ICMCTF2006 Session GP: GP Poster

Thursday, May 4, 2006 5:00 PM in Room Town & Country

Thursday Afternoon

Time Period ThP Sessions | Topic G Sessions | Time Periods | Topics | ICMCTF2006 Schedule

GP-1 Compositionally Graded CrAlN Coatings by Reactive Magnetron Sputtering
S. Pulugurtha, A. Aditya, A. Khanna, D.G. Bhat (University of Arkansas)
PVD CrAlN coatings have high potential as wear and corrosion resistant functional coatings for cutting tools. These films were deposited using an inverted cylindrical magnetron sputtering system (ICM-10) with chromium and aluminum targets on various substrates. The unique arrangement of the targets permits deposition of compositionally graded coatings in which the Cr/Al ratio can be varied systematically from a Cr-rich to an Al-rich binary nitride coating. The present study focuses on the effect of various deposition parameters, such as the N2/Ar ratio and the target power on the properties of the coatings obtained. The coatings were deposited at a chamber pressure of 1.5 mT for 1.5 hrs. The microstructures of these coatings were investigated by various analytical techniques such as XRD, ESEM, and EDS. In this paper, we report on the effect of processing parameters on the microstructure, crystallography, composition and oxidation behavior of the compositionally graded (CrxAl1-x)N coatings.
GP-4 Corrosive Behavior of Amorphous and Crystallized Chromium Carbide Coatings Deposited on Steel by Filtered Cathodic Vacuum Arc Deposition
C.-C. Lin, K.-L Chang, W.-J. Hsieh, H.-C. Shih (National Tsing Hua University, Taiwan)
The deposition of chromium carbide film on steels by 90o-bend filtered cathodic vacuum arc (FCVA) has great potential for industrial applications, because chromium carbide films are free of macroparticles and exhibit excellent characteristics. In this study, the C2H2/Ar ratio of the reactive gas was controllable to synthesized the amorphous and crystallized chromium carbide films from Cr target (99.95%) with a substrate voltage of -50 V at 500°F. The corrosion behavior of the amorphous and crystallized chromium carbide coatings deposited on steel were compared in terms of open-circuit potentials (OCP) and polarization resistance (Rp), as determined by electrochemical impedance spectroscopy (EIS) in an aerated 3.5 wt% NaCl aqueous solution. The results demonstrate that the nanostructure of the chromium carbide film depended on the C2H2/Ar pressure as the C2H2/Ar ratio of the reactive gas decreased from 6.1Ã-10-3 to 2.9Ã-10-3 Torr and the phase was transformed from amorphous (a:CrXCy) to crystallized (Cr3C2) structure The OCP of the a:CrXCy/steel and Cr3C2/steel are nobler than those of the uncoated steel and the Rp of the coatings exceeds that of uncoated steel. The EIS results indicate that Cr3C2/steel more effectively isolates the defects of the a:CrXCy/steel. Keywords: a:CrC, Cr3C2 , FCVA, EIS, corrosion resistance.
GP-5 Friction and Wear of Polymeric PET-EMAA Composite Coatings Deposited by Thermal Spray
G. Custodio, J.R.T. Branco (Technological Center of Minas Gerais Foundation, Brazil)
The polymer industry if of great importance to the contemporary lifestyle and its range of application is being extended with the development of polymer based composites. Among the various valuable applications for such materiais there are those for bio-implants, for what the use of poly(ethylene terephthalate)-PET based composites shows potential. In this paper a study of pin-on-disc sliding wear and friction behavior of PET, -EMAA- and (PET/EMAA) composite, with 3 levels of EMAA, coatings deposited by combustion thermal spray processing is presented. The thermal sprayed coatings and composites provided significant corrosion protection to steel, as measured by salt spray testing. The spraying process promoted the wear resistance of the PET, which presented friction coefficient as low as 0,07, while the increase of EMAA to 30% weight resulted in an increase of these characteristic to values higher than 0,25. This results are discussed based on measuarements of microhardness, nannoindentation, profilometry, light and scanning electron microscopy, DSC and XRD.
GP-6 Internal Linear Inductively Coupled Plasma Source Using Parallel Type Antenna for the FPD processing
J.H. Lim, K.N. Kim, G.Y. Yeom (Sungkyunkwan University, Korea)
Inductively coupled plasmas (ICP) have been investigated for the processing of various materials as one of the high density (1011~1012 cm-3) and low gas pressure plasma sources. Especially, ICP is one of the most attractive source among the various high density plasma sources due to the advantages of simple physics and a simple source structure with easy scaleability to large size. In this study, characteristics of an internal linear inductively plasma source was investigated as a possible high density plasma source for the application to flat panel display processing larger than 7th generation of TFT-LCD substrates. By varying the arrangements and distance of the antenna arrays, the uniformity of the plasma has changed significantly, and, by optimizing the antenna arrangement, the good plasma uniformity was obtained on the substrate. Electrical characteristics of the plasma source measured by an impedance analyzer showed the low impedance and high power transfer efficiency for the optimized antenna arrangement.
