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作者： Neugebauer, R. Mueller, B. Wagner, A. Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

ISBN: (纸本)9780415873079

Selective Laser Melting technologies have given a new boost to Rapid Tooling applications of Layer-Based Technologies, especially in plastic injection molding for prototype and pre-series tooling, but also for Conformal Cooling in production moulds. So far only very few and basic applications have become known for forming tooling like sheet metal forming, stamping or die forging. Market demands for "real forgings in a one week time" have lead to a case study with the goal to successfully produce forgings using a layer manufactured die. This paper presents this case study and its first results, compared to conventional tooling. Derived from the experimental work this paper gives a prospective on expedient future applications of direct Rapid Tooling for die forging, using Laser Melting technologies. © 2010 Taylor & Francis Group.

关键词： Melting

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Approaches to enhance surface integrity in turning of aluminium matrix composites 10

Approaches to enhance surface integrity in turning of alumin...

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10th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2010

作者： Schubert, A. Nestler, A. Department in Micromanufacturing Technology Chemnitz University of Technology Germany Fraunhofer Institute for Machine Tools and Forming Technology Germany

ISBN: (纸本)9780955308284

Aluminium matrix composites are innovative lightweight construction materials, which usually consist of a relatively soft and ductile matrix and a hard ceramic reinforcing component. The high hardness of the reinforcing component results in extensively increased cutting tool wear by abrasion as well as defects of the machined surface in the form of voids and scaling. In this study, turning tests were conducted on Al2O3 particle-reinforced aluminium to evaluate the effect of tool edge geometry on cutting performance and surface integrity. These investigations have shown a significant reduction of the roughness and surface defects using tools with appropriate rake geometries. © euspen Headquarters.

关键词： Surface defects

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Model-based self-optimization for manufacturing systems

Model-based self-optimization for manufacturing systems

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International Conference on Concurrent Enterprising

作者： Ulrich Thombansen Jens Schuttler Thomas Auerbach Marion Beckers Guido Buchholz Urs Eppelt Yves-Simon Gloy Peter Fritz Stephan Kratz Juliane Lose Thomas Molitor Axel ReßBmann Andreas Schreiber Dražen Veselovac Konrad Willms Thomas Gries Walter Michaeli Dirk Petring Reinhard Poprawe Uwe Reisgen Robert Schmitt Wolfgang Schulz Fritz Klocke Fraunhofer Institute for Laser Technology (ILT) Aachen Germany Fraunhofer Institute for Laser Technology (ILT) Germany Laboratory for Machine Tools and Production Engineering of RWTH Aachen University Chair of Manufacturing Technology (WZL-TF) Germany Institute for Welding and Joining (ISF) at RWTH Aachen University Germany RWTH Aachen University Chair for Nonlinear Dynamics of Laser Processing (NLD) Germany Institut für Textiltechnik (ITA) der RWTH Aachen Germany Laboratory for Machine Tools and Production Engineering of RWTH Aachen University Chair of Metrology and Quality Management (WZL-MQ) Germany Institute of Plastics Processing (IKV) at RWTH Aachen University Germany

This paper describes an approach to self-optimization for manufacturing systems that addresses the plan - value orientation of the polylemma of production for high wage countries. The scope of the work comprises research on cognition for technical systems as well as transfer of process knowledge into machine readable form oriented towards product quality. Based on a meta-model approach, specialized processing of data from several information sources allows determination of the operating point and optimization potential considering the operating domain. Consequently, information-processing sensor actuator systems are implemented that adapt to optimized internal objectives and the current process status to ensure meeting of predefined external objectives.

关键词： Computational modeling Process control Manufacturing processes Actuators Current measurement Measurement by laser beam

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3D-characterization method and morphological filtering for the assessment and the design of friction optimized surfaces

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Journal of Physics: Conference Series 2011年第1期311卷

作者： S Gröger T Burkhardt M Dietzsch Chemnitz University of Technology Institute of Production Measuring Technology and Quality Assurance Reichenhainer Str. 70 09126 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

For a specific manipulation of friction surfaces it is important to measure and calculate geometrical parameters to derive the tribological behavior. The new functional approach presented in this paper is the calculation of the characteristic lateral extension of the real contact surface as well as the representative contact radius by applying morphological filters to a 3D-set of data. All surface characteristics, including form, waviness, roughness as well as defined microstructures, are extracted holistically with a 3D Coordinate Measuring Instrument or a Form Measuring Instrument, but with the smallest available tip radius. The paper presents the benefit of this holistic extraction method and the application of morphological filtering for the description of the contact form (plateau or sphere), the real contact surface, number of contacts, the typical contact radius and the typical lateral extension of the micro contact plateaus.

