ICMCTF2005 Session EP: Symposium E Poster Session

Thursday, May 5, 2005 5:00 PM in Room Town & Country
Thursday Afternoon

Time Period ThP Sessions | Topic E Sessions | Time Periods | Topics | ICMCTF2005 Schedule

EP-1 Friction Properties of Co-sputtered Sulfide/DLC Solid Lubricating Films
J. Noshiro, S. Watanabe, T. Sakurai, S.M. Miyake (Nippon Institute of Technology, Japan)
DLC films having excellent properties are being applied in various fields as tribo-materials. However, depending on application environments, the friction properties of the DLC films are not enough to meet the demands in such fields. We fabricated MoS2/DLC and WS2/DLC nano-composite films having dry lubricating characteristics by multi-cathode RF magnetron sputter system using graphite, molybdenum sulfide (MoS2) and tungsten sulfide (WS2) targets. By adding the nano-cluster of MoS2 or WS2 into DLC matrix using co-sputtering, therefore, tribological properties of the DLC films are significantly improved. Friction and wear properties of the films were examined by the ball-on-disk friction test technique. Moreover, the elemental composition of the films have been analyzed using AES. In this study, the results show that the tribological properties of the sulfide/DLC nano-composite films have been significantly improved compared with those of the DLC film.
EP-3 Tribological Properties of DLC Film on a Silicon Substrate with and without Metal Interlayers
Y.S. Jeon, W.S. Choi, B. Hong, C.W. Cho, Y.Z. Lee (Sungkyunkwan University, South Korea)
We investigated the tribological properties of DLC films with metal interlayered between Si substrate and thin film. DC magnetron sputtering method was used to prepare metal interlayers. And RF-PECVD method was employed to synthesize DLC onto substrates of the silicon and metal layers. The three different metals were used for inter-layers on Si substrate and they were chromium (Cr), nickel(Ni), titanium (Ti). In this study, it was made a comparative analysis for tribological properties of DLC (30 nm) and DLC (20 nm)/metal (10 nm) films. The thickness of each layer was observed using cross section of thin film with field emission scanning electron microscope (FE-SEM). Also the surface morphology of the film was observed by an atomic force microscope (AFM). The tribological performances of the films were observed by both of AFM in friction force microscope mode, nano-indenter and pin-on-disk (POD) measurement. From our several measurements, Cr is suitable interlayer material to improve tribological properties of the very thin DLC films.
EP-4 Deposition of Ternary B-C-N Thin Films by Means of Ion-Plating
S. Watanabe, S.M. Miyake, T. Ezura, M. Murakawa (Nippon Institute of Technology, Japan)
Ternary boron-carbon nitride films have been deposited by several kinds of vapor phase techniques including plasma-CVD, ion beam deposition, laser ablation and sputtering techniques, because of considerable interest as promising technical materials with many favorable properties for mechanical, optical and electronic applications. The BCN ternary system containing the superhard materials, DLC and c-BN exhibits an extraordinary combination of extreme mechanical and physical properties due to their bonding characteristics and crystal structure. Therefore, it is expected the films will be very useful for tribological coatings on various industrial substrates. The magnetically enhanced plasma ion plating method, which has been successfully to form c-BN films, was used as the film formation method. Ternary B-C-N films were deposited on Si substrate by reactive evaporation in boron vapor using an electron beam and highly ionized gas was supplied adjacent to the substrate. Ar-N2-CH4 mixed gas was flowed into the chamber. The tribological properties of films deposited under various conditions were investigated. These properties were compared to find the effect of gas flow ratio and resultant compositional changes on this ternary system. Chemical bonding states, composition and structure of the films were performed by FT-IR and AES analysis.
