Bernhard Karpuschewski

Leibniz-Institut für Werkstofforientierte Technologien - IWT

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Oltmann Riemer

University of Bremen

Jens Sölter

Leibniz-Institut für Werkstofforientierte Technologien - IWT

M. Beutner

Otto-von-Guericke University Magdeburg

János Kundrák

University of Miskolc

Jonas Heinzel

University of Bremen

Florian Welzel

Gesellschaft für Fertigungstechnik und Entwicklung

Dmytro Borysenko

Leibniz-Institut für Werkstofforientierte Technologien - IWT

A.M. Hoogstrate

Netherlands Organisation for Applied Scientific Research

Hans Kurt Tönshoff

Leibniz University Hannover

JÉ

Jérémy Épp

Leibniz-Institut für Werkstofforientierte Technologien - IWT

Cooperative Institutions

Otto-von-Guericke University Magdeburg

University of Bremen

Leibniz-Institut für Werkstofforientierte Technologien - IWT

Walter de Gruyter (Germany)

Staats- und Universitätsbibliothek Bremen

Leibniz University Hannover

Fraunhofer Institute for Machine Tools and Forming Technology

University Hospital Magdeburg

RWTH Aachen University

Chemnitz University of Technology

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Sensors for Workpieces: Sensors for Physical Properties

Bernhard Karpuschewski

This chapter contains sections titled: Introduction Laboratory reference techniques Sensors for process quantities Force sensors Power sensors Temperature sensors Acoustic emission sensors Sensors for tools Sensors for workpieces Eddy-current sensors Micro-magnetic sensors References

10.1002/9783527619252.ch3c

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Citations (0)

Minimum Quantity Lubrication (MQL) multiphase dynamics of a vibration-assisted drilling process

Procedia CIRP (2023)

Lizoel Buss Lukas Schumski Jens Sölter Kerstin Avila Bernhard Karpuschewski

Metalworking fluid (MWF) consumption in machining processes can be minimised using minimum quantity lubrication (MQL). In the vibration-assisted drilling process, the MWF is transported as aerosol (dispersed droplets in gas) to the cutting zone through microchannels inside the drilling tool. Numerical simulations have been applied to elucidate the multiphase flow dynamics of the MWF inside a helical microchannel of a twist drilling tool. Numerical results indicate a transition from the inserted MQL aerosol flow and a wall film already after the first helical bend of the microchannel. The wall film contains > 90 % of the lubricant and is strongly localised on only 10 % of the microchannel circumference at the tool tip. This MQL-flow behaviour has to be considered in future investigations of the processes at the borehole ground, where even more complex phenomena occur.

Microchannel

Multiphase flow

Cutting fluid

10.1016/j.procir.2023.03.071

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Citations (7)

An Investigation on Internal Material Loads and Modifications in Precision Turning of Steel 42CrMo4

Micromachines (2021)

Tjarden Zielinski Andrey Vovk Oltmann Riemer Bernhard Karpuschewski

The functional properties of a workpiece are determined by a modification of the surface and subsurface materials. In this work, the correlation between thermo-mechanical material loads and the modification of the residual stresses is presented. While the resulting residual stresses were measured by X-ray diffraction after machining experiments, the material loads were determined using a process simulation. The experimental data (measured process forces and results from previous experiments) are used to validate the simulation, which is then applied to calculate the internal thermo-mechanical loads of the maximal temperature and the equivalent von-Mises-stresses per volume element during the machining experiments. In conclusion, a higher depth impact of mechanical loads compared to a lower depth impact of thermal loads in precision machining is observed. For the sake of novelty, the thermo-mechanical loads were plotted and interpreted in a three-dimensional fashion. Finally, cross sections of this mutual representation at certain constant material loads—thermal and mechanical—result in a process signature, which can prospectively improve the prediction of functional workpiece properties.