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Micro impact extrusion of precision cavities with modular dies 10

Micro impact extrusion of precision cavities with modular di...

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10th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2010

作者： Schubert, A. Pohl, R. Hackert, M. Department Micromanufacturing Technology Faculty of Mechanical Engineering Chemnitz University of Technology Chemnitz09107 Germany Fraunhofer Institute for Machine Tools and Forming Technology Chemnitz09126 Germany

ISBN: (纸本)9780955308284

Micro impact extrusion is investigated at Chemnitz University of technology as a potential procedure for large area machining of micro cavities within the scope of the Collaborative Research Centre SFB/Transregio 39 PT-PIESA of the German Research Foundation. Applying impact extrusion, micro forming is done by material flow opposite to the effective direction of the force exerted by the tool. Therefore, no structured die plates are necessary, but high forming forces are required. In this study the influence of process parameters is investigated. © euspen Headquarters.

关键词： Extrusion

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Novel measurement and monitoring system for forming processes based on piezoresistive thin film systems

Novel measurement and monitoring system for forming processe...

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作者： Biehl, Saskia Staufenbiel, Sebastian Hauschild, Frank Albert, André Fraunhofer Institute for Surface Engineering and Thin Films Bienroder Weg 54 E Braunschweig 38108 Germany Fraunhofer Institute for Machine Tools and Forming Technology Reichenhainer Straße 88 Chemnitz 09126 Germany

The investigation of a novel sensor system, integrated in the main load region of forming machines, is the challenge. Therefore, it is important that the thin film system has an excellent tribological quality in combination with a piezoresistive behaviour. The layer system is deposited on the polished surface of a steel substrate. It has such geometries that it can be easily integrated in the drawing cushion of a deep drawing machine. The thin film sensor system exists out of a piezoresistive hydrogenated carbon layer. Onto this layer arrays of chromium structures are deposited. The structures are protected against wear by an insulating silicon doped hydrogenated carbon layer. The whole thin film system has a thickness of about 9 μm. During the forming process the steel plate is in direct touch with the sensor system and moves over it. The position of the steel is measured in dependence on the forming stadium. The sensor system works as a control system to ensure that the shape of the product is perfect and without any cracks or creases. © 2010 Springer-Verlag.

关键词： Thin films

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Chip length effect on the wear of coated cemented carbide inserts in milling

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Key Engineering Materials 2010年 438卷 49-56页

作者： Bouzakis, K.-D. Gerardis, S. Katirtzoglou, G. Makrimallakis, S. Skordaris, G. Efstathiou, K. Laboratory for Machine Tools and Manufacturing Engineering Aristoteles University of Thessaloniki Thessaloniki Greece Fraunhofer Project Center Coatings in Manufacturing Centre for Research and Technology Hellas Thessaloniki Greece Fraunhofer Institute for Production Technology Aachen Germany

ISBN: (纸本)0878492720

The effect of the developed chip length on the coated tool's cutting performance was investigated. Milling experiments at various cutting speeds and chip lengths were performed, which resulted to different tool wear developments. To explain these results, a FEM simulation of the cutting process was conducted and the related chip geometries were predicted and compared to the corresponding experimental ones. Based on these results, the Coulomb friction coefficient between chip and tool rake was appropriately adjusted to achieve a sufficient correlation between experimental and computational data. By additional FEM calculations, the mechanical and thermal loads of the cutting edge were estimated and insight was provided concerning the effect of chip length on coated tool stresses and film fatigue fracture. The obtained results revealed that the chip length reduction improves the cutting performance of coated tools and a significant increase of the removed material volume and material removal rate as well can be achieved. © (2010) Trans Tech Publications.

