ICMCTF2003 Session EP: Symposium E Poster Session

Thursday, May 1, 2003 5:00 PM in Room Town & Country

Thursday Afternoon

Time Period ThP Sessions | Topic E Sessions | Time Periods | Topics | ICMCTF2003 Schedule

EP-1 Plasma Immersion Ion Implantation of Industrial Gears
Z.M. Zeng, R.K.Y. Fu, X.B. Tian, P.K. Chu (City University of Hong Kong)
Plasma immersion ion implantation (PIII) circumvents the line-of-sight restriction imposed by conventional ion beam ion implantation (IBII), and has been shown to be an effective surface treatment technique for industrial components, especially those possessing an irregular shape. Gears are widely used for rotary motion in various industrial machines. Industrial gears, mostly made of steels processed under various heat treatment conditions or nitrided steels, require high surface hardness, good wear resistance and excellent fatigue properties. The working surface of a gear is its tooth surface, and so a gear has a complex shape. PIII is a good method to improve the surface properties of a gear. In this work, we focus on the PIII treatment of real spur gears. Argon and nitrogen PIII was conducted on the gear surface and the implant uniformity along the gear surface was investigated. Rutherford backscattering spectrometry (RBS) was used to determine the implanted ion dose along the gear surface using silicon pieces affixed at different positions. The results show that the lateral difference is quite large but the ion dose distribution along the gear surface for argon and nitrogen is almost the same. We have also found a large iron content on the silicon surface at some positions, which corresponds to the degree of sputtering near this position and also reflects the ion implantation angle and energy. In this paper, we will discuss the distribution of the sputtering angle along the gear surface, especially along the tooth surface and contaminants such as oxygen.
EP-2 Study of the Adhesion of Multilayered Coatings using the Scratch Testing Technique
E. Poiré (Micro Photonics, Inc.)
Measuring the mechanical properties of multilayered coatings is not an easy task especially when the point of interest is the adhesion between each of the layers. The nature and thickness of the materials in use as well as the strength of the interfaces contribute to the delamination process. This paper will present the use of micro and nano scratch testing as a tool to study the adhesion of coatings and multilayered coatings. Results show that by varying the testing parameters one can study the adhesion properties of each layer.
EP-3 The Effect of Post-annealing Treatments of Graphit-iCTM Coatings on their Friction and Wear Properties
D. Mercs, S. Taylor, D.G. Teer (Teer Coatings Ltd, United Kingdom)
Graphit-iCTC is a hard amorphous carbon coating (a-C) containing a small amount of chromium, which exhibits high load bearing capacity (80-100 N) under pin on disk tests and shows excellent friction and wear properties when rubbing against hard metallic or ceramic counterparts. However, it is common to observe a high friction coefficient (0.2 - 0.3) at the start of pin on disc tests which rapidly decreases to reach a very low steady state value (~ 0.06). This running in period can lead to wear of the sliding counterpart. Post-annealing treatments of Graphit-iCTC coatings have been performed in air for different temperatures and durations. Heat treatment of Graphit-iCTC at 300°C for 3 hours leads to significant improvement of the coatings tribological properties. No running in was observed during pin on disc tests performed at 80N and the friction coefficient and the specific wear rate of the coatings were respectively as low as 0.05 and 9.10-18 m2.N-1. Multi-pass tests with a normal load of 80 N were also performed and confirmed the improved properties of the coatings after heat treatment. Finally, the structural evolution of the coatings after post-annealing treatments was investigated using Raman spectroscopy.
EP-4 The Thermal Oxidation Effect on Corrosion Resistance of CrN Coated Steel by Cathodic Arc Deposition
K.L. Chang, S.-C. Chung, P.-Y. Lim, C-.C. Lin, S.-H. Lai, Han. C. Shih (National Tsing Hua University, Taiwan, ROC)
The CrN coatings were prepared by using cathodic arc deposition on AISI 304 stainless steel. Thermal oxidation of the coatings in air was carried out at temperature 500°C and 800°C. The composition and structure of CrN coatings were studied by grazing X-ray reflectivity (GIXR) and Auger electronic spectroscopy (AES). The corrosion resistance of samples was investigated by electrochemical impedance spectroscopy (EIS) and cyclic potentidynamic measurements in a mixture of acid and saline solutions. The Cr2N and Cr2O3 phases were observed after oxidation of CrN coatings. The corroded samples were also examined by scanning electron microscopy to perform a microstructural analysis. Those results indicate that the corrosion resistance of CrN coated steel is associated to different phases formation at elevated temperature.
