Papers

ICMCTF1999 Session G2: Scale-up, Manufacturing Aspects and Industrial Applications of Coatings

Tuesday, April 13, 1999 8:30 AM in Room Town & Country

Tuesday Morning

Start	Invited?	Item
8:30 AM		G2-1 Commercialization Barriers for Engineered Surfaces: Opportunities in the Advanced Technology Program C.M. Allocca (NIST / Advanced Technology Program) The NIST Advanced Technology Program (ATP) is a unique partnership between government and private industry to accelerate the development of high-risk technologies that promise significant commercial payoffs and widespread benefits for the economy. In the area of engineered surfaces, the ATP currently has a portfolio of nine industry-led projects, with estimated federal funding of over $25 million that leverages over an additional $27 million of cost-shared industry funds committed over 2-5 years. ATP stays in continual contact with the surface engineering community in order to better understand industrial needs--this is turn aids the identification of technologies appropriate for future ATP funding. Our recent interactions suggest that, due to individual priorities and availability of resources, today's approach to surface development tends to be empirical and specific to a component and/or materials system. As a result, industrial knowledge consists of a set of point solutions that have made it difficult to develop new opportunities that are not similar to a previous application. Future ATP funding could offer the opportunity to shift the industry from point solutions to a structured approach, ultimately moving the status of surface modification from that of life enhancement to the enabling goal of extreme predictability and reliability. The strategy to enable this shift would be the creation of a set of tools, including, but not necessarily limited to, high-risk innovative approaches to life prediction, plasma diagnostics, modeling, equipment development, non-destructive evaluation, and in-line process control. This presentation will, after a brief overview of the program, describe the current projects and the status of industry's view of new ideas ready for ATP funding.
8:50 AM		G2-2 Scale-up of Pulsed Laser Deposition - Is it Ready? J.S. Zabinski (Air Force Research Laboratory) Pulsed laser deposition and its variants have proven very useful for depositing coatings with unique and singular characteristics. The technique is especially useful for depositing coatings at low temperature. This is particularly important for eliminating substrate damage of tribological materials where precise tolerances and microstructures must be maintained. Stoichiometry of target materials can be readily reproduced even within oxide systems which can be difficult to grow using other techniques. Variants of PLD, such as magnetron assisted PLD, permit growth of functional gradients, multilayers, and nanocrystalline composites. These architectures allow production of coatings with superior properties. Superconductors, ferroelectric, ferrielectric, and piezoelectric materials with exceptional properties have also been produced. So far, PLD has been largely used as a research and rapid coating design tool. Some success has been reported for marketing x-ray mirrors. The technique is not used in manufacturing because the scale-up process has not been completed. Scale-up issues of most importance include coating large parts, complex shapes, and developing feedback process controls. A market where PLD coatings can successfully compete must be identified before commercialization and cost reduction efforts will be considered. Discussion focuses on materials and processes (PLD and variants) that warrant a scale-up effort. Cost issues will be addressed as well as recent efforts to build second generation coating systems with process controls.
9:30 AM		G2-4 Applicability of Different Hard Coatings in Dry Machining an Austenitic Steel M. Lahres, R. Neumüller (Daimler-Benz Company, Germany); O. Doerfel (University of Karlsruhe, Germany) Today, a high proportion of machining processes is conducted with coolants. In this way, the workpiece, tool and machine tool are cooled, friction processes are reduced and the manufactured chips are removed from the cutting area. Unfortunately, coolants are dangerous for the environment and human health. Moreover, the disposal costs for used coolants are going to explode. Therefore, the movement towards green manufacturing cutting operations will be one of the most important challenges in the near future. Decreasing the costs of the cutting process and the associated reduction of environmental pollution by dry machining is the main key to remain competitive and profitable. In this contribution, results are presented to introduce dry machining of synchronizing cones for automotive applications. Different CVD-/ PVD - commercial coatings were investigated in preliminary investigations for their suitability in dry machining the specific austenitic steel. It will be shown, that coating systems (like hard/ soft) exhibit a great potential for such operations, even under a minimal lubricant system. Furthermore, several parameter studies were done towards accuracy to size, workpiece structure and process stability. Finally, field tests were done performed on this results.
9:50 AM		G2-5 Extended Application Ranges by New Hard/Lubricant Tool Coating V. Derflinger, H. Zimmermann, M. Grischke, D.T. Quinto (Balzers Ltd.) The combined functionality of wear-resistant and low-friction multilayer coatings has widened application possibilities for a new generation of coated tools. For the first time tool wear mechanisms are comprehensively addressed both at the cutting edge and contact areas away from the edge where chip evacuation is facilitated. Since its recent market introduction a combined TiAlN and WC/C PVD coating has been proven to increase cutting performance in various metalcutting operations, notably drilling and tapping of steels, cast iron and aluminium alloys. Significant improvements have been obtained under dry as well as minimal lubrication conditions. Metalforming applications are also under investigation. The result of laboratory metalcutting tests and field trials to date will be described. Correlations between chip formation, wear mechanisms and coating properties are given to explain the realized effectiveness of this coating.