GP-8 Mechanical Properties and Cutting Characteristics of Nano-Composite Ti-Al-N Coated Tools by Filtered Arc Ion Plating in High Speed Dry Cutting of Hardened AISI D2 Steel
D.H. Kwon, J.H. Kim, M.C. Kang (Pusan National University, Korea); K.I. Moon (Korea Institute of Industrial Technology, Korea); Y.H. Jeon (J&L Tech. Co., Ltd., Korea)
Ti-Al-N coatings with several Ti / Al ratios were deposited on the WC-Co substrates by filtered arc ion plating method. The ratio of Ti / Al composition, the pressure and the flux of nitrogen were changed during the depositon. The effects of third elements such as Si, Cr, B on the formation of nano-composite were also studied. The resulting microstructure were multilayered structure with the layer thickness less than 50 nm, intra/inter type and nano/nano type nano-composites with grain size less than 50 nm. The micro-hardness of nano-composite coating was over 40 GPa. The thermal stability, oxidation resistance and mechanical properties were characterized in terms of their phase composition, nanostructure. The proper nano-composite coatings with high hardness and high thermal stability were deposited on the tungsten carbide end-mills and their cutting performance and tool life under high-speed cutting condition were also evaluated in this work.
GP-9 Corrosion Performance of Duplex Treatments Based on Plasma Nitriding and PAPVD TiAlN Coating
S. Liscano, L.E. Gil (UNEXPO, Venezuela); M.H. Staia, M. Cruz (Central University of Venezuela); O.A. León (UNEXPO, Venezuela)
Duplex treatments consisting of a plasma nitrided layer followed by a PAPVD hard coating have gained attention in recent years. The aim of this work was to determine the corrosion resistance of AISI H13 steel treated by using this duplex treatment. The samples were pre-nitrided using an experimental equipment and, subsequently, coated by PAPVD by using a commercial procedure. A series of electrochemical tests such as potentiodynamic polarization and linear polarization were carried out to investigate the response to the corrosion behavior of the steel due to this duplex treatment. Surface characterization before and after corrosion testing was performed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDS). The experimental results indicate that TiAlN coating protects the substrate against corrosion and this behavior was attributed to the passivation of the iron nitride sublayer formed during the plasma nitriding process
GP-10 Corrosion Performance of Plasma Nitrided 316L Stainless Steel
L.E. Gil (UNEXPO, Venezuela); S. Brahl (Universidad Tecnologica Nacional, Facultad Regional Concepcion del Uruguay, Argentina); M.H. Staia (Central University of Venezuela); O.A. León, L. Jimenez (UNEXPO, Venezuela)
Stainless steel 316L has been widely used in artificial knee or hip joints, as well as internal fixation devices. It is well know that this material has a good corrosion resistance and very good biocompatibility properties. Ion nitriding is a well established process for steel hardening that can also be applied to this kind of steels with the aim to enhance its hardness but without reducing its corrosion resistance. In this work, the effects of ion nitriding on the corrosion performance of a 3l6L stainless steel was evaluated in a 3.5 % sodium chloride solution by using electrochemical tests such as potentiodynamic polarization and linear polarization in both nitrided and untreated AISI 316L steel condition. Surface characterization before and after corrosion testing was performed using scanning electron microscopy (SEM) with an energy dispersive X-ray analysis (EDX) and Auger electron spectroscopy (AES). X-ray diffraction (XRD) was used to identify the phases formed in the nitrided zone. It was shown that an ion nitriding treatment in a 25% N2-75% H2 atmosphere, at a controlled temperature of 410°C improves the hardness and the corrosion resistance of the 316L stainless steel by forming a modified layer consisting of nitrogen expanded austenite, which retains the ability of the substrate to form protective oxides films.
GP-12 Mechanical Properties and Cutting Performance of Cr-Si-N Coated Micro End-Mill Tool in the Machining of Ductile Materials
I.S. Kang, M.C. Kang, J.S. Kim, K.H. Kim, J.T. Ok (Pusan National University, Korea)
Ultra-precision machining and MEMS technology have been taken more and more important position in machining of micro-parts. Micro machining is one of the prominent technologies that has wide spectrum of application field ranging from macro parts to micro products. In this work, comparative studies on mechanical properties and cutting performance between CrN and Cr-Si-N coatings were conducted. Ternary Cr-Si-N coatings, in which Si was incorporated into CrN, were synthesized onto WC-Co substrates using a hybrid system of arc ion plating and sputtering techniques. The high hardness of Cr-Si-N coatings was related to the composite microstructure consisting of fine CrN crystallites and amorphous Si3N4. The average friction coefficient of Cr-Si-N coatings gradually decreased with increase of Si content in CrN coatings. Cutting tests were carried out to evaluate the characteristics of high-speed cutting using a Mikino V55 high speed machine tool with Cr-SiN coated micro-tool having tool diameter 200 µm. In addition, an environmentally conscious cutting through oil mist method of lubricant-free cutting was applied in this work.
