ICMCTF2002 Session GP-1: Symposium G Poster Session

Monday, April 22, 2002 5:00 PM in Room Town & Country

Monday Afternoon

Time Period MoP Sessions | Topic G Sessions | Time Periods | Topics | ICMCTF2002 Schedule

GP-1-1 Industrial Applications of PACVD Hard Coatings
C. Lugmair, R. Nöbauer, T. Müller, R. Kullmer (Rübig GmbH & Co.KG, Austria); M. Stoiber (Materials Center Leoben, Austria); D. Reitberger (University of Leoben, Austria); E. Badisch (Materials Center Leoben, Austria); C Mitterer (University of Leoben, Austria)
The advantages of the application of hard coatings, which are well known for cutting tools, are to a much lesser extent explored for casting, extrusion, molding and forming tools. Increasing the lifetime of these tools is an important task in surface engineering because of complex loading conditions and often complicated tool geometry. In all cases, adhesive wear of the mold or die often results in intolerable surface conditions of the product. It has been shown in earlier papers that the plasma-assisted chemical vapor deposition (PACVD) technique is well suited to deposit hard coatings onto large dies and molds. The aim of this study is to present and discuss results obtained on different hard coatings (i.e., TiN, Ti(C,N), Ti(B,N), (Ti,Al)N) in industrial applications for several case studies like pressure die-casting and extrusion of aluminum alloys, deep drawing of sheet steel and plastics molding of polyetherimide. Application-related techniques like hardness measurements, Rockwell indentation test, high-temperature ball-on-disc test, abrasion testing and stress measurements during thermal cycling have been applied to optimize coatings deposited onto hot and cold working tool steels. The results obtained are compared with those of failure analysis of uncoated and coated tools applied in industrial field tests. It was found that a careful optimization of hardness, adhesion, friction and wear properties and compressive stresses is necessary to obtain optimum performance. Typical factors for the increase in lifetime in aluminum pressure die-casting are between 2 and 4, in plastics molding more than 10 and in deep drawing between 13 and 18 with respect to uncoated tools.
GP-1-2 Effect of Additive Gases to C4F8/O2 on Global Warming during PECVD Plasma Cleaning Using a Remote ICP Source
J.H. Kim, J.W. Bae, C.H. Oh (Sungkyunkwan University, Korea); K.J. Kim (Syngkyundwan University, Korea); N.-E. Lee, G.Y. Yeom (Sungkyunkwan University, Korea)
During the PECVD (plasma enhanced chemical vapor deposition) silicon nitride chamber cleaning with C4F8/O2, N2O and NO were added as additive gases for plasma cleaning and the effects of these additive gases and operational condition on the global warming effects were investigated for a system consisted of a deposition reactor and a newly devised remote ICP(inductively coupled plasma) source. Cleaning rate, DRE(destruction removal efficiency), and MMTCE(million metric tons of carbon equivalent) were investigated as a function of the remote ICP operational condition such as rf source power, flow rate, and pressure. In the case of etching or cleaning processing with PFCs(perfluorocompounds), the density of F atom is important in the cleaning of PECVD chamber and, currently, it is difficult to obtain high density of F atoms using a remote plasma source with CxFy/O2 feed gases, therefore, expensive NF3 is used in the remote plasma cleaning, in general. In this study, we tried to use a newly devised ICP to obtain high F atoms from C4F8/O2 in the cleaning chamber and to replace the expensive NF3 remote plasma cleaning system. Also, the emission characteristics of PFCs for the new ICP as a function of additive gases such as NO and N2O were investigated to increase cleaning rate and to decrease MMTCE. Remaining feed gases and emission species such as C3F8, C2F6, CF4, COF2, and COx were observed through the exhaust line during silicon nitride cleaning. Characteristics of cleaning rates and MMTCEs were improved by adding the each additive gas because of the reaction between surface nitrogen and nitrogen oxide(NO) from the N-based additive gases and the increase of destruction efficiency of CxFy through the reaction between nitrogen and fluorine or carbon in the ICP source.
GP-1-3 Characteristic of a Large Area Capillary Electrode Type Atmospheric Pressure Plasma Equipment and It's Application to Surface Treatment
C.H. Yi, Y.H Lee, D.W. Kim, G.Y. Yeom (Sungkyunkwan University, Korea)
