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Advanced cutting tool coatings

The project aims to develop enhanced coated tools with
improved wear-and-tear resistance for cutting applications
based on an extended coating characterization procedure
using advanced experimental and analytical methods.

The enhanced manufacturing demands based upon the improved capabilities of modern machine tools require the persistent development of superior materials for cutting tools. Today, advanced and complicated techniques are widely used in production of thin hard coatings, increasing in this way the variety of the available coating types with superior properties. Furthermore, novel methods introduced by Partner EEDM in order to determine the coating material properties, i.e. their coating stress strain curves (by means of FEM supported evaluation of the nanomeasurement results [1]), and their fatigue strength (by means of the impact test and its evaluation software [2,3]) offer more accurate facilities to perform the coating quality control. On the other hand, by means of a wide spectrum of cutting tests, both conventional and non-standard ones with simple and complicated kinematics, it is possible to find out the cutting performance of thin hard coatings [4,5,6,7,8,9,10]. In the framework of this project, the aforementioned scientific background will be used to characterize the cutting performance of advanced coatings, deposited on milling and turning cutting tools. These coatings will be produced in a new PVD installation of ISCAR, and will be tested both by ISCAR and EEDM regarding their cutting performance in order to check the coating process effectiveness of this installation. The experience gained from EEDM working in this research field through the last ten years, will be adopted to facilitate the evaluation of the PVD installation, which has to be finally adjusted according to the real cutting tool requirements of ISCAR. Moreover, CEMECON will develop new PVD coatings specially designed for ISCAR's needs. The investigation of the fatigue and wear resistance of these coatings, as well as the determination of their mechanical properties will be carried out by EEDM. The results of these investigations will be of major importance in terms of an optimization of the novel coatings and a fine adaptation of their mechanical properties to ISCAR's application requirements. Analytically, the scientific approach being established by EEDM comprises a Finite Elements Method (FEM) continuous simulation of nanoindentation hardness tests, in order to extract the coating stress strain curves [1,11]. In addition, coating impact tests are applied, in terms of a convenient experimental method, to find out the fatigue strength of hard coatings exposed in alternate impact loads [2,3,12]. The contact load that leads to coating fatigue fracture is recorded in fatigue like diagrams versus the corresponding number of impacts. Herewith Smith and Woehler diagrams can be established for each examined coating. The initiation and progress of the tool failure is examined through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray microspectral investigations of the used cutting edges. The application of 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 fatigue failure. Hereby critical coating fatigue stresses determined by means of the impact test are considered. Affecting parameters, such as the tool cutting wedge radius, the rake pre- and post-treatment, the feedrate, the cutting speed, the coating material itself etc, are also considered in order to optimize the fatigue strength as well as the overall cutting performance. References: 1. Bouzakis, K.-D., Michailidis, N., Erkens, G., 'Thin hard coatings stress-strain curves determination through a FEM supported evaluation of nanoindentation test results and herewith interpretation of coating fracture behaviour during the impact test', Accepted for oral presentation in Plasma Surface Engineering (PSE) 2000 Conference September 17-21 Garmisch-Partenkirchen, (2000). 2. Bouzakis, K.-D., Vidakis, N., David, K., 'The concept of an advanced impact tester supported by evaluation software in characterization of hard layered media', Thin Solid Films, vol. 355/356, (1999), pp: 322-329. 3. O. Knotek, K. D. Bouzakis, K. David, A. Siganos, A. Lontos, N. Michailidis, T. Leyendecker, G. Erkens, 'Control of adhesion and structure of PVD wear-resistant coatings by an improved impact tester', Plasma Surface Engineering (PSE) 2000 Conference September 17-21 Garmisch- Partenkirchen, (2000) 4. K. D. Bouzakis, N. Michailidis, N. Vidakis, K. Efstathiou, T. Leyendecker, G. Erkens, R. Wenke, H.-G. Fuss, 'Optimization of the cutting edge radius of PVD- coated inserts in milling considering film fatigue failure mechanisms', in press in Surface and Coatings Technology, (2000). 5. Bouzakis, K.-D., Vidakis, N., Michailidis, N., Leyendecker, T., Erkens, G., Fuss, G., 'Quantification of properties modification and cutting performance of (TixAl1-x)N coatings at elevated temperatures', Surface and Coating Technologies, vol. 120/121, (1999), pp: 34-43. 6. K.-D. Bouzakis, N. Michailidis, N. Vidakis, K. Efstathiou, S. Kompogiannis, G. Erkens, Interpretation of PVD coated inserts wear phenomena in turning, Annals of the CIRP Vol. 49/1/2000 (2000), pp: 65-68. 7. K.-D. Bouzakis, N. Michailidis, N. Vidakis, K. Efstathiou, Failure mechanisms of physically vapour deposited coated hardmetal cutting inserts in turning, in press in WEAR, (2000) 8. K.-D. Bouzakis, G. Koutoupas, A. Siganos, T. Leyendecker, G. Erkens, A. Papapanagiotou, P. Nikolakakis, Increasing of cutting performance of PVD-coated cemented carbide inserts in chipboard milling through improvement of the film adhesion, considering the coating cutting loads, in press in Surface and Coatings Technology, (2000). 9. Bouzakis, K.-D., Vidakis, N., Kallinikidis, D., Leyendecker, T., Lemmer, O., Fuss, H.G., Erkens, G., 'Fatigue failure mechanisms of multi- and mono-layer physically vapour deposited coatings in interrupted cutting processes', Surface and Coatings Technology, vol.108/109, (1998), pp: 526-534. 10. Bouzakis, K.-D., Kompogiannis, S., Antoniadis, M., Vidakis, N., Modeling of Gear Hobbing. Cutting Simulation, Tool Wear Prediction Models and Computer-Supported Experimental-Analytical Determination of the Hob Life-Time, Best paper Award in ASME International Mechanical Engineering Congress and Exposition, In press in ASME journal of Manufacturing Technology, 1999. 11. Bouzakis K.-D., Michailidis N., Erkens G.: FEM Supported of Nanoidentation Test Results and herewith Thin Hard Coatings Stress-Strain Curves Determination. MTC 2000 Conference, 8-9 November 2000, Jerusalem, ISRAEL. 12. Bouzakis K.-D., Vidakis N., Leyendecker T., Lemmer O., Fuss H.G., Erkens G.: Determination of the fatigue behaviour of thin hard coatings using the impact test and a FEM simulation. Surface and Coatings Technology 86-87 (1996), 549-556. Keywords: coatings, cutting tools, gears.
Acronym: 
ACTOOLS
Project ID: 
2 520
Start date: 
01-01-2001
Project Duration: 
18months
Project costs: 
250 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.