Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK

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  • Publication
    Charakterisierung geometrisch bestimmter Schneiden
    ( 2011)
    Uhlmann, E.
    ;
    König, J.
    ;
    Dethlefs, A.
    ;
    Graf von der Schulenburg, M.
    Schneidkanten an Hartmetall-Wendeschneidplatten lassen sich durch Strömungsschleifen bearbeiten. Die Charakterisierung des Schneidkantenprofils mit den verfügbaren Modellen war bisher nicht eindeutig möglich. Dieser Fachbeitrag stellt ein neues Modell zur Charakterisierung von Schneidkantenprofilen vor, das eine eindeutige Beschreibung ermöglicht. Ausgehend von der neu eingeführten Schneidenprofilkennlinie (SPK) werden die Kennwerte "Radiuskontinuität" (RK) sowie "Eingriffsquotient" (EQ) definiert.
  • Publication
    Investigations on the adjustment of the modelling section in 2D simulations of milling processes
    ( 2009)
    Uhlmann, E.
    ;
    Mattes, A.
    ;
    Graf von der Schulenburg, M.
    ;
    Gerstenberger, R.
    Conducting 3D simulation of milling processes still causes high efforts. There, only small workpiece sections can be modelled so far, instead of the entire contact width. Approaches using 2D simulation pose an interesting alternative. Here, the two-dimensional perspective is gained by dividing the workpiece into different sections perpendicular to the feed rate. This, however, requires a modelling approach that covers arbitrary contact widths along with a high mesh density in the area of chip formation. Automatically adjusting the modelling section hereby helps to model contact width up to 180° by segmentally simulating the rotation of the milling cutter. This paper presents the investigations on the effect of the most important parameters which influence sufficiently accurate computation of the equivalent cutting forces as in conventional 2D simulation models using the software DEFORM 2D.
  • Publication
    Gezieltes Schneidkantenverrunden mit Diamantschleifmedien
    ( 2008)
    Graf von der Schulenburg, M.
    ;
    Mihotovic, V.
    ;
    Uhlmann, E.
  • Publication
    Entwicklung leistungsfähiger Zerspanungstechnologien
    ( 2008)
    Uhlmann, E.
    ;
    Byrne, F.
    ;
    Oyanedel-Fuentes, J.A.
    ;
    Gerstenberger, R.
    ;
    Graf von der Schulenburg, M.
    ;
    König, J.
    ;
    Mattes, A.
    ;
    Richarz, S.
    ;
    Roeder, M.
    Der Beitrag stellt Aktivitätsfelder im Bereich der Zerspanungstechnik an einem von der Fraunhofer-Gesellschaft und der TU Berlin gemeinsam betriebenen Entwicklungszentrum vor. Kapitelüberschriften: neue Entwicklungen zur Zerspanung gehärteter Stähle; geometrische Modifikation von Diamant-Schneideinsätzen mit Laserstrahlen; Entwicklung und Einsatz superdünner Dünnschichtsysteme im Zerspanungswerkzeugen; Analyse der Zerspanbarkeit von partikelverstärkten Titanlegierungen; Modellierung von Größeneffekten bei der Zerspanung von Verbundwerkstoffen. Die Ausführungen werden durch Fotos von Anlagen und mikroskpischen Strukturen sowie durch tabellarische Ergebnisse ergänzt. Entnommen aus TEMA
  • Publication
    Innovative Zerspantechnologien für die Optimierung von Produktionsprozessen
    ( 2007)
    Uhlmann, E.
    ;
    König, J.
    ;
    Mattes, A.
    ;
    Richarz, S.
    ;
    Roeder, M.
    ;
    Graf von der Schulenburg, M.
  • Publication
  • Publication
    Scaling of the milling process of tungsten-copper-composites
    ( 2007)
    Uhlmann, E.
    ;
    Graf von der Schulenburg, M.
    This article deals with the experimental and numerical research of scaling effects occurring in the milling process of tungsten-copper-composites (WCu). The experimental tests served to quantify single scaling effects like e.g. milling cutter diameter and the feed per tooth. To enhance the understanding of the process the effects were emulated numerically with finite element simulations. In all experiments an intense impact of the specific WCu material properties on the machining process and the quality of the process output was detectable. The tests concerning the tool displacement showed that an enlargement of the feed per tooth causes a significant increase of the tool displacement and also that a smaller mass fraction of tungsten promotes a smaller tool displacement, however at the cost of higher data scattering. A high tungsten mass fraction impedes the chip formation and leads to intense tool deformations due to the hardness of tungsten. The preliminary quasistatic chipping tests validated that a lower tungsten mass fraction leads to decreasing cutting forces. The increasing cutting forces coming along with smaller tungsten particle size correlated with milling experiment executed previously but were only detected with WCu 60/40 so far. The SEM pictures show clear differences between the WCu specifications and support the high impact of the WCu material characteristics. A thermographic test setup was developed to obtain knowledge about the temperatures at the tip of the cutting edge of a milling tool. The tests pointed out that the temperature rises during the engagement time whereas most of the cooling happens in the first quarter of the idle time. Since the previous 3D model used for FEM simulations did not provide a constant element size in the model for different WCu specifications a new fully parameterized geometry preprocessor was programmed. First simulations confirmed the strong influence of the WCu specifications on the process outcome. Entnommen aus TEMA
  • Publication
    Investigations on the adjustment of the modeling section in 2D simulation of milling processes
    ( 2007)
    Uhlmann, E.
    ;
    Mattes, A.
    ;
    Zettier, R.
    ;
    Graf von der Schulenburg, M.
    Conducting 3D simulation of milling processes still causes high efforts. There, only small workpiece sections can be modeled so far, instead of the entire contact width. Approaches using 2D simulation pose an interesting alternative. Here, the two-dimensional perspective is gained by dividing the workpiece into different sections perpendicular to the feed rate. This, however, requires a modeling approach that covers arbitrary contact widths along with a high mesh density in the area of chip formation. Automatically adjusting the modeling section hereby helps to model contact width up to 180 deg by segmentally simulating the rotation of the milling cutter. The paper presents the investigations on the effect of the most important parameters which influence sufficiently accurate computation of the equivalent cutting forces as in conventional 2D simulation models using the software DEFORM 2D. The operational reliability of the model was verified by a newly conducted simulation conducted using the new simulation model, with which the points in time of the adjustments for a model section were not recognizable at the cutting force distribution. In addition a realistic cutting force plot for milling operation was realised and the stress occurring at the end of a workpiece section could be held on a constant level. Undesired variations compared to simulations without adjustment of the modelling sections were limited on an area behind the tip of the cutting wedge. There, risings in stress occur inside the workpiece after modifications of the model. An influence on the cutting force however was not observable. Thus, the new simulation model accomplishes the requirements for the simulation of long cutting distances at reduced computing time. However, further studies will have to show, how applicable these results are for other simulation parameters. Entnommen aus TEMA
  • Publication
    2D und 3D FEM-Simulationen an Wolfram-Kupfer-Verbundwerkstoffen
    ( 2007)
    Uhlmann, E.
    ;
    Graf von der Schulenburg, M.