In the industrial plasma processes, low-pressure plasmas are dominant in the processing of the materials such as thin film deposition, etching, and surface treatment. However, to generate plasmas at low pressures, costly vacuum equipment and vacuum measurement tools are required, and the use of vacuum in the processing increases the fabrication cost and decreases throughput. If stable glow discharges can be realized under atmospheric conditions in large area, the expensive vacuum equipment and the measurement tools can be eliminated and the throughput can be also increased. Recently, atmospheric pressure glow discharges have been developed as commercial plasma sources for material processing applications. In this study, large area capillary electrode was used to generate atmospheric pressure plasma, and the characteristics and application to material processing such as surface treatment and surface cleaning were studied. To characterize the large capillary type atmospheric plasmas, characterization tools such as a high voltage probe, a current meter, optical emission spectroscopy (OES), and photo-multiplier tube (PMT) as a function of number of capillary hole, the dielectric-material of electrode, the gas combination of He, O2, Ar, N2, etc were used. Surface characteristics after the etching were investigated using the x-ray photoelectron spectroscopy (XPS). By optimizing atmospheric pressure plasma parameters, organics materials such as photoresist on glass were etched with the etch rate close to 200nm/min with less than 5% uniformity in 300mm in length.
GP-1-4 Low-Voltage Solid State Modulator for Industrial Plasma Immersion Ion Implantation and Deposition
K.Y. Gan (City University of Hong Kong); B.Y. Tang, X.F. Wang (Harbin Institute of Technology); P.K. Chu (City University of Hong Kong)
Implant conformality is one of the big advantages of plasma immersion ion implantation compared to conventional beam-line ion implantation. However, a uniform implant dose over a specimen with a complex shape can be achieved only when the treatment parameters are optimized. Our previous work shows that low-voltage, short-pulse, and high-frequency plasma immersion ion implantation and deposition has many advantages with regard to the surface treatment of industrial components with a complex geometry. In this respect, we have developed an economical low-voltage, solid-state modulator for this special application. The prototype developed in our laboratory uses switches made of IGBTs in series. The output voltage can be adjusted from one to ten kV and the pulse width can be varied from 2 to 60 microseconds. The pulsing frequency can go up to 2 kHz but can be pushed higher with better hardware. In addition to presenting our equipment design, we will present experimental data acquired using this modulator.
GP-1-5 Ion beam Assisted Deposition of Magnesium Oxide Thin Film for Optical Applications
A. Ide-Ektessabi, H. Nomura, N. Yasui (Kyoto University, Japan); Y. Tsukuda (Sanwa Kenma Co. Ltd., Japan)
MgO thin film is a potential material for applications in PDP (Plasma Display Panel) technology. In this paper the experimental results on preparation of MgO thin film using ion beam assisted deposition is presented and the effects of simultaneous irradiation of oxygen ion beam is discussed. The films were deposited on Si, Glass, and PET substrates. The deposition rates were about 1 nm per second, and the ion beams current were about a few hundreds µmA/cm2. Stable, transparent, and uniform films of MgO were prepared. The properties of MgO thin films were investigated using XRD, AFM, and RBS. Measurement results on surface nano-morphology, film composition, and crystallinity are presented.
GP-1-6 Characteristics of MgO Thin Films Prepared Using Broad Beam Ion Irradiation
A. Ide-Ektessabi, N. Yasui (Kyoto University, Japan)
MgO thin films have been are widely used in plasma display panel (PDP) production industry. The performance of PDP is strongly influenced by the surface characteristics of MgO thin films. In this paper, in order to improve the characteristics of MgO surface, PVD process with ion irradiation is carried out and investigated in detail. The crystalinity, stoichiometry, and mechanical properties of the MgO thin films were measured by using various analytical methods, such as XRD, RBS, and AFM. When ion irradiation was performed, a linear ion source, which has a slit type ion beam with a length of more than 300 mm and a width in the order of 1 mm, were utilized. Current and energy distribution of the linear ion source have been measured and the results show the good uniformity of the beam.
GP-1-7 Performance Evaluation of AIP-TiAlN Coated Tool for High Speed Machining
Kang Myung-Chang, K.H. Kim (Pusan National University, Korea)