EP-5 High Speed Wear Behaviors of CrSiN Coatings for the Industrial Applications of Water Hydraulics
S.D. Kim (HanKuk Aviation University, South Korea); S.Y. Lee, G.S. Kim (HanKuk Aviation Unversity, South Korea); Y.S. Hong (HanKuk Aviation University, South Korea)
In this study, studies were made to investigate the high speed weat behaviours of CrSiN coatings for the applications of environmentally friendly hydraulic components which utilize tap water as a transmitting media. Several PVD coatings were deposited on hydraulic components and their chemical and mechanical properties were investigated by AES, SEM, XRD, nanoindentation test and scratch test. The tribologocal properties were also evaluated by high speed wear test. The hardness of Cr-Si-N coatings gradually increased with increasing Si content and reached the maximum value of approximately 24 GPa at the Si content 9.8 at. %, this value is approximately 1.6 times higher than that of the CrN. Much improved friction behavior under tap water environment without delamination or surface cracking up to 1600 rpm by applying Cr-Si-N coating on the AISI 4340 cylinder barrel was observed. Even an initial decrease in the friction coefficient at the starting and low rpm region was resulted and this improvement was accompanied by friction mode change from adhesive mode to abrasive mode. Detailed experimental results including description of high speed tester used in this work will be illuminated.
EP-6 Tribological Performance of Chromium / Chromium Carbide Multilayers Deposited by r.f. Magnetron Sputtering
M.A. Gómez Botero, J. Romero, A. Lousa, J. Esteve (Universitat de Barcelona, Spain)
Hard ceramic and ductile metal materials combined in multilayered structures are well-known to produce coatings with improved mechanical and tribological behaviors. We have previously reported mechanical and structural results on nanometric chromium/chromium carbide (Cr/CrC) multilayers deposited by r.f. magnetron sputtering showing high hardness and with promising tribological applications. Therefore, in this paper we report the tribological properties and behavior of these Cr/CrC multilayers. Adhesion, sliding and abrasive wear tests were performed on Cr/CrC multilayers onto steel substrates, as well as on Cr and CrC reference coatings. The Cr initial layer played an important role in the adhesion onto steel substrates and was necessary when depositing CrC reference coatings. The sliding wear behaviour of Cr/CrC multilayers was investigated using ball-on-disk technique with alumina and steel counterparts while the abrasive wear was tested against diamond powder wheel. The abrasive wear resistance was directly correlated to the hardness of the multilayers. The multilayered coatings exhibited a sliding wear resistance three times improved as compared to CrC reference one. The Cr/CrC multilayers showed a dry friction coefficient around 0.2 during sliding tests. The wear tracks, debris and transfer layers resultant in ball-on-disk tests were analyzed by energy dispersion spectroscopy (EDS). The main mechanisms in sliding wear were identified as abrasion and tribochemical wear for alumina and steel balls respectively.
EP-7 Tribology of Nanostructured Protective Coatings for Jet Engine Blades
D.L. Schulz, A Shankaran, G.J. McCarthy (North Dakota State University); R.C. Tucker (The Tucker Group, LLC); M. Ray, G.E. McGuire (International Technology Center); P. Sunal, M.W. Horn, R. Messier (Pennsylvania State University)
A gas jet erosion facility has been established at the Center for Nanoscale Science and Engineering (CNSE) at North Dakota State University to characterize nanostructured protective coatings being developed by our partners, Pennsylvania State University (Penn State) and International Technology Center (ITC). This system (designed by Bud Labs) is comprised of three major components: a tungsten carbide micro abrasive blasting nozzle with an inner diameter of 1.5 mm and length of 50 mm; a sample holder capable of varying the angle between the nozzle and specimen from 15 to 90 degrees while maintaining a stand off distance of 10 mm; and, a used Jet Kote powder feeder system. A double disc velocimeter is used to calibrate the erodent stream velocity prior to each characterization cycle with TiN-coated M-2 steel used as the reference coating. In addition to documenting the system, this paper will present erosion resistance data for samples of nanostructured protective coatings on polished Ti6Al4V prepared at Penn State and ITC.