10:10 AM		G2-6 High Volume PVD Coating of Precision Components of Large Volumes at Low Process Costs M. Hans, M. Grischke, M. Zaech, R. Hobi, R. Buechel (Balzers Ltd., Liechtenstein) Balzers has successfully applied the WC:C coating Balinit C in recent years to reduce wear of precision components, mainly for automotive parts. Coating of precision components requires high volume throughput, high process reliability and lower costs to fulfill the price demands of customers. In general, Balinit C is deposited by reactive sputtering in a batch coater, wherein up to 50 % of the production costs are determined by the process costs. The main disadvantages of a batch coater are the time-consuming and non-productive process steps like pumping and venting of the vessel, conditioning of the substrate surface prior to coating and cooling of the substrates. Therefore, Balzers realized a cluster-type in-line machine concept with dedicated process chambers that allows deposition of coatings with high throughput at low costs of ownership. The prototype of the machine and first results are presented.
10:30 AM		G2-7 Technology Insertion: Replacement of Electroplated Chromium With HVOF Thermal Spray Coatings in Manufacturing and Maintenance of Military Aircraft B.D. Sartwell (US Naval Research Laboratory) A program is being executed to qualify WC/Co and WC/CoCr coatings deposited using the high-velocity oxygen-fuel (HVOF) thermal spray technique as replacements for hard chrome plating that is currently being used in both manufacturing and repair of US Defense Department aircraft components. The objectives of this program are to demonstrate superior performance and reduced application and overall life-cycle costs of the HVOF coatings as compared to hard chrome. Several individual projects based on types of aircraft components are being executed, including landing gear, propeller hubs, hydraulic actuators, and components specific to rotary wing aircraft. Joint Test Protocols have been prepared which include appropriate coupon tests (e.g., fatigue, wear, corrosion) combined with full-scale component rig and flight testing. The Canadian Government, together with Canadian landing gear manufacturers, are partnering with the US project team (designated Hard Chrome Alternatives Team (HCAT)) to execute a similar project. Results will be presented for the fatigue, wear, and corrosion studies conducted to date, which generally indicate superior or equivalent performance for the HVOF WC/Co coatings as compared to hard chrome. Information will also be presented on the development of standards and specifications for the HVOF coatings, which is being executed in cooperation with the SAE Aerospace Metals Engineering Committee.
11:10 AM		G2-9 Commercialization of Ion Beam Deposition Systems for Multilayer Coatings and Diamond-like Carbon Deposition A. Hayes, H. Hegde, B. Druz, V. Kanarov (Veeco Instruments Inc.) Within the last few years, ion beam deposition (IBD) techniques have expanded from the R&D labs and specialty optical production houses to largescale manufacturing. This transition is being driven primarily by the needs of the data storage industry for improved methods of manufacturing thin film magnetic head devices. One process involves direct ion beam deposition of diamond-like carbon films as protective and corrosion-resistant coatings, using an ion source operated with a carbon-containing gas. These DLC films must be continuous and exhibit favorable properties at thicknesses of less than 5 nm. Ion beam sputter deposition (also known as secondary IBD) of multilayer film structures is being incorporated in the production of critical magnetoresistive sensor elements of thin film magnetic heads. Also, the demand for commercial IBD optical coating systems is growing. In this paper, we will first review the requirements for these applications, such as uniform deposition areas, deposition rate, and optical and magnetic film properties. We will then describe the advantages of ion beam deposition techniques, the current capabilities of the existing technology, and areas for future development.
11:30 AM		G2-10 Diamond-like Carbon Coatings Prepared in a Bipolar Pulsed D.C. Plasma E.H.A. Dekempeneer, J. Meneve, L. Eersels (Vlaamse Instelling voor Technologisch Onderzoek - VITO, Belgium) High quality diamond-like carbon (DLC) coatings can be routinely produced in r.f. (13.56 MHz) based capacitively coupled plasma assisted chemical vapour deposition (PACVD) reactors. In practice, this process is limited to relatively small batchvolumes (< 1 m³). Bipolar pulsed d.c. processes may offer an alternative to move forward to large scale processing. In this work, DLC coatings were deposited from CH₄ using an asymmetric bipolar pulsed d.c. powersource. The positive pulse was fixed at a low voltage of +75 V, while the negative pulse amplitude was varied between -300 V and - 1500 V. The following coating properties were characterized: C-H and C-C bonding structure using Fourier transformed infrared (FTIR) and Raman spectroscopy, hardness using depth sensing indentation, internal stress using the bending beam technique. Substrate heating during deposition was evaluated using the annealing characteristics of hardened 100 Cr 6 steel pins. These properties are correlated with the major variables of the power supply: pulse frequency, pulse amplitude and duty cycle.