The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained. Unfortunately the development of evaluation technique of life and optimal operation condition of tools is not close by that of tool. Recently the high performance tools like TiAlN coated one have been reported to be well developed from materials point of view. The evaluation of various tools is, however, scarcely reported. In this work, a newly developed evaluation system for cutting tools was introduced where the combination system to measure surface roughness, cutting force, and wear of cutting tools at the same time was established. Several types of flat endmills were prepared according to tool shape in which we concentrated in helix angle, number of cutting edge, rake angle and relief angle. These tools were coated with TiAlN by an arc ion plating(AIP) technique. We also prepared various tools of uncoated, TiN, TiCN, and TiAlN coatings for comparison. It was revealed that the newly developed AIP-TiAlN coated tools showed superior tool-life characteristics to others under high speed machining.
GP-1-8 Optimum Design of Film-substrate Geometry and Film Characteristics for High Performance Diamond Coated Tools
H. Hanyu (Osg Corporation, Japan); S. Kamiya (Tohoku University, Japan); Y. Murakami (Osg Corporation, Japan); M. Saka (Tohoku University, Japan)
Diamond coated tools have a significant advantage in anti-abrasive properties for cutting advanced non-ferrous metal such as high silicon aluminum alloy. However, diamond films deposited on tools easily de-bond off due to severe collision to hard particles in high silicon aluminum alloy. Collision to hard particles induces severe mechanical stress at the cutting edges and repeated collision initiates and extends cracks in the diamond film. Total design of diamond coated tools is examined in this report for the highest cutting performance, for the first time from the view points of both macroscopic film-substrate geometry and microscopic internal structure of diamond films simultaneously to maximize the reliability and durability. Mechanical stress induced by collision of particles in high-silicon aluminum alloy is estimated in various geometry of cutting edges by using finite element method. In the meantime, huge internal stress arises in diamond films because of the mismatch of thermal expansion coefficients of films and substrate materials. Possible concentration of the internal stress is also surveyed around the cutting edges in various geometry. Cutting edge geometry is optimized to minimize the maximum total stress which initiates cracks under repeated collisions of particles. Once optimum geometry is designed, crystalline structure of diamond is then also optimized to maximize the toughness of films to arrest crack extension. Reduction of crystal grain size and positive control of the degree of crystallinity are examined. The toughness of diamond films and internal stress in them are actually measured by the technique recently developed by the authors. By putting together the results above, optimized diamond-coated tools are successfully designed in the most suitable film-substrate geometry and with the best characterized diamond film. They show extraordinary cutting performance against materials which has been difficult to machine, for example high silicon aluminum alloy.
GP-1-9 Performance of Hard Coated Steel Tools for Steel Sheet Drawing
P. Pesch, S. Sattel (TZO GmbH, Germany); S. Woestmann, P. Masarczyk (TKS AG, Germany); K. Herden (Nier GmbH, Germany); T. Stucky (Fraunhofer IWS, Germany); A. Martens (FZK IMF1, Germany); S. Ulrich, H. Holleck (Forschungszentrum Karlsruhe, Germany)
In the present work five different hard coatings have been deposited on five qualities of steel by different means of deposition (CVD, PVD, Arc). Substrates were highly polished planar steel samples on the one hand and special testing-tools on the other hand. Planar steel substrates were used to set up a data table of thin film characteristics such as film thickness, hardness, friction coefficient, adhesion and youngs modulus. Coated testing-tools were used to evaluate their performance in the steel-strip-drawing-test. This testing routine is explained in detail. Three different qualities of steel sheets and two different lubricants were tested. In order to evaluate the compatibility of a hard coated tool for steel sheet drawing two criteria from the steel-strip-drawing-test, the friction coefficient and the stick-slip-effect, were estimated.
GP-1-10 Deposition and Characterization of PVD and PE-CVD Generated Carbon Coatings for Use in Dry Lubricant Applications
J. Liebich, D. Roth, K.H. Dittrich, D. Oelsner (Roth & Rau Oberflächentechnik AG, Germany)