EP-8 A Study on the Effects of the Coating Properties on the Corrosion Behavior in Multilayered WC-Cr1-xAlxN Coatings on AISI D2 Steel
W.J. Kim (Sungkyunkwan University, South Korea); S.H. Ahn (Hyundai Motors, South Korea); J.G. Kim (Sungkyunkwan University, South Korea)
WC-Cr1-xAlxN coatings of stepwise changing Al concentration were deposited on AISI D2 steel by high-ionization sputtered PVD method. The Al concentration could be controlled by using evaporation source for Al and fixing the evaporation rate of the metals (WC alloy and Cr). The corrosion behavior of WC-Cr1-xAlxN coatings in deaerated 3.5% NaCl solution was investigated by electrochemical corrosion tests and surface analyses. Particular attention was paid to the effects of the coating properties on the corrosion behavior in multilayered WC-Cr1-xAlxN coatings. The measured galvanic corrosion currents between coating and substrate indicated that the C3 (WC-Cr0.32Al0.68N) coating showed the highest resistance of the coatings tested. The results of potentiodynamic polarization tests showed that this coating had lower corrosion current density and porosity. This indicated that this coating is effective in improving corrosion resistance. In EIS, the C3 coating showed the increased polarization resistance of coating compared to other coatings.
EP-9 LARC Tribological Coatings for Green Machining
M. Morstein, O. Coddet (Platit AG, Switzerland); M. Ruzicka (Pivot a.s., Czech Republic); O.T. Zindulka (SHM, s.r.o., Czech Republic)

One of the ongoing struggles in green metal machining operations is the control of friction and adhesion in the absence of boundary lubricants, especially if the tool works in difficult to cut materials. Tribological investigations provide a good opportunity for the selection of coating candidates suitable for critical conditions in applications such as tapping and forming.

The Platit LARCR technology provides a flexible means of adjusting the surface region of high-performance coatings according to the application demands. The range of available topcoatings comprises various sorts of low-friction layers, based both on carbon and on intrinsically low-friction nitride-based layers.

A further emphasis will be on the frictional characteristics of the new nACRoR AlxCr1-xN/Si3N4 nanocomposite, as well as related Zr-based coatings, as a function of their composition. Pin-on-disc tests in dry atmosphere are used to explore the frictional characteristics of these materials against different technically important alloy pins, including nickel-base alloys. The results are related to the coating characteristics.
EP-10 Mechanical Characteristics and Performance Evaluation by Cutting Edge Honing of Superhard TiN and Ti-Al-N Coating Tool
J.H. Park, M.C. Kang, J.S. Kim, J.-T. Ok, K.W. Kim (Pusan National University, South Korea)
TiAlN coatings have been known to be superior to other coatings such as TiN and TiCN in protecting tools which may be damaged by high thermal load. Up to now, many coating layers have been researched. But, no discussion has been study on the adhesion behavior between coating layer and substrate by cutting edge honing which is grinding on the tool surface sleekly. In this paper, we investigated a characteristic of honing effect. Prior to deposition coating layer, surface of cutting edge were fined by honing machine(SMAP2, TOYO) and optimal conditions were then investigated. TiN and TiAlN coatings were applied to end-mill tools made of WC-Co material by an arc ion plating(AIP) technique. These coatings were then characterized using XRD, optical microscope, AFM, micro-hardness and scratch tester. Their cutting performances in various cutting condition were evaluated.
EP-13 Fatigue Behavior of a 7075-T6 Aluminum Alloy Coated with an Electroless Ni-P Deposit
E.S. Puchi-Cabrera, C.J. Villalobos-Gutierrez (Universidad Central de Venezuela); I. Irausquin (Universidad Simon Bolivar, Venezuela); J. La Barbera-Sosa (Universidad Central de Venezuela); G. Mesmacque (University of Lille, France)
The fatigue behavior of a 7075-T6 aluminum alloy, coated with an electroless Ni-P (EN) deposit has been investigated by testing the uncoated and coated samples under rotating bending conditions in a wide range of alternating stresses, both in air and in a NaCl solution. The coating had a high phosphorous content, above 12 wt% and a mean thickness of approximately 37 microns. The static mechanical properties of the coated and uncoated material were also evaluated by means of tensile testing prior to the fatigue experiments. The results of such tests indicated that fatigue testing in air should be conducted in the range of alternating stresses of 269-430 MPa, whereas corrosion-fatigue tests were carried out at stresses in the range of 219-377 MPa. It has been determined that the presence of the EN deposit gives rise to an increase in the fatigue life of the alloy when tested in air, which can achieve up to 105% at alternating stresses of 269 MPa, whereas at 430 MPa the behavior of the coated alloy is similar to that shown by the uncoated material. On the contrary, under corrosion-fatigue conditions the life of the samples was observed to increase between approximately 55-71% when the samples were tested at the stresses indicated above. The SEM analysis conducted on the fracture surfaces and on sections normal to the fractures surface of some selected samples indicated that the fatigue failures were mainly due to the propagation of a single crack and that most of such cracks were associated with the presence of large nodules produced during the deposition process.