EP-5 Comparison of a Simulated "In-service" Rig Test with a Standardised Laboratory Sample Abrasion Test
L. Whittaker (University of Hull, United Kingdom); A. Matthews (The University of Sheffield, United Kingdom)
Over the past few decades many laboratory wear tests have been developed to simulate a range of wear conditions, from two- and three-body abrasion to sliding friction and sold particle impingement. However it is often questioned how relevant and useful such laboratory tests are in evaluating the likely in-service performance of coatings and treatments intended to reduce wear and improve the lifetimes of real industrial components This paper presents a comparison of the wear scars generated from an "industrial" rig test, replicating the operation of pump components under actual operating conditions, with those from a laboratory abrasion test. The major variables involved in each of the test systems are also compared. The industrial rig system is the pumping element of a progressive cavity pump which consists of a metallic single helical scroll which rotates inside a double helical rubber stator. When the pump is used to transfer slurries the operational life of the two components is significantly reduced due to the presence of abrasive particles. The laboratory test selected to simulate this tribological system is the rubber wheel abrasion test using a wet slurry feed, as this system provides similar counterfaces and tribo-contact conditions to the real system. Laser profilometry and scanning electron microscopy were used to compare and contrast the wear scars generated from each system. The results demonstrate that the laboratory test has some validity within certain parts of the industrial system, but for a meaningful indication of likely wear life, full 'in-service' test conditions are needed.
EP-6 Evaluating the Fracture Properties and Fatigue Wear of ta-C Films on Silicon with Nano-impact Testing
B.D. Beake (Micro Materials Limited, United Kingdom); D.S.P. Lau (Nanyang Technological University, Singapore); J.F. Smith (Micro Materials Limited, United Kingdom)
A repetitive contact technique, nano-impact testing, has been used to investigate the fracture properties of tetra amorphous carbon thin films deposited on silicon by the filtered cathodic arc method. The impact test has shown clear differences in the resistance to impact wear of ta-C films with their thickness, for film thicknesses between 5 and 80 nm. The resistance to impact-induced fracture drops as the film thickness increases. This may be due to the maximum shear stress being closer to the film-substrate interface, or reflects reduced toughness in the thicker films which are less able to deform as the substrate deforms plastically during the repetitive contact test. The influence of impact load on fracture probability has been investigated. Fracture probability increases sharply as the impact load is increased from 100 to 300 micronewtons. The greater load provides the stresses necessary to nucleate and propagate the sub-surface cracks; at low load the driving force for the cracks to coalesce and spall the coating is much reduced, so failure is less likely to occur within the test duration. The impact damage process involves 3 stages (1) initial impact stage where plastic deformation causes cracks to begin to nucleate sub-surface (2) fatigue - further nucleation and growth of cracks sub-surface but no change in probe depth (3) crack coalescence and film fracture which leads to a rapid change in probe depth as the film fails.
EP-7 Development and Optimization of a Superlattice TiHfCrN Coating for Cold Metal Forming Applications
E. Lugscheider, K. Bobzin, C. Colmenares, F. Klocke, T. Massmann (Aachen University, Germany)
Tribosystems in mechanical engineering put high demands towards tools, surface technology and lubrication. Especially cold forming processes represent a great challenge for wear reduction. Mineral based oils with high contents of ecologically harmful additives are state of the art due to high abrasive and adhesive wear. In order to reduce the ecological impact and to increase tool life, biodegradable lubricants and hard coatings have been developed, which are deposited by modern vacuum technologies. In the collaborative research center "environmentally friendly tribological systems" (SFB 442) which has been established by the German Science Foundation (DFG), a new Arc-PVD Ti-Hf-Cr-N coating has been developed. This nanolayer system with single layers of different hardnesses is supposed to fulfill the requirements of high hardness and abrasive wear resistance while possessing low Young's modulus values at the same time. In this paper, the results of coating characterization based on various standardized tests and on microscopic analysis are shown. The influence of the nanolayered structure and the coating process on the performance is evaluated using nano-indentation and pin-on-disc tests. In addition, cup-backward-extrusion and fine blanking tests were made in order to examine the coating behavior in real cold forming processes.
