pt/Ti sputtered layer mixed into a Ti-2 substrate by a high-power ion beam. In the first case, the Pt has an estimated range of 20 nm, and in the second, the beam treatment results in a 2 micron layer of melted and mixed metastable alloy. After sample preparation, both types of samples were analyzed by cross-sectional TEM. In both cases, microstructural changes were observed that extended well beyond the ion range and heat-affected zone. In the high-dose implantation sample, a Pt-enriched layer was observed to form near the surface, and the effects of grain refinement extended to near 1 micron depth. In the Pt/Ti surface alloyed sample, 1-micron single crystal grains with Pt in solid solution were observed in the melt layer. Below the melt zone, enhanced dislocation tangles, twinning, and martensite formation formed up to 150 microns below the surface. We plan tribological wear tests on both samples, and will correlate wear performance to the microstructural features seen with the XTEM. We have previously1 reported significantly improved wear durability in samples of Ti-5 substrates in which Pt/Ti sputtered layers have been surface alloyed. |
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EP-1-12 Wear Behavior of a Silicon Carbide Enriched Composite Electroless Nickel at High Temperature
M.H. Staia, A. Conzono (Universidad Central de Venezuela); A. Roman, J. Lesage, D. Chicot, G. Mesmacque (UST Lille, IUT A, France) In the present paper we report the results obtained from sliding wear tests of as-deposited and heat treated silicon carbide enriched composite nickel coatings. The coatings have been deposited industrially on AISI 1020 steel discs by using a proprietary self-catalyzing chemical reduction process( HARDEX®). The tests were conducted without lubrication, at room temperature and at higher temperature (100-400°C), employing a tribometer under the pin on disc configuration. The mating pair were alumina balls of 6mm diameter. Surface topography of the wear scars has been analyzed by using Zygo NewView 200 profilometer. The wear scars on both discs and pins have been studied using SEM and X-Ray elemental mapping in order to determine the wear mechanism. |
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EP-1-13 Tungsten Laser Alloying of an A-356 Aluminum Alloy - Tribological Performance and Characterization
M.H. Staia, C. Sanchez (Universidad Central de Venezuela); N.B. Dahotre (The University of Tennessee Space Institute); A. Roman, J. Lesage, D. Chicot, G. Mesmacque (UST Lille, IUT A, France) In the present work, sand cast Al-356 alloy was laser alloyed with W using “two stage” technique of laser alloying. A continuous wave fiber optically delivered Nd-YAG laser was employed for alloying the W powder and the coatings were produced by varying beam interaction with the substrate as result of the variation of the traverse velocity of laser. Characterization of the laser treated alloy was performed by various techniques. Optical (OM) and Scanning Electron Microscopy (SEM) were used to examine the morphology and microstructure of the sample surfaces and cross sections. X-Ray diffraction was conducted to determine the nature of the various phases present at the surface. Friction and wear tests were carried out on all samples by using a ball-on-disc tribometer under dry conditions. The static partners were balls of 6 mm diameter made of AISI 1086 steel and WC+6%Co. Variation of friction coefficients with the sliding distance are also reported. The wear mechanism for each tribological pair was determined by using SEM and X-ray elemental mapping of the wear scar. It was found that the laser alloying process of the aluminum alloy has improved its wear resistance if it is compared with the behavior of the unalloyed substrate. |
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EP-1-14 Abrasion Resistance of Recycled Polymer Coatings
M.S.B.P. Santos, J.R.T. Branco, K.S. Al-Rubaie (Fundação Centro Tecnológico De Minas Gerais- Cetec, Brazil) The concern with the environment preservation has demanded increasing effort to recycle plastics. In a previous investigation we have reported the possibility to manufacture thermal sprayed coatings from recycled PET. Pin-on-disc data demonstrated that coatings had even better wear behavior than virgin PET. In the present work we have investigated the effects of PMMA content on the pin-on-disc and scratching behavior of PET-PMMA blends, in dry condition. AISI 52100 steel 6 mm balls, with and without TiN coatings were used as counterbody. The pin-on-disc wear testing were carried out under 1, 5 and 10 N load. The scratching was performed with 1, 5, 10, 50 and 100 N. Friction coefficient, acoustic emission, volume and mass loss were monitored during testing. The paper also investigates on the effect of counter body surface roughness and sliding speed. |
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EP-1-15 Influence of Ion Kinetic Energy on Crystalline Quality of Cerium Dioxide Thin Film Synthesized by Dual Plasma Deposition
L.P. Wang, B.Y. Tang, K.Y. Fu, X.B. Tian, P.K. Chu (City University of Hong Kong) Dual plasma deposition incorporating plasma immersion ion implantation (PIII) and plasma deposition is a novel and effective method for the fabrication of functional thin films. One of its advantages is the easily adjustable ion kinetic energy. By varying the applied voltage, we systematically investigate the effects of ion bombardment energy on cerium dioxide thin film fabrication by dual plasma deposition. We also study the effects of DC and AC bias on the crystalline quality of the film. The samples are characterized by x-ray diffraction and Rutherford backscattering spectrometry. It is found that the kinetic energy of the incident ions has a significant influence on the crystalline quality of the thin film. When the kinetic energy is proper, good crystalline quality can be achieved at a deposition temperature as low as 200C. |
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EP-1-16 Effects of Gas Pressure on Elevated-Temperature Plasma Immersion Ion Implantation Using Hot-Filament Glow-Discharge Plasma
X.B. Tian, X.C. Zeng, L.P. Wang, P.K. Chu (City University of Hong Kong) Elevated-temperature plasma immersion ion implantation (PIII) has been proven to be an effective surface modification technique for materials such as aluminum and stainless steel that is difficult to nitride. Using low pressure (0.1Pa~0.5Pa), RF or ECR plasma, and medium implantation energy (<50kV), a thicker nitride layer can be obtained. At a constant sample temperature, a low implantation voltage can lead to a high incident ion flux to expedite diffusion of implanted nitrogen, thereby improving the modification efficiency. In this case, a higher implantation voltage is not necessary. On the other hand, a higher voltage results in a higher retained dose when using a nitrogen plasma sustained by hot filament glow discharge at a gas pressure less than 0.1 Pa in our previous experiments. It is believed that the difference originates from the influence of the working gas on the experimental parameters such as sputtering rate, net ion incident energy, and excited particle density. In this work, the impact of the gas pressure on the elevated-temperature plasma immersion ion implantation process is investigated at a typical gas pressure range between 0.5 Pa and 0.02 Pa. |
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EP-1-17 Resistance to the Abrasive Wear of the Coating Obtained of Welding by the Technique Shield Welding Arc Deposited on Steel A-36.
