Papers

ICMCTF1999 Session G5: Hard and Hybrid Coatings: Cutting, Forming, Autolubricated Tools and Machine Parts, Upscaling of Coated Parts

Monday, April 12, 1999 8:30 AM in Room Town & Country

Monday Morning

Start	Invited?	Item
10:30 AM		G5-7 Challenges and Opportunities for Surface Engineering with Thin Film Processes P. Hatto (Multi-Arc Inc., UK) Surface engineering with vapor deposited thin films is making the transition from the traditional realm of tool coating to a much broader range of, component based, applications where significant market opportunities exist. Such changes are occurring partly as a result of increased awareness of the benefits that thin films can confer and partly as a result of the availability of new coating architectures. Because of the severe environment encountered by tool coatings, life expectations are relatively short. With new applications, such as biomedical, automobile, aerospace and decorative, life times are measured in years rather than minutes or hours. Components typically fall into one of two categories: either they are high cost and are coated in relatively small numbers; or they are produced in large quantities, albeit to frequently very high tolerance, and must be coated at relatively low cost. With the exception of decorative applications, the coating is normally critical to the operation of the final system. Any failure of a coating to perform as expected may, at best, necessitate costly strip-down of the system of which it forms part or, at worst, lead to premature failure of a system that is worth many orders of magnitude more than the original cost of coating. Concerns about operational failure provide coating organizations with significant challenges for quality assurance and control which, in turn, need to be addressed by standards and specifications development. Meeting such challenges head-on is essential if the industry is to achieve significant penetration in such technically demanding but financially lucrative market areas.
11:10 AM		G5-9 Advanced Complex Coating Systems for Cutting Applications T. Leyendecker, G. Erkens, R. Wenke, H.-G. Fuss, O. Lemmer, St. Esser (CemeCon, Germany) Coatings and tool material have received a clear innovation push from the increased requirements in modern manufacturing processes such as high performance machining, dry processing, high-speed cutting, hard cutting and machining graphite. To meet all these sophisticated demands crystalline diamond coatings, hard multi-layer coatings with integrated lubricious layers, complex oxidation-resistant coatings based on TiAlN and lubricious top layer coatings are developments in the field of coating technology. The experiences from cutting with modern coatings have shown that there is no universal solution as regards the coating material. Similar to the selection of the base material the coating and the microgeometry must be adapted. Substantial advances recently have been made using micro conditioning, r.f. plasma etching and High Ion Sputtering (H.I.S.) process technique. Depending on the application coatings are exposed to abrasive, adhesive or to oxidation loading. Depending on the work piece a correspondingly matched coating that also takes the economic viewpoint of the cutting process into consideration must be used. The fascinating properties of advanced coating systems deposited with modern process technique such as TiAlN based PVD coatings, lubricious layers and diamond films are illustrated for various applications.
11:50 AM		G5-11 Microwave PECVD Source for Deposition Up to 1 Bar Pressure R. Spitzl, W.-D. Voigt (Iplas Innovative Plasma Systems GmbH, Germany); A. Becker (Iplas Innovative Plasma Systems GmbH); H. Sung-Spitzl (Iplas Innovative Plasma Systems GmbH, Germany); M. Cichos (Iplas Innovative Plasma Systems GmbH, NRW) For commercial applications of PECVD processes quality of the tools and production rate are of crucial interest. Therefore process-time and deposition rate are the drivers for an efficient production. One essential parameter for the deposition rate of PECVD processes can be found in the gas pressure. This is often limited by the plasma generating device. Increasing pressure leads to a domination of gas-phase interaction over the gas-wall interaction which is typical for low pressure plasmas. The consequence is a concentration of the plasma in areas of highest field density. These effects can be compensated partly by increasing the microwave power which until now resulted in thermal damage of the deposition equipment. To overcome these problems the new CYRANNUS plasma source has been designed with a special resonator configuration. Making it capable to be run from low pressure up to atmosphere and even beyond. At atmosphere (air) a homogenous plasma with a diameter of more than 100 mm can be achieved requiring no more than 3-4 kW microwave power. The application field of the new CYRANNUS plasma source is discussed with the example of a PECVD diamond process for various uses.