EP-8 Tribological Properties of Chlorine-ion implanted Zirconium Nitride Film
A. Mitsuo (Tokyo Metropolitan Industrial Technology Research Institute, Japan); T. Aizawa (University of Tokyo, Japan)
Zirconium nitride films were prepared by ion-beam assisted deposition (IBAD) on single-crystal silicon substrates. The films were synthesized by depositing the zirconium vapor from an electron-beam source, under the irradiation of nitrogen ions from an arc ion source. Transport ratio of Zr to N was varied from 1.0 to 3.0 by controlling deposition rate of Zr. The nitrogen ion beam density was kept constant, 0.2 mA/cm2. The ion beam energy was varied between 0.5 and 2.0 keV. Post chlorine-ion implantation was performed at doses of 0.5 and 1.0 x 1017 ions/cm2 for a constant energy of 100 keV. The films were characterized by X-ray diffraction for crystal structure and Auger electron spectroscopy for the distribution of the constituent elements. Hardness of the films was measured by a nano-indentation tester. The films were tested for friction and wear on a ball-and-disk tribometer, under the normal load of 5 N and the relative sliding speed of 10 mm/s. The stainless steel balls were used as a counter material. Formation of ZrN in film was recognized in X-ray diffraction pattern for all deposition conditions. Depth profiles measured by Auger electron spectroscopy showed that the composition ratio of Zr to N was uniform in the inside of film, and the implanted Cl atoms distributed in a Gaussian-like profile near the surface of the film. The hardness of the films increased with decreasing the transport ratio. Friction coefficient was significantly reduced from 0.8 to 0.25 at the initial stage of testing by the chlorine-ion implantation. Tribological properties will be discussed and compared with the chlorine-ion implanted TiN films.
EP-9 A Wet Chemical Etching Process to Remove TiN Coatings from WC-Co Substrates
M. Becker (Fraunhofer USA); E. Flint (Bradley University); T. Schuelke (Fraunhofer USA)
Several potential decoating techniques have been investigated to strip ceramic films from WC-Co substrates, such as vacuum etching, atmospheric etching and wet chemical etching. A wet chemical etching process for decoating TiN from WC-Co has been developed and compared to existing commercial processes, such as high temperature etching, ion beam etching and wet chemical etching. The development included investigations of various oxidizing agents, chelating agents and alcohols, and solution parameters such as pH, concentration and temperature. A process capable of etching the coating within 4.5 hours was developed. The etching solution consists of isopropyl alcohol as the solvent and hydrogen peroxide as the oxidizing agent. The solution is adjusted to a pH of 10 -12 and kept at a temperature of 40°C. The comparison with existing industrial decoating processes shows that a new competitive decoating process has been developed.
EP-10 Effect of Aluminum Concentration on Friction and Wear Properties of Titanium Aluminum Nitride Films
H. Ohnuma (Shibaura Institute of Technology, Japan); N. Nihira, A. Mitsuo (Tokyo Metropolitan Industrial Technology Research Institute, Japan); K. Toyoda (Shibaura Institute of Technology, Japan)
It is well-known that the hard thin ceramic films were utilized to industrial applications such as cutting tools, molding dies and sliding parts, because of its effect of reducing the wear. Recently, demand of TiAlN film is expanding, because TiAlN film has high oxidation resistance at high temperature as well as wear resistance. In the present paper, friction and wear properties of TiAlN films having various concentration ratios of Ti/Al have been studied. The films were deposited by a cahodic arc ion plating method on WC-Co substrates in thickness of approximately 3 µm. Composition of the deposited films was evaluated by an energy dispersive X-ray spectroscopy (EDX). The crystal structure of the deposited films were characterized by X-ray diffraction (XRD). The hardness of films was measured by a knoop hardness tester and a nano-indentation tester. Friction and wear tests were carried out by a pin-on-disk tribometer at various tempertature. Composition of films deposited from cathode materials that have an atomic ratio (Ti:Al) of 50:50, 34:66, and 25:75 in TiAl alloys were Ti0.6Al0.4N, Ti0.42Al0.58N, and Ti0.3Al0.7N, respectively. Ti0.6Al0.4N film was found to have a cubic structure and a strong (200) preferred orientation. Diffraction peaks for Ti0.42Al0.58N and Ti0.3Al0.7N films were quite different from that of Ti0.6Al0.4N film. These phases were considered to be existent of AlN in a wurtzite structure. Knoop hardness and nano-hardness were decreased with increasing the aluminum contents in films. Friction and wear properties at high temperature will be discussed.