关键词： Milling (machining)

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Comparison of laser, laser-MIG and MIG welding for the manufacture of a magnesium automobile door made of tailored blanks as a demonstrator

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Welding and Cutting 2010年第6期9卷 378-384页

作者： Riedel, Frank Puschmann, Markus Fischer, Holger Department of Thermal Processing Fraunhofer Institute for Machine Tools and Forming Technology Chemnitz Germany

Wrought magnesium alloys continue to have a great lightweight construction potential for bodymaking in the automobile industry. Within the framework of the investigations of an innovative regional growth nucleus called TeMaK, comprehensive investigations were also conducted into the application potential of various ultramodern joining technologies. This article introduces results with regard to the laser welding, laser-MIG welding and MIG welding (metal inert gas welding) of magnesium sheets and the practical application for the manufacture of magnesium tailored blanks for the fabrication of a magnesium automobile door as a demonstrator.

关键词： Automotive industry

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Determination of the effective film mechanical properties in the impact test imprint of coated specimens

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Key Engineering Materials 2010年 438卷 131-138页

作者： Bouzakis, K.-D. Skordaris, G. Bouzakis, E. Lili, E. Laboratory for Machine Tools and Manufacturing Engineering Aristoteles University of Thessaloniki Thessaloniki Greece Fraunhofer Project Center Coatings in Manufacturing Centre for Research and Technology Hellas Thessaloniki Greece Fraunhofer Institute for Production Technology Aachen Germany

ISBN: (纸本)0878492720

If the film of a coated component deforms plastically because of operational loads, residual stresses are developed in the coating material after the load removal. In this way, material mechanical properties changes occur due to endogenous reasons i.e. induced by the coating crystalline structure plastic deformation. In this case, the determination of the effective film mechanical properties has been introduced in a recent publication [1]. Moreover, if the loading conditions lead only to a substrate plastic deformation, the coating remains elastically deformed during the relaxation, due to the substrate residual stresses. Thus, the associated material mechanical properties changes are caused by exogenous parameters related to the permanent substrate deformation. In the present paper, a novel experimental-analytical method based on FEM calculations is introduced to determine the effective film mechanical properties when the coating is stressed elastically due to a plastic substrate deformation. The perpendicular impact test is a convenient experimental procedure to investigate such an effect because under appropriate loading conditions, the substrate deforms plastically and the coating elastically. The pristine constitutive law of the applied PVD film was determined by nanoindentation and FEM supported results evaluation. Impact tests were conducted at various loads and loading cycles. The impact test was simulated by a two dimensional FEM model. Additionally, the developed elastic residual stress fields in the coating and the plastic ones of the substrate in the imprint were determined. In these calculations, a rate-independent anisotropic plasticity with kinematic hardening material law was considered and the film as an anisotropic material with variable mechanical properties in three main directions. Finally, by a FEM supported simulation of the nanoindention, the coating's load-displacement behaviour in various areas of the impact imprint were predicted and the e

关键词： Anisotropy

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New methods for characterizing coating properties at ambient and elevated temperatures

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Key Engineering Materials 2010年 438卷 107-114页

作者： Bouzakis, K.-D. Batsiolas, M. Malliaris, G. Pappa, M. Bouzakis, E. Skordaris, G. Laboratory for Machine Tools and Manufacturing Engineering Aristoteles University of Thessaloniki Thessaloniki Greece Fraunhofer Project Center Coatings in Manufacturing Centre for Research and Technology Hellas in Thessaloniki Greece Fraunhofer Institute for Production Technology in Aachen Germany

ISBN: (纸本)0878492720

In the paper, innovative methods for characterizing coatings' properties at ambient and elevated temperatures are introduced based on various experimental procedures. Nanoindentation results, which were obtained at elevated temperatures, are evaluated by FEM algorithms, rendering possible the determination of temperature dependent coating mechanical properties. Impact tests conducted on coated specimens revealed a non-linear film impact resistance versus the temperature. The latter results were evaluated by appropriate FEM supported procedures, to predict the coating fatigue endurance stress versus the temperature. In these investigations, the impact load was induced electromagnetically for a duration of ca. 1ms, depending on the force amplitude. To change the impact load characteristics, such as frequency, impact duration etc., a new test device has been developed, employing a piezoelectric actuator. This device enables the investigation of the impact time effect on the dynamic response of coated surfaces and on the coating fatigue endurance stress. Finally, diffusion phenomena in coatings were examined by a developed convenient experimental setup. A specimen is pressed onto a coated surface at adjustable high temperature and pressure in an inert atmosphere. After this test, the diffusion of characteristic elements into the coating and vice versa is detected by EDX-microanalyses. These results contribute, among others, to the description of diffusion phenomena between coatings and various materials. © (2010) Trans Tech Publications, Switzerland.

关键词： Diffusion

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