EP-14 The Nano Scratch Tester as a Tool to Measure the Coefficient of Friction
E. Poiré (Micro Photonics, Inc.)
The Nano Scratch Tester (NST) is commonly used to evaluate the scratch resistance of materials and the adhesion of coatings. However, its capability to measure extremely low load in small area makes it an attractive tool to measure the coefficient of friction. It can apply forces as low as 10 microN and scan lengths as small as 10 microns. This paper will present results of coefficient of friction obtained with the NST on high surface area materials and nanotubes as well as on selected metals.
EP-15 Wear Mechanism of Ni-P-BN(h) Composite Autocatalytic Coatings
O.A. León (Polytechnic Experimental National University (UNEXPO), Puerto Ordaz, Venezuela); M.H. Staia (Central University of Venezuela); H.E. Hintermann (Neuchatel University, Switzerland)
Wear experiments, using pin-on-disc configuration, have been employed in testing at room temperature autocatalytic composite Ni-P-BN(h) coatings against AISI 52100 steel balls. Coatings with 11, 35, 45 and 67 vol.% BN(h) were obtained by dispersing the BN(h) of an average particle size of 5.16 µm in a sodium hipophosphite based autocatalytic bath with enhanced agitation and surfactant addition. Scanning Electron Microscopy and 3D perfilometry techniques were employed to study the wear scars and to elucidate the wear mechanism of these composite coatings. Knoop microhardness, roughness, friction coefficients and wear resistance of the coatings for all experimental conditions are also reported.
EP-16 Wear-Corrosion Performance of Plasma-Sprayed Cast Iron Coatings on Aluminum Alloy for Automotive Components
W.J. Kim (Sungkyunkwan University, South Korea); S.H. Ahn (Hyundai Motors, South Korea); J.G. Kim (Sungkyunkwan University, South Korea); I. Ozdemir (Dokuz Eylul University, Japan); Y. Tsunekawa (Toyota Technological Institute, Japan)
The corrosion behaviors of coatings sprayed with water-atomized cast iron powder were investigated by electrochemical methods, such as potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) in deaerated 0.5M H2SO4 solution, and surface analyses. Water-atomized cast iron powders of Fe-3.75C-3.60Si-3.93Al (wt %) were deposited onto an aluminum alloy (AA383 alloy) substrate by atmospheric DC plasma spraying. Four types of samples were prepared including cast iron liner and aluminum alloy substrate. C1 coating was produced by using as-received water-atomized cast iron powders without graphite. C2 coating was deposited by using pre-annealing cast iron powder containing graphite structure. A synergism in wear and corrosion of cast iron coatings was investigated by tribological and electrochemical techniques. The results of electrochemical tests indicated that C2 coating had the increased corrosion-resistant property. This better corrosion performance could be attributed to the lower porosity, the higher protective efficiency and packing factor. This study provides the reliable and quantitative data for assessment of the effect of graphite structure on synergistic effect between wear and corrosion in the simulated body fluid environment.
EP-17 Optimization of Plasma Nitriding Process for Duplex Treatment
E.Y. Kim (HanKuk Aviation University, South Korea); G.S. Kim, S.Y. Lee (HanKuk Aviation Unversity, South Korea); S.D. Kim (HanKuk Aviation University, South Korea)
The duplex surface treatment consisting of plasma nitriding and PVD hard coating has been widely applied to industrial components to improve their performance and lifetime. This process is also used to enhance adhesion strength and wear resistance property of PVD hard coatings. However the surface compound layer, which is formed by plasma nitriding treatment, causes significant reduction of adhesion property between PVD hard coating and nitrided substrate. In this study, the optimum process condition of plasma nitriding was investigated in order to obtain the best performance of duplex treatment. The PVD hard coatings such as TiN, CrN and Cr-Si-N were deposited by unbalanced magnetron sputtering and their mechanical properties such as hardness, adhesion strength and high speed wear resistance were evaluated. Detailed experimental results including the descrition of high speed tester used in this work will be illuminated.