EP-11 Friction and Wear Properties of CrAlN and CrVN Films Deposited by Cathodic Arc Ion Plating Method
M. Uchida (Shibaura Institute of Technology, Japan); N. Nihira, A. Mitsuo (Tokyo Metropolitan Industrial Technology Research Institute, Japan); K. Toyoda (Shibaura Institute of Technology, Japan)
Chromium nitride film is superior to the titanium nitride film in corrosion, wear resistance and friction behavior. CrN has been widely applied to the molding dies, machine part and sliding part. In the present paper addition of Aluminum and Vanadium into CrN films are expected to improve oxidation and heat resistance. CrN, CrAlN and CrVN were deposited by an cathodic arc ion prating. Friction and wear tests were carried out by a ball-on-disk tribometer with stainless steel and WC-Co balls as a counter material, with and without lubricant. Deposited films were characterized by X-ray diffraction (XRD) for crystal structure identification and energy dispersive X-ray spectroscopy (EDX) for chemical composition analysis. Diffraction peaks appeared at the same position on the profiles in any films because the crystal structure and the lattice constant for CrN, VN and AlN are close to each ather. The component of the film deposited with Al and V were Cr70Al30N and Cr50V50N, respectively. Nano-indentation test showed that CrAlN was harder than CrN and CrVN. Delamination occurred on CrN with stainless steel ball in wear test without lubrication by ball-on-disk tribometer, but that did not occur on CrAlN and CrVN film. In the case of the wear test with WC-Co ball, depth of wear track for CrN film reached to the substrate. Al and V addition into CrN films improved their tribological properties.
EP-12 On the Effect of EMAA on the Tribological Behavior of Thermal Sprayed PET-EMAA Blends
G Custádio, D.S. Magalháes, J.R.T. Branco (Fund. Centro Tecnológico de Minas Gerais (CETEC ), Brazil)
The increasing consumption of PET - Poly(Ethylene Therephthalate) demands investment to increase its recycling. Therefore a new recycling route is being pursued, which consists of powder manufacturing and thermal spraying. This paper investigates the tribological behavior of thermal sprayed PET-EMAA blends coatings processed from PET powder manufactured from post-consumer bottles. EMAA was used in three level: 5, 10 and 15% content in weight. The coatings have friction coefficient in the 0,10 through 0,25 range and this property was not significantly affected by the EMAA content. Thermal spraying promoted a significant increase in the wear resistance of the PET. These results are interpreted based on scratching behavior, hardness and elastic modulus properties, as measured by indentation testing. The structure of the blends was evaluated by X-ray diffraction, Infra-red spectroscopy and Differential Scanning Calorimetry.
EP-13 Study on Semidry/Dry Wire Drawing Using DLC Coated Dies
M. Murakawa, M. Jin, M. Hayashi (Nippon Institute of Technology, Japan)
Currently, in the field of industrial drawing, considering the viewpoints of decreasing the load on the environment, improvement of labor sanitation and cost reduction, the reduction of the use of lubricant, changing to an environmentally friendly lubricant and the reduction of the cost of cleaning smeared products and the disposal of used lubricant are strongly demanded. In this study, as a means of realizing the above-mentioned semidry or dry wire drawing process, we investigated the drawing process using DLC-coated dies. Namely, we experimentally demonstrated the semidry wire drawing with both a croline-free lubricant and a wash-free lubricant with the three kinds of drawing process, traverse direction ultrasonic-vibration drawing using DLC-coated bisected dies, cassette-roller dies drawing with DLC-coated rollers and conventional drawing using a DLC-coated hole die. As a result of the experiments, we clarified that the traverse direction ultrasonic-vibration drawing method using DLC-coated bisected dies and the cassette-roller dies drawing process with a DLC-coated roller are effective in realizing semidry and dry drawing for stainless and aluminum wire.