M. Vite, M. Castillo, J. Aguilar, J.L. De la Luz, E. Gallardo, P. Villegas (Sepi-esime-zacatenco-ipn, México); J. Vite, F. Palacios (Inin, Centro Nuclear, Salazar, Edo. de México) In this work we report the resistance to the abrasive wear of the coatings of Stellite (alloys with cobalt, chromium, tunsgsten and molybdenum) and of Inconel 600 ( nickel alloys containing chromium, and a little manganese, silicon, and niobium) deposited on steel A-36. We used for mesauring wear abrasion a tribological tester developed in our laboratories. The tester uses a dry sand / rubber whell according to the ASTM G-65 norm. The coatings were obtained by the technique Shield Welding Arc, with a heating of the electrode of 70 °C, while the temperature of the environment was of 25 °C. We have been obtained layers of alloys mentioned. The first layer, has a thickness of 2 mm, the second layer of 4 mm and the third layer of 6 mm. We carry out a characterization of the coatings using the techniques of scanning electronic microscopy, X-ray diffraction, as well as the mensuration of the hardness and microhardness. |
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EP-1-18 Mating Surfaces Fatigue Life Extension Using Super finish and Hard Coating
A Manesh (IIT Research Institute); S Naik (Rolls-Royce) In the last few years, vacuum coatings have been used by auto industries for applications such as reduction in coefficient of friction, increased fatigue life, and increased load bearing capacity. As part of continuous improvement at Rolls-Royce, several technology programs for gas turbine engines lead to requirements for higher power density level to be transferred though power-train system. However, higher torque transfer through gearing systems can increase the potential of gear damage and loss in performance. This paper will discuss a joint effort by IIT Research Institute and Rolls-Royce that includes the selection of three candidate coatings for potential application in the aerospace industry. Each of the candidate coatings has been used in the tooling and auto industries to extending the durability of parts by a factor of 3. The coatings selected have low COF with high hardness values. All coatings selected are deposited by high vacuum technology whose benefits include controlled material composition and extreme precision, thereby eliminating the need for subsequent grinding. The performances of the coatings are evaluated in fatigue and life durability. Rolling / Sliding Contact Fatigue tests have been conducted on bare and coated SAE 9310 material. The contact fatigue tests have been performed at Gear Research Institute at Penn State. The durability investigation of the coatings has been conducted in a 4 - Square Gear Rig test system. The 4 - Square tests have been performed at NASA Glenn Laboratory at Cleveland OH. Both uncoated and coated SAE 9310 gears have been tested. The performances of the candidate coating systems are being ranked to select the optimum coating system. The supper finished surface prior to coatings have been evaluated by R/SCF test and the results are reported. This is a US Army Manufacturing Technology project and has been sponsored by the Aviation and Missiles Command (AMCOM) and managed by IIT Research Institute. |
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EP-1-19 FEA Modeling of Multilayer Films Under Hertzian Contacts
S.L. Rohde, L.G. Olson, S.M. S.M. Aouadi, T.Z. Gorishnyy (University of Nebraska - Lincoln) Finite Element Analysis (FEA) was used to model stresses within sputter depostied chromium nitride films in ordet to develop a coating design and optimization methodology to help researcher and development scientists in the selection of coating materials and architectures for use under specific loading conditions. First generation Cr-N coatings have been deposited via ion enhanced PVD techniques and their mechanical properties determined experimentally. Additionaly, their relative wear behavior assessed under controlled pin-on-disk testing to assisting developing optimization stratagies for second generation thin film growth experiments. The results of the FEA studies, PoD wear behavior, and optimization routines will be dicussed in in terms of thier impact on second generation coating development. |