Influence of tribological conditions on application relevant component properties of cold forged gears

  • A. RohrmoserEmail author
  • C. Kiener
  • H. Hagenah
  • M. Merklein
Original Paper


In recent years there have been increasing attempts to enable the production of net-shape gears by forming methods. Cold forging enables improved material and energy efficiency compared to conventional gear manufacturing processes. In the extrusion process, a high surface quality, an increased hardness of the tooth profile as well as a load adapted fibre orientation is achieved. The procedure thus offers the potential to manufacture net-shape gears in a process suitable for series production. Due to the high tribological loads resulting from pronounced deformation and surface enlargement, the tribological conditions substantially influence the process result and the application relevant component properties. The tribological conditions are mainly affected by the applied lubrication system. The aim of this contribution is to investigate the influence of tribological conditions on the resulting component properties of cold forged steel gears. For this purpose different lubrication systems with and without a phosphate conversion layer are applied and the resulting component properties are determined. Phosphate-free lubrication systems offer substantial potential, especially from an ecological point of view. However, the high tribological loads during gear manufacturing pose a challenge. Based on the determined change of the tribological conditions and the resulting component properties, functional correlations are identified. The results show that friction has a distinct influence on the die filling and the application-relevant component properties.


Cold forging Gears Lubrication 



The authors thank the German Research Foundation (DFG) for supporting the research project “FOR 2271 process-oriented tolerance management based on virtual computer-aided engineering tools” under Grant number ME 2043/55-1.


