Lecture Notes in Production Engineering Berend Denkena · Adrian Rienäcker Gunter Knoll · Friedrich-Wilhelm Bach Hans Jürgen Maier · Eduard Reithmeier Editors Friedrich Dinkelacker Microstructuring of Thermo- Mechanically Highly Stressed Surfaces Final Report of the DFG Research Group 576 Lecture Notes in Production Engineering More information about this series at http://www.springer.com/series/10642 Berend Denkena • Adrian Rienäcker • Gunter Knoll Friedrich-Wilhelm Bach • Hans Jürgen Maier Eduard Reithmeier • Friedrich Dinkelacker Editors Microstructuring of Thermo-Mechanically Highly Stressed Surfaces Final Report of the DFG Research Group 576 Editors Berend Denkena Adrian Rienäcker Leibniz Universität Hannover Gunter Knoll Institut für Fertigungstechnik und Lehrstuhl für Maschinenelemente und Werkzeugmaschinen IFW Tribologie IMK Garbsen, Germany Universität Kassel Kassel, Germany Friedrich-Wilhelm Bach Hans Jürgen Maier Eduard Reithmeier Institut für Werkstoffkunde IW Institut für Mess- und Leibniz Universität Han nover RegelungstechnikIMR Garbsen, Germany Leibniz Universität Han nover Hannover, Germany Friedrich Dinkelacker Institut für Technische Verbrennung ITV Leibniz Universität Han nover Hannover, Germany ISSN2194-0525 ISSN2194-0533 (electronic) ISBN 978-3-319-09691-9 ISBN 978-3-319-09692-6 (eBook) DOI 10.1007/978-3-319-09692-6 Springer Cham Heidelberg New York Dordrecht London Library of Congress Control Number: 2014949153 © Springer International Publishing Switzerland 2015 This work is subject to copyright. 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Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Preamble V Preamble The fuel consumption of a modern combustion engine is one of the most important purchase criteria in contemporary society. Increasing oil prices and exhaust emis- sions taxes force the automotive industry to continuously improve the vehicle en- gines. The fuel consumption is closely related to the frictional losses of an engine. New material pairings or constructive modifications of the piston group can reduce such losses. Another innovative concept to lower the frictional forces is the micro- structuring of thermo-mechanically highly stressed surfaces. Within an interdiscipli- nary research group sponsored by the German Research Foundation, scientists at the Leibniz Universität Hannover and Universität Kassel have been working together to investigate this research topic. This final report presents their findings and offers scope for further discussion. On behalf of the DFG research group 576, Hannover, 1st of October, 2013 B. Denkena (spokesman of the DFG research group 576) Acknowledgement The presented investigations were undertaken with the support of the German Re- search Foundation within the scope of the (cid:179)(cid:48)(cid:76)(cid:70)(cid:85)(cid:82)(cid:86)(cid:87)(cid:85)(cid:88)(cid:70)(cid:87)(cid:88)(cid:85)(cid:76)(cid:81)(cid:74)(cid:3)(cid:82)(cid:73)(cid:3)(cid:55)(cid:75)(cid:72)(cid:85)(cid:80)(cid:82)-Mechanically (cid:43)(cid:76)(cid:74)(cid:75)(cid:79)(cid:92)(cid:3)(cid:54)(cid:87)(cid:85)(cid:72)(cid:86)(cid:86)(cid:72)(cid:71)(cid:3)(cid:54)(cid:88)(cid:85)(cid:73)(cid:68)(cid:70)(cid:72)(cid:86)(cid:180)(cid:3)research group (DFG Research Group 576). Contents VII Contents Formula symbols and abbreviations .................................................................... IX 1 Introduction ........................................................................................................... 1 2 Project overview ................................................................................................... 2 2.1 Consortium ................................................................................................... 2 2.2 Starting situation and need for action ........................................................... 4 2.3 Summary of main results ............................................................................. 7 3 Methods and models for the design of microstructures ........................................ 9 - G. Knoll, A. Rienäcker, S. Brandt, H. Fast 3.1 Objective and approach ............................................................................... 9 3.2 Comparison between Computational Fluid Dynamics and the Reynolds equation ....................................................................................................... 9 3.3 Investigation of dimple geometry and arrangement ................................... 11 3.4 Simulation model for piston ring friction coefficient test rig ......................... 18 3.5 Design and validation of a test engine simulation model ........................... 20 3.6 Conclusion ................................................................................................. 27 4 Microstructuring by means of cutting processes ................................................. 28 - B. Denkena, J. Kästner, T. Göttsching 4.1 Objective and approach ............................................................................. 