EP-19 Characterisation and Applications of WC-C Coatings Produced by Magnetron Sputtering
E. Spain, J.C. Avelar-Batista, J. Housden (Tecvac Ltd., United Kingdom)
There are an increasing number of engineering applications for coating that require both good wear resistance and low friction. For example, cam followers for high performance engines, clutch and gear box components for the auto-sport, punches and dies for plastic moulding. In this study, the WC-C coatings were deposited onto AISI M2 steel substrates by magnetron sputtering using a hot tungsten filament for additional ionisation. For all the depositions the coating temperatures were below 523 K. Indention, wear, scratch and hardness tests were performed to assess the mechanical properties of the coatings, and electron microscopy was used to characterise their microstructure. Compared to other industry standard PVD coatings, WC-C has a lower coefficient of friction resulting in better wear resistance. Preliminary trials have shown very good results, in time WC-C could replace some of the industry standard coatings such as TiN and TiAlN in low friction applications.
EP-20 Deposition of Self-Lubricant Nanocomposite Coatings in Air Plasma Spray Process
X. Ma, T. DeCarmine, T.D. Xiao (Inframat Corporation)
Hard ceramic and composite coatings have been used widely for improved wear and corrosion resistances in a variety of application cases, such as diesel engine components for ships, urban buses, locomotives, earth moving vehicles, and power generating stations, and thereby have a strong economic thrush and environmental impact. In comparison to conventional hard coatings, nanostructured ceramic coatings like nano-Al2O3/TiO2 have demonstrated superior performance in terms of wear, erosion and corrosion as well as mechanical properties. In this work, oxide additive acting as "soft" lubricant phase was the first introduced to nanostructured alumina/titania matrix for forming a self-lubricant nanocomposite coating. The nanocomposites had been fabricated into lubricant coatings with a single layer or a functionally graded structure in plasma spray processes. Tribological test results for the nanocomposite coatings demonstrated 4 times increase in sliding wear resistance and 3-5 times increase in abrasive wear resistance in under the tested conditions. The lowest coefficient of friction about 0.18 was measured on the nanocomposite coating with an optimal lubricant (iron oxide or iron sulfide) content in pin-on-disk test in ethanol. Based on morphologies and wear behavior analyses, the wear mechanism was proposed for the nanocomposites. The nanocomposite coatings have exhibited the advantages of cleavability, chemical stability, low friction and high wear resistance, and will have a potential for various applications that require high lubricity at ambient and elevated temperature.
EP-21 Mechanical Properties and Surface Morphology of Sputter Deposited Zr-Ti-Cu-Ni-Be Thin Films
S.N. Sambandam, S. Bhansali, V.R. Bhathanabotla (University of South Florida); D.K. Sood (Royal Melbourne Institute of Technology, Australia)
Thin films of Zr-Ti-Cu-Ni-Be have been studied for their potential technological applications in fields such as MEMS in view of their excellent mechanical properties. Films have been prepared by DC sputtering and their structure, composition, surface morphology, mechanical properties viz., hardness and Young's modulus were analyzed using X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Nanoindentation. Influence of the deposition parameters of sputtering pressure and power upon the composition and surface morphology of these films has been evidenced by Rutherford backscattering Spectrometry (RBS), SEM, and AFM analysis, showing that such a process yields very smooth films with target composition at low sputtering pressures. Crystallization of the films upon rapid thermal annealing about 430 - 600°C yields the formation of Ti, BeTi2, BeCu phases in films contrary to bulk metallic glass. Also, Young's modulus and hardness values were observed to be in the range of 120GPa to 160GPa for both amorphous and crystalline films in contrast to reports on bulk glasses. The results indicate films posses a low Young's modulus (150GPa) compared to silicon, making them better alternatives as flexible microactuators.
Time Period ThP Sessions | Topic E Sessions | Time Periods | Topics | ICMCTF2005 Schedule