  1. 1.
    Niemann G, Winter H (1980) Machine elements: design and calculation in mechanical engineering, vol 2. Springer, HeidelbergGoogle Scholar
  2. 2.
    Schöck J, Kammerer M (1999) Verzahnungsherstellung durch Kaltfließpressen. Umformtechnik 4:36–42Google Scholar
  3. 3.
    Gupta K, Laubscher R, Davim JP, Jain N (2016) Recent developments in sustainable manufacturing of gears: a review. J Clean Prod 112:3320–3330CrossRefGoogle Scholar
  4. 4.
    Jeong MS, Lee SK, Yun JH, Sung JH, Kim DH, Lee S, Choi TH (2013) Green manufacturing process for helical pinion gear using cold extrusion process. Int J Precis Eng Manuf 14(6):1007–1011CrossRefGoogle Scholar
  5. 5.
    Lange K, Dohmen H (2013) Präzisionsumformtechnik: Ergebnisse des Schwerpunktes „Präzisionsumformtechnik “der Deutschen Forschungsgemeinschaft 1981 bis 1989. Springer, BerlinGoogle Scholar
  6. 6.
    Buschhausen A, Weinmann K, Lee JY, Altan T (1992) Evaluation of lubrication and friction in cold forging using a double backward-extrusion process. J Mater Process Technol 33(1–2):95–108CrossRefGoogle Scholar
  7. 7.
    Rohrmoser A, Heling B, Schleich B, Kiener C, Hagenah H, Wartzack S, Merklein M (2019) A methodology for the application of virtual evaluation methods within the design process of cold forged steel pinions. In: Proceedings of the 22th international conference on engineering design ICED 2019 acceptedGoogle Scholar
  8. 8.
    VDI-Standard (1986) Prestressed dies for cold forging. VDI 3176. Beuth, BerlinGoogle Scholar
  9. 9.
    Behrens BA, Odening D (2009) Process and tool design for precision forging of geared components. Int J Mater Form 2(S1):125–128CrossRefGoogle Scholar
  10. 10.
    Hockett J, Sherby O (1975) Large strain deformation of polycrystalline metals at low homologous temperatures. J Mech Phys Solids 23(2):87–98CrossRefGoogle Scholar
  11. 11.
    Neale M (1995) The tribology handbook. Butterworth-Heinemann, OxfordGoogle Scholar
  12. 12.
    Bay N (1994) The state of the art in cold forging lubrication. J Mater Process Technol 46(1–2):19–40CrossRefGoogle Scholar
  13. 13.
    Tamilselvi M, Kamaraj P, Arthanareeswari M, Devikala S, Selvi JA (2015) Progress in zinc phosphate conversion coatings: a review. Int J Adv Chem Sci Appl 3(1):24–41Google Scholar
  14. 14.
    Donofrio J (2010) Zinc phosphating. Metal Finish 108(11–12):40–56CrossRefGoogle Scholar
  15. 15.
    Ludwig H, Zang S, Oehler O, Holz J, Venzlaff H, Ostrowski J (2016) Umweltfreundliche Prozessketten in der Kaltmassivumformung von Abschnitten durch den Verzicht auf nasschemisch aufgebrachte Konversionsschichten. Abschlussbericht “Phosphatfreie Kaltmassivumformung”. Deutsche Bundesstiftung Umwelt, OsnabrückGoogle Scholar
  16. 16.
    Nittel K, Bucci B, Hellwig R, Schoppe J, Ostrowski J, Zwez P, Zwez R, Stahlmann J, Groche P (2010) Surface treatment—facts, trends and outlook for the cold forging industry. In: Proceedings of ICFG plenary meeting. pp 142–152Google Scholar
  17. 17.
    Stachowiak G, Batchelor AW (2005) Engineering tribology, 3rd edn. Elsevier Butterworth-Heinemann, BostonGoogle Scholar
  18. 18.
    Bay N (2013) New tribo-systems for cold forming of steel, stainless steel and aluminium alloys. Paper presented at the 46th International Cold Forging Group (ICFG) Plenary MeetingGoogle Scholar
  19. 19.
    Lorenz R, Hagenah H, Merklein M (2017) Experimental evaluation of cold forging lubricants using double-cup-extrusion-tests. Mater Sci Forum 918:65–70CrossRefGoogle Scholar
  20. 20.
    ISO-Norm (2013) Cylindrical gears—ISO Systems of accuracy—part 1: definitions and allowable values of deviations relevant to corresponding flanks of gear teeth ISO 1328-1. Beuth, BerlinGoogle Scholar
  21. 21.
    Dudley DW (2013) Dudley’s handbook of practical gear design and manufacture. Springer, BerlinGoogle Scholar
  22. 22.
    Johnney Mertens A, Kumar P, Senthilvelan S (2016) The effect of the mating gear surface over the durability of injection-molded polypropylene spur gears. Proc Inst Mech Eng Part J J Eng Tribol 230(12):1401–1414CrossRefGoogle Scholar
  23. 23.
    VDI-Standard (2015) Measurement and testing of gearings—surface roughness measurement of cylindrical gears and bevel gears by means of stylus-type instruments. VDI 2612-5. Beuth, BerlinGoogle Scholar
  24. 24.
    Bausch T (2015) Innovative Zahnradfertigung: Verfahren, Maschinen und Werkzeuge zur kostengünstigen Herstellung von Stirnrädern mit hoher Qualität; mit 64 Tabellen. 5., neu bearb. und aktualisierte Aufl. edn. expert-Verlag, RenningenGoogle Scholar
  25. 25.
    ICFG-Document (2002) Tool life and tool quality in cold forging. General aspects of tool life. Part One. Meisenbach Verlag, BambergGoogle Scholar
  26. 26.
    Groche P, Kramer P, Bay N, Christiansen P, Dubar L, Hayakawa K, Hu C, Kitamura K, Moreau P (2018) Friction coefficients in cold forging: a global perspective. CIRP Ann 67(1):261–264CrossRefGoogle Scholar
  27. 27.
    Groche P, Heß B (2014) Friction control for accurate cold forged parts. CIRP Ann 63(1):285–288CrossRefGoogle Scholar
  28. 28.
    Missal N, Liewald M, Felde A (2016) A piston pin optimisation with respect to lightweight design. In: 49th plenary meeting, international cold forging group, StuttgartGoogle Scholar
  29. 29.
    Groche P, Kramer P, Zang S, Rezanov V (2015) Prediction of the evolution of the surface roughness in dependence of the lubrication system for cold forming processes. Tribol Lett 59(1):9CrossRefGoogle Scholar

Copyright information

© German Academic Society for Production Engineering (WGP) 2019

Authors and Affiliations

  1. 1.Department Mechanical Engineering, Institute of Manufacturing TechnologyFriedrich-Alexander-Universität Erlangen-Nürnberg (FAU)ErlangenGermany

Personalised recommendations