The ecological and economical background in metal cutting industry requires the reduction of Cooling Lubricants (CL).

To avoid the disadvantages of dry cutting operation, combinations of hard coatings with so-called soft coatings - especially carbon films - are very promising. Estimation and comparison of carbon coatings to each other is expensive and critical, because they react very sensitively to the smallest variation of deposition parameters and geometrical sizes. Their properties scatter in a wide range.

In the presented contribution an industrial hard coating machine - equipped with two large area Arc sources - is completed with a magnetron sputtering source (PVD) and a large ECR-plasma source (PE-CVD). The arrangement allows the deposition of hydrogenated pure and metal carbon-diamond or graphite like (with ECR-plasma) as well as of hydrogen-free diamond or graphite like carbon by sputtering.

Compounds of hard coatings (TiN, TiCN, TiAIN), topped with the whole possible range of amorphous carbon coatings, can be deposited on real tools for dry lubricant applications. Lifetime and wear resistance of different cutting tools were investigated and favorite compounds have been found.
GP-1-11 Ion Nitriding as Internal Surface Protection of Pipes a Technological Solution
J. Feugeas (Instituto de Fisica Rosario (CONICET-UNR) and PIPAD-PLADEMA, Argentina); L. Nachez, A. Marenzana (IFIR, Argentina)
Ion nitriding has been proved to be an efficient method to protect the surface of steels to hydrogen permeation [1]. Nevertheless, for several applications like the petroleum and their by-products transport with pipes, the excessive length and the fact that the treatment has to be done in the internal surface, makes difficult the processing in conventional ion nitriding reactors. In this paper an in situ mechanism of ion nitriding is presented with the technological solution for several specific applications. The experimental results in small-scale applications (with pipes of different diameter-length ratios) showed the compound layer development in several times of materials like austenitic and ferritic stainless steels, and AISI 1010 and AISI 4140 steels. The compound layers, between 10 and 25 microns, followed by thicker diffusion layers present the characteristics of well-structured layers as hydrogen permeation barriers. The modification in the geometry of the normal ion nitriding configuration done in this case did not showed significant changes in the kinetic of the discharge, as it was investigated using the real time and in situ optical emission spectroscopy [2].
GP-1-12 Hot-dip Aluminizing of Steel
H. Jafari (Shahid Rajaee University, Iran)
In recent years, iron-aluminum and other bimetallic parts, including those with a metallic diffusion bond between dissimilar metals, have been wildly used. The aluminum-coated ferrous materials exhibit higher environmental corrosion resistance, high thermal conductivity and good heat and wear resistance. All these properties are obtained by effective aluminizing of steel. In this research, it has been tried to obtain optimum condition of hot-dip aluminizing and a good aluminum coating on steel. In this way, a variety of flux formulations either aqueous or molten were tested. Subsequently, temperature, dipping duration and angle and speed of withdrawal of specimens were examined. After achieving effective aluminizing and good aluminum coating, the surface appearance and corrosion resistance of aluminized steel were examined.
Time Period MoP Sessions | Topic G Sessions | Time Periods | Topics | ICMCTF2002 Schedule