Scale-up, Manufacturing Aspects and Industrial Applications of Coatings
Tuesday, April 11, 2000 1:30 PM in Room Town & Country
G2-1 The Application of Quantitative Modeling Techniques to the Problems of New Business Development: Marketing of New Deposition Technologies
T. Mascarin (IBIS Associates)
In order to achieve commercial success, alternative material systems must offer a favorable balance of performance and economics relative to incumbent products. In the technology development cycle, it is not uncommon for a great deal of excitement to surround a new material formulation or application that promises improved functionality. Unfortunately, it is almost just as often that such new technology efforts fail to succeed because of unfavorable economics, either because of cost factors inherent in the process, or market factors such as economies of scale required for market-entry pricing. In either of these cases, it is exceedingly valuable for the developers to understand the existing and potential cost structures, in order to make the most effective strategic decisions and allocation of resources. This paper reviews the use of quantitative techno-economic analysis techniques, such as Technical Cost Modeling, and their application to technology and business development strategies. Specifically, the paper will focus on the methodology of, and the benefits derived from, applying these techniques to improving commercialization strategies for coating and deposition technologies. Technical Cost Modeling, Quantitative Business Assessment, and Value Chain Analysis will be discussed, with examples drawn from the business development experience of the authors.
G2-3 Considerations for Application of Engineered Surfaces in Heavy Duty Equipment
P.H. McCluskey (Caterpillar Inc.)
Surfaces are the key to the performance of many commercial products. Specifically, product life is often dictated by the component with the least durable surface. Wear, corrosion, fracture, and plastic deformation can degrade component surfaces. Oftentimes, more than one of these mechanisms is active simultaneously. Surface engineering is the name recently given to the ancient discipline of stopping or delaying these surface damage mechanisms. Surface engineering solutions include such techniques as painting, hardfacing, and heat treating. Because these specific approaches have a long history, they currently advance in an evolutionary way. Industry is seeking to improve surface durability in a revolutionary way. Because of its relative youth, thin film PVD coatings offer such an opportunity. The revolutionary opportunities and benefits of PVD coatings will be discussed, with a focus on application in heavy industry. Also addressed will be the shortcomings that must be resolved prior to broad, industrial insertion of PVD coatings onto components.
G2-5 Theory and Practice in Future Industrial Development of PVD Hard Coatings for Modern Machining Applications
H.K. Zimmermann, V. Derflinger, D.T. Quinto (Balzers Ltd., Liechtenstein)
Modern PVD processes are suitable to coat tribologically highly stressed tools with dimensionally controlled deposition of thin wear-resistant coatings at low temperatures that do not affect the substrate material. Present research work in coating technology is spread over a wide area, including the development of new fields of application as well as the redesign and further development of coating processes. Coating materials are constanlty being extended to develop coating-substrate combinations adapted to special applications. The possibilities seem to be almost unlimited, taking into account not only compositional additions but also multilayered and gradient coating structure variants. This paper presents a perspective on these actual trends in coating development to point out that in fact there are only a few main development directions that are practical. Each direction is focused on special improvements. Although the possibilities to improve coatings are often common knowledge, the industrial development of new hard coatings is limited by design and cost constraints. Using examples from the development of PVD coatings for machining applications this paper tries to explain this situation.
G2-7 Characterisation of Large Area Filtered Arc Deposition Process
V.I. Gorokhovsky (Aromac Plasma Processing Lab, Canada); D.G. Bhat, R. Bhattacharya (UES, Inc.)
The propagation of plasma flow in rectangular dual filtered arc source is investigated. The characteristic parameters of plasma flow, such as ion current yield and inter electrode voltage drop vs gas pressure are established for the deposition of TiN coatings. The uniformity and productivity of coating deposition on complex parts in a 3D operational volume is determined. It is found that ion current yield increases from 6 to 10 amp with increasing argon pressure in the range of 2 to 7x10 @super -2@ Pa. It results in a deposition rate on the order of 1 to 2 µm/hr in a double rotation mode. It is shown that a thickness uniformity of @+/-@10% or better can be achieved in a programmable vertical scanning mode.