EP-14 Localized Corrosion Mechanism of the Multilayered Coatings Related to Growth Defects
S.-H. Ahn, J.-H. Yoo, J.-H. Lee, Y.-S. Choi, H.-Y. Lee, J.-G. Kim (Center for Advanced Plasma Surface Technology (CAPST), South Korea); J.-G. Han (Center for Advanced Plasma Surface Technology ( CAPST), South Korea)
There are a number of trials for hard coatings to improve both the mechanical properties and the corrosion resistance in surface modification engineering where the properties of the single-layer are not sufficient. Multilayered WC-Ti1-xAlxN coatings were deposited on AISI D2 steel by cathodic arc deposition (CAD) method. These coatings contain structural defects such as pores or droplets. The growth defects (pore, porosity) are detrimental to coatings used in severe corrosion applications. It is important to understand the corrosion mechanism of coatings, which is helpful to design the corrosion-resistant coatings. The corrosion behavior of WC-Ti1-xAlxN coatings was investigated by electrochemical techniques in deaerated 3.5% NaCl electrolyte (galvanic corrosion test, electrochemical impedance spectroscopy and Mott-Schottky method) and surface analyses (XRD, AES, TEM, SEM and XPS). The pit morphology depends on the coating structure. The multilayered coatings exhibited a stretched laterally form after immersion test. This means that the multilayered coatings contribute to an increased resistance to pit propagation. Generally, localized corrosion behavior in the multilayered coating could be explained by three aspects : the corrosion products underneath the coating, the hydrogen evolution and the aggressive anion adsorption.
EP-15 Impact-wear Behaviors of TiN and TiAlN Coatings on AISI D2 Steel and WC-Co Substrates
K.H. Kim, S.-Y. Yoon, S.-Y. Yoon (Pusan National University, South Korea)
TiN and TiAlN coating layers were deposited onto AISI D2 steel and WC-Co substrates by arc ion plating technique to investigate the effect of substrate on fracture behavior during dynamic loading. Those layers were fairly adherent to AISI D2 steel and WC-Co substrate, and showed hardness values of 2300±100 kgf/mm2 and 3200±100 kgf/mm2 with a load of 25g, respectively. In the case of AISI D2 steel substrate, TiAlN coating layer showed much superior impact wear resistance to TiN layer during dynamic loading until 5x103 cycle. It could be suggested that the TiN coating layer was failed relatively by plastic deformation during impact test, while TiAlN coatings was failed by brittle fracture by impact energy. However, in the case of WC-Co substrate, TiN and TiAlN coating layers showed similar impact wear resistance above 103 impact cycle whereas TiAlN coating layer had a little higher resistant to dynamic loading as low as 103 impact cycle compared to TiN coating layer. It suggested that the effect of substrate is more dominant at higher impact cycle regardless of coating layers. In addition, the degrees of plastic deformation (Hardness/Elastic modulus) for coating layers on different substrates were estimated with nanoindentation technique. The larger plastic deformation was occurred in TiN coating layer on AISI D2 steel substrate, while TiAlN coating layer on WC-Co substrate showed smaller plastic deformation.
EP-16 Superhard Coatings for Industrial Application in Dry Operations
H.Y. Lee, J.G. Han (SungKyunKwan University, South Korea); S.H. Baeg, S.H. Yang (Korea Institute of Industrial Technology, South Korea)

In recent years environmental pollution and disposal problems have led to changes in the environmental consciousness of society. Increasing costs of raw materials and restrictions by law emphasize the need for changing products and manufacturing processes. In order to reach ecological manufacturing, a minimization of the whole environmental pollution as a result of manufacturing processes is necessary. Especially in machining fields, it is determined that cooling lubricant has been exhausted at twelve - million tons per year into the environment, which have caused serious environmental problem. For the solution of these problems, PVD hard coatings such as TiN, TiAlN and CrN have been successfully adapted to round cemented carbide tools and metal - cutting inserts for applications involving interrupted cuts and those requiring sharp edges due to good wear resistance and thermal stability. These general hard coatings, however, have been limited to the cutting process with high speed and lubrication free machining owing to the decrease of hardness and oxidation resistance in an elevated temperature. Therefore, superhard nanocomposite coating with high hardness and good thermal stability has been emerging as a very efficient film for the application for high speed machining tools.

In this study, WC - Co based superhard coatings were deposited on various machining tools ( endmill, PCB drill, inserts etc ) by cathodic arc ion plating process for life time improvement. In our preliminary result, the lifetime of the PCB drill was improved by more than two times than that of the ordinary one. This detailed study will be presented.