Mechanical load

Surface Integrity

10.3390/mi12050526

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Citations (7)

Flow Visualisation and Evaluation Studies on Metalworking Fluid Applications in Manufacturing Processes—Methods and Results

Processes (2023)

Udo Fritsching Lizoel Buss Teresa Tonn Lukas Schumski Jurgen Gakovi

Metalworking operations rely on the successful application of metalworking fluids (MWFs) for effective and efficient operation. Processes such as grinding or drilling often require the use of MWFs for cooling, lubrication, and chip removal. Electrochemical machining processes require electrolyte flow to operate. However, in those machining operations, a fundamental understanding of the mode of action of MWF is lacking due to the unknown flow dynamics and its interaction with the material removal during the process. Important information on the behaviour of MWFs during machining can be obtained from specific experimental flow visualisation studies. In this paper, promising flow visualisation analysis techniques applied to exemplary machining processes (grinding, sawing, drilling, and electrochemical machining) are presented and discussed. Shadowgraph imaging and flow measurements, e.g., particle image velocimetry, allow the identification of typical flow and MWF operating regimes in the different machining processes. Based on the identification of these regimes, efficient machining parameters and MWF applications can be derived. In addition, detailed experimental analyses of MWFs provide essential data for the input and validation of model development and numerical simulations within the Priority Programme SPP 2231 FluSimPro.

Metal working

Electrochemical Machining

10.3390/pr11092690

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Citations (2)

Influence of local material loads on surface topography while machining steel 42CrMo4 and Inconel 718

Procedia CIRP (2022)

Tjarden Zielinski Andrey Vovk Oltmann Riemer Bernhard Karpuschewski

The resulting topography after machining and its dependence of newly determined local material loads were investigated. An experimental study was carried out for not only steel 42CrMo4, but also Inconel 718 to prove the transferability of process signatures to other materials with a significantly different machinability characteristic. For the evaluation of the surface integrity, the surface topography was measured and the generated subsurface zone was characterized by metallographic analysis of the processed samples. In addition the local material loads of temperature and von-Mises-stresses were determined by FEM using the software ABAQUS with a coupled Euler-Lagrange (CEL) process simulation.

Inconel

Machinability

Surface Integrity

Transferability

10.1016/j.procir.2022.03.064

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Citations (2)

Digital surface twin for ultra-precision high performance cutting

Precision Engineering (2022)

Lars Schönemann Oltmann Riemer Bernhard Karpuschewski Per Schreiber Heinrich Klemme

10.1016/j.precisioneng.2022.06.010

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Citations (8)

Inline-deep rolling – a new approach to increase tooth root load capacity

VDI Verlag eBooks (2019)

Bernhard Karpuschewski T. Lierse Stefan‐H. Schulze

Root (linguistics)

Tooth root

10.51202/9783181023556-1787

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Citations (2)

Surface Integrity Aspects of Milled Large Hardened Gears

Procedia CIRP (2014)

Bernhard Karpuschewski M. Toefke M. Beutner W. Spintig

With the rising performance of wind turbines the requirements for large scale gears are growing. Due to the bigger loads based on the higher megawatt output per turbine gears especially at slewing bearings need to be hardened. Rising demands for better gear qualities and higher loads require a hard machining of these hardened gears. The development of special cutting materials for geometrically well-defined cutting edge processes enables the manufactures to mill these gears in hardened condition on standard milling machines. The process of milling hardened gears needs control of the surface integrity of the tooth flanks. The generation of white etching areas must be avoided and can be influenced by process parameters (e.g. cutting speed and feed rate). Preferably compressive residual stresses should be generated in the surface and sub-surface of the tooth flank. The paper describes the potentials of milling theses hardened gears instead of grinding and reveals the generated surface integrity state.

Surface Integrity

Hardened steel

Tooth surface

10.1016/j.procir.2014.04.007

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Citations (13)

Measuring procedures of cutting edge preparation when hard turning with coated ceramics tool inserts

Measurement (2014)

Bernhard Karpuschewski Konrad Schmidt Jozef Beňo Ildikó Maňková Julia Prilukova

Cutting tool

Scratch

10.1016/j.measurement.2014.06.008