G2-9 Optimization of the Cutting Edge Radius of Multi and Monolayer PVD Coated Inserts in Milling Considering Film Fatigue Failure Mechanisms
K.-D. Bouzakis, N. Michailidis, N. Vidakis (Laboratory for Machine Tools and Manufacturing Engineering, Mechanical Engineering Dept., Aristoteles University of Thessaloniki, 54006, Greece); T. Leyendecker, G. Erkens, R. Wenke, H.-G. Fuss (CemeCon, Germany)
The fatigue failure mechanisms of PVD coatings in interrupted cutting processes are comprehensively detected in this paper. The fatigue and the wear behavior of single and multilayer coatings on cemented carbides substrates are investigated experimentally in milling and analytically through a Finite Elements Method simulation of the cutting process. Various cutting inserts with different cutting edge radii were examined. The initiation and progress of the tool failure is depicted through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray microspectral investigations of the used cutting edges. Furthermore, the FEM simulation of the contact between the tool and the workpiece enables a quantitative description of the influence of mechanical stress components on the coating failure. Hereby, already existing critical coating fatigue stresses and experimentally derived technological cutting data were considered. The experimental and computational results exhibit quantitatively the effect of tool radius on the overall cutting performance as well as the influence of the coating fatigue behavior for various substrates and film structures. To make though use of the superior characteristics that coatings give to improve the cutting performance, it is highly recommended to optimize the cutting edge radius of the cutting insert itself to avoid early coating failure and consequent wear development.
G2-10 Combined Cathodic Arc/Unbalanced Magnetron Grown CrN/NbN Superlattice Coatings for Applications in Cutlery Industry
P.Eh. Hovsepian, W.-D. Münz (Sheffield Hallam University, United Kingdom); A. Medlock (Cutlery and Allied Trades Research Association,CATRA, United Kingdom); G. Gregory (Cutlery and Allied Trades Research Association, CATRA, United Kingdom)
Hard CrN/NbN superlattice coatings (@delta =@ 2.7 nm. ) have been grown at low temperatures (250 0C) by combined cathodic arc/ unbalanced magnetron techniques to coat knife blades produced from 1@%@ carbon steel in an industrially sized 4-target PVD coater. The deposition process combines the advantages of the metal ion etching by Cr+ ions generated by steered arc discharge to guarantee high adhesion and unbalanced magnetron sputtering to deposit smooth CrN/NbN superlattice coatings. The coatings structure, residual stress, phase and the chemical composition have been investigated by XRD, SEM, X-TEM and SNMS techniques. The XRD and hardness measurements confirmed that the temperature treatment during the deposition process did not deteriorate the initial properties of the blade material. It has been found that both the initial sharpness and the wear performance of the blades depend on the coating thickness and coating stoichiometry. CrN/NbN coatings with stoichiometric composition and thickness in the range of 3µm showed the best compromise between initial sharpness and edge retention according to ISO cutting standards. Low temperature CrN/NbN superlattice coated craft and textile blades showed an increase in lifetime by factor of 10 when compared with uncoated ones and currently used Cr2O3 coated textile blades. The CrN/NbN showed similar wear resistance to a TiAlCrYN coating and was superior to commercially available CrN and various C based PVD coatings tested under the same conditions.
G2-11 Dedicated PVD Arc Coatings for Industrial Applications
H. Curtins, J. Rechberger (Platit Ag, Switzerland)
TiAlN coatings can be produced in a wide variety of compositions and structures exhibiting strongly different properties. Therefore, depending on the type of application, these properties have to be carefully choosen and optimized. These dedicated coatings can dramatically outperform similar coatings designed for conventional broad-band applications. Based on industrial key operations such as milling of Ti-alloys and dry drilling of automotive components this outperformance potential will be illustrated. However, the industrial implementation of such a concept is not realistic with conventional coating systems. We will shortly discuss dedicated coating equipment that allows to exploit todays industrial need for peak performance.