EP-17 Study of the Sliding Wear Behavior at High Temperature of the PVD MoZrAlSiN Coatings Deposited on AISI 1045 Steel
M.H. Staia, M. D'Alessandria, M.R. Cruz (Central University of Venezuela)
The present study is focused on the microstructure,mechanical properties and the wear resistance at high temperature of the system MoZrAlSiN coating/AISI1045 substrate.The coatings were deposited industrially by using the closed field unbalanced magnetron sputtering ion plating deposition technique.After deposition the coatings were characterized by means of the scanning electron microscopy technique coupled with energy dispersive X-ray analysis and their structure was determined by X-ray diffraction.Scratch test method was employed to determine the coating adhesion.The hardness of the coating was determined by using nanoindentation tests.Wear tests were conducted using a ball-on-disc tribometer to evaluate the tribological behavior of the coatings.The tests were carried out without lubrication.The effect of temperature was investigated for the uncoated discs at two temperatures of 25° and 300°C,respectively using 6mm sapphire ball, a normal load of 5N and with a sliding velocity of 0.1 m.s-1.The wear behavior was determined by applying similar experimental conditions to the coated discs at temperatures of 25°C,300°C and 500°C,respectively. It was determined that the values of the friction coefficient increased with temperature achieving average values as high as 0.9 to 1. Despite the severe conditions of the wear tests and the high average values of the friction coefficients achieved during them,all tested coatings remained adhered to the substrate.It was determined that the coating deposition has a beneficial effect on the wear performance of the AISI 1045 steel at any tested temperature, contributing to a substantial decrease in the value of the worn volume.For example,at 25°C the wear volume of the coated system was nearly 30 times smaller than the wear volume corresponding to the uncoated steel.The wear mechanisms were discussed and were related to the changes in the friction coefficients values and the corresponding topographical analysis of the worn surface.
EP-18 Analysis of Cracks Initiation and Propagation in Surface and Subsurface of the Brittle Material During Microscratch Test
A. Djamai, K.J. Chin, D.H. Zaidi (Universite de Poitiers, France)
We have characterized the surface cracking of brittle material (glass) by microscratch tester ST3001, equipped with acoustic emission detector. The transparency of glass permits us to visualize directly the cracks on surface and their propagation direction in subsurface. The microscratch test was made by Rockwell C indenter with a radius of 0.8 mm, under progressive applied normal load (5N ~ 200N) at low sliding speed. The tangential friction force and the acoustic emission during scratch testing were recorded according to the time and the load. In addition to these tests, a model by numerical method in three dimensional analysis of stress field was developed to solve the fracture mechanics equation related to failure initiation and propagation of the cone cracks. In this paper, we will present the experimental study of microscratch test on a fragile material, glass. We will determine the critical load obtained by microscopic optical measurement to observe the contact surface and the subsurface. From the modeling of contact stress field, we will correlate the critical normal load to the cone cracks size with different friction coefficient values.
EP-20 Microstructure and Tribological Performance of Magnetron Sputtered WC/C Coatings
N.J.M. Carvalho (University of Groningen, The Netherlands); B.J. Kooi (University of Groningen and Netherlands Institute for Metals Research, The Netherlands); J.Th.M. De Hosson (University of Groningen, The Netherlands)
Tungsten carbide/carbon (WC/C) coatings with a superlattice structure deposited by PVD have been the focus of an extensive study because of their low friction coefficient and high wear resistance. Their deposition onto machine components that are subjected to a high shear stress component has been boosted by the deposition of an interlayer of chromium, improving the adhesion between the coating and the substrate. However, it is still necessary to gain a better understanding of the relationship between the chemical composition, the microstructure, and the tribological performance to tailor materials for specific applications. Friction and rolling contact fatigue testing have been performed to determine the friction coefficients, to characterize the mechanism of interfacial failure and consequently the coating adhesion. In this paper the crucial role of analytical and high-resolution transmission electron microscopy is emphasized in the analysis of the reactions that occur between the contact surfaces, of the transfer material between the surfaces, and the subsurface deformations.
Time Period ThP Sessions | Topic E Sessions | Time Periods | Topics | ICMCTF2003 Schedule