GP-13 The Failure Mechanism of Diamond Like Coatings Prepared by the Filtered Cathodic Arc Technique for Minting Application
W. Lin (Central Mint, Taiwan); M.-S. Leu (Industrial Technology Research Institute, Taiwan); C.-Y Su (National Taipei University of Technology, Taiwan)
The wear resistance and the failure mechanism of hydrogen-free amorphous diamond like carbon (DLC) thin films prepared by filtered cathodic arc deposition technique for proof mint applications are reported. Emphasis is placed on the lifetime of the proof minting dies coated with DLC coatings, which can extend about 8 and 4 times corresponding to that of un-coated and hard chromium plating dies. Due to the DLC coating characteristic thereof maintain a high degree of surface smoothness of the proof minting dies after coining process. The failure mechanisms of DLC film for coining process are (1) The locally micro-cracks and the film breakdown were found due to the surface pin hole of DIN2550 which results in poor adhesion between the DLC coating and substrate. (2) the plastic deformation of substrate materials results in die sinking and/or die settling (necking expansion), sometimes the thin film breakdown were observed due to obviously plastic deformation of substrate. (3) The inclusion on the blank results in high-stress abrasion and/or impact wear.
GP-14 Fatigue Properteis of a SAE 4340 Steel Coated with TiCN by PAPVD
E.S. Puchi-Cabrera, M.H. Staia, E. Ochoa-Pé ez, J. La Barbera-Sosa, C. Villalobos-Gutiérrez (Central University of Venezuela); G. Mesmacque (University of Science and Technology of Lille, France)
The fatigue behavior of quenched and tempered SAE 4340 steel has been investigated, both in air and in a NaCl solution, before and after coating the material with a film of TiCN deposited by PAPVD. The samples were coated industrially at Balzers with a film of BALINIT® B of approximately 3 microns in thickness and the fatigue tests were carried out under rotating bending conditions, at alternating stresses in the range of 539-695 MPa, depending on the condition of the material. In this way, it was possible to determine the Wöhler curves for the uncoated and coated samples, in order to evaluate the effect of the TiCN film on the fatigue and corrosion-fatigue properties of the substrate. However, prior to fatigue testing, the static mechanical properties of the uncoated and coated material were evaluated by means of tensile testing. The results of such an evaluation indicated that the presence of the film gives rise to a slight increase of about 10% in the yield strength of the steel but also a slight decrease of about 12% in its tensile strength, in comparison with the uncoated substrate. It has been observed that the presence of the film also gives rise to a significant increase in the fatigue life of the coated specimens, when these are tested in air. Such an increase varies between 135-175%, depending on the alternating stress applied to the material. Also, the fatigue limit of the steel was observed to increase by 6% after coating. On the contrary, under corrosion-fatigue conditions at alternating stresses in the range of 539-696 MPa, the fatigue life either decreased slightly or remained unchanged in relation to the uncoated samples. The fractographic analysis conducted on selected samples tested both in uniaxial tension and fatigue, indicated that the coating remains well adhered to the substrate even under the most severe conditions of testing, as well as high fracture strength.
GP-15 Antibacterial Effects of Silver-Coated Acrylonitrile-Cutadiene-Styrene by Metal Vapor Vacuum Arc
S. Han (National Taichung Institute of Technology, Taiwan); H.-Y. Chen (Asia University, Taiwan); Y.-C. Chen, M.-W. Huang (National Chung Hsing University, Taiwan); T.-N. Yuan, J.-C. Chang (National Taichung Institute of Technology, Taiwan); H.-C. Shih (National Tsing Hua University, Taiwan)
This study employed a metal vapor vacuum arc (MEVVA) system to deposit a silver thin film onto the substrate of acrylonitrile-cutadiene-styrene (ABS) which has been known for its applications in telephone handsets computer and other office equipment housings. The morphology, crystal structure, and chemical composition of the depositions are investigated using FESEM, TEM, XRD and XPS, respectively. The dissolution of silver into its ions was monitored by the electric resistivity as well as the atomic absorption spectroscopy. The presence of a large number of nano-scale Ag with SAD pattern was revealed. Moreover, the antibacterial activity against gram-positive staphylococcus aureus (S. aureus, ATCC 6538) was evaluated in depth and found that an excellent antibacterial performance of the silver-coated ABS against S. aureus was demonstrated.
Time Period ThP Sessions | Topic G Sessions | Time Periods | Topics | ICMCTF2006 Schedule