28 4.2 Experimental set-up (cid:177) fly-cutting tests ....................................................... 29 4.3 High-quality cutting of micro-dimples ......................................................... 33 4.4 Inner structuring of rotationally symmetrical components .......................... 46 4.5 Conclusion ................................................................................................. 56 5 Microstructured thermally sprayed surfaces ....................................................... 58 - Fr.-W. Bach, K. Möhwald, M. Erne, C. Hübsch, H. J. Maier 5.1 Objective .................................................................................................... 58 5.2 Experimental .............................................................................................. 58 5.3 Outer coating of rotationally symmetric components ................................. 60 5.4 Inner coating of rotationally symmetric components .................................. 74 5.5 Tribological testing of the inner coating of cylinder liners ........................... 89 5.6 Conclusion ................................................................................................. 91 VIII Contents 6 Surface characterisation based on optical metrology .......................................... 93 - E. Reithmeier, M. Kästner, M. Bretschneider, O. Abo-Namous, F. Engelke 6.1 Objective and approach .............................................................................. 93 6.2 Measurement techniques ........................................................................... 94 6.3 Measurement of machined micro-dimples .................................................. 97 6.4 Measurement of thermal sprayed surfaces............................................... 109 6.5 Multi-measurement methods .................................................................... 111 6.6 Conclusion ................................................................................................ 116 7 Tribological mechanisms of microstructures ..................................................... 119 7.1 Tribological mechanisms of machined micro-dimples under planar contact conditions ................................................................................................... 119 - B. Denkena, J. Kästner, T. Göttsching 7.2 Tribological mechanisms of microstructured thermally sprayed surfaces ... 129 - Fr.-W. Bach, K. Möhwald, M. Erne, C. Hübsch, H. J. Maier 7.3 Tribological mechanisms of microstructured surfaces under dragged conditions ................................................................................................... 141 - G. Knoll, A. Rienäcker, S. Brandt, H. Fast 8 Test of cylinder liner under fired engine conditions ........................................... 146 - F. Dinkelacker, H. Ulmer 8.1 Objective and approach ............................................................................ 146 8.2 Engine test bench and cylinder liners ....................................................... 146 8.3 Methods to measure friction losses and oil emissions .............................. 149 8.4 Measurement uncertainty ......................................................................... 150 8.5 Validation of the measuring method ......................................................... 151 8.6 Results: frictional losses ........................................................................... 154 8.7 Results: oil emission ................................................................................. 162 8.8 Conclusion ................................................................................................ 164 9 Own publications ............................................................................................... 167 10 Quoted literature ............................................................................................... 170 Fo rmula symbols and abbreviations IX Formula symbols and abbreviations Formula Symbols Sign Unit Description (cid:168)a μm depth of cut deviation p A μm² cross section projection area A mm² cross-section of undeformed chip c A μm² longitudinal section projection area E A mm² micro-dimple area MT A μm² plane projection area p a μm depth of cut p a μm cut depth by circular fit p,fit A - threshold dimple depth p,hist a μm maximum depth of cut p,max A mm² total surface area tot. A 1 area of all pores divided by measured area V A Mm² cross section tool WZ b μm length of cross section / micro-dimple width b mm bore b μm width of ridges on side d(left, right) (histogram based) a,d(,hist) b mm cutting tool width WZ D mm component diameter D - damping matrix d(x,y) μm Euclidian metric D - number of dimples for a rectangular elemental surface MT f Hz natural frequency 0 F mm axial feed rate a,tool f - relative cut volume ab F μm polynomial surface fit of M accurate,interp 2,interp F μm polynomial surface fit of M accurate,zero 2,zero f mm axial feed rate ax