Production Engineering

, Volume 5, Issue 5, pp 497–506

Reduction of wear at hot forging dies by using coating systems containing boron

  • Bernd-Arno Behrens
  • Günter Bräuer
  • Hanno Paschke
  • Marcus Bistron
Production Process

Abstract

The near surface area of forging dies is exposed to high mechanical loads. Additionally thermal and chemical stresses appear during the hot forging process. Depending on the number of forged parts, several kinds of stresses occur in the near surface area, which lead to the initial failures of forging dies. Wear is the main reason for production downtimes with a ratio of 70%. Furthermore, thermal and mechanical cracks are typical causes for failures causes as well as plastic deformation. In order to reduce wear, the abrasion resistance of the forging die surface has to be increased. Hence, different methods like plasma nitriding and optional additional thin hard coatings (TiN, TiCN, TiC, TiBN and TiB2) were successfully examined. Recently developed Ti–B–N coatings in specific multilayer designs are thermally stable, wear-resistant and anti-adhesive regarding the sticking of work piece material. This paper presents the wear reduction possibilities of boron-containing multilayer coating systems applied to forging dies by using the plasma enhanced chemical vapor deposition treatment. A basic mechanical and analytical characterization of different coating systems is realized in the first stage of the project. Best qualified multilayer coating variants were applied to forging dies for experimental investigations. As a result of the tests, wear can be reduced significantly by using thermally stable boron multilayer coatings. To receive realistic wear values under production conditions, an automated forging process was used for testing. After 3,000 forged parts, the coatings were examined by tactile measurement, SEM and EDX analyses to characterize the occurring wear.

Keywords

PACVD Coating design Multilayer Hot forging Wear resistance Cracks 

References

  1. 1.
    Bistron M, Behrens B-A, Paschke H (2010) Reduction of wear by boron based multilayer coatings on forging dies. Proceedings metal forming 2010, 13th international conference, Steel Res Int 81/9:290–293Google Scholar
  2. 2.
    Behrens B-A, Bach Fr-W, Denkena B, Möhwald K, Deißer T, Kramer N, Bistron M (2009) Manufacturing of reinforced high precision forging dies. Steel Res Int 80:878–886Google Scholar
  3. 3.
    Bistron M, Behrens B-A, Bach Fr-W, Möhwald K, Deißer T (2010) Reduction of wear by using boron containing thin coatings at forging of helical gears. Proceedings of the 16th international symposium on plasticity: “finite plasticity and visco-plasticity of conventional and emerging materials”:187–189Google Scholar
  4. 4.
    Karvankova P, Veprek-Heijman MGJ, Azinovic D, Veprek S (2006) Properties of superhard nc-TiN/a-BN and nc-TiN/a-BN/a-TiB2 nanocomposite coatings prepared by pacvd. Surf Coat Technol 200:2978–2989. doi:10.1016/j.surfcoat.2005.01.003 CrossRefGoogle Scholar
  5. 5.
    Mayrhofer P-H, Stoiber M (2007) Thermal stability of superhard Ti–B–N coatings. Surf Coat Technol 201:6148–6153CrossRefGoogle Scholar
  6. 6.
    Mitterer C, Mayrhofer PH, Musil J (2003) Thermal stability of PVD hard coatings. Vacuum 71:279–284CrossRefGoogle Scholar
  7. 7.
    Veprek S, Nesladek P, Niederhofer A, Glatz F (1998) The search for novel, superhard materials - nanocrystalline composites with hardness exceeding 50 GPa. Nanostruct Mater 10:679–689CrossRefGoogle Scholar
  8. 8.
    Chen L, Wang SQ, Du Y, Li J (2008) Microstructure and mechanical properties of gradient Ti(C, N) and TiN/Ti(C, N) multilayer PVD coatings. Mater Sci Eng 478:336–339CrossRefGoogle Scholar
  9. 9.
    Mitterer C, Holler F, Reitberger D, Badisch E, Stoiber M, Lugmair C, Noebauer R, Mueller T, Kullmer R (2003) Industrial applications of PACVD hardcoatings. Surf Coat Technol 163(164):716–722CrossRefGoogle Scholar
  10. 10.
    Stoiber M, Perlot S, Mitterer C, Beschliesser M, Lugmair C, Kullmer R (2004) PACVD TiN/Ti-B-N multilayers: from micro- to nano-scale. Surf Coat Technol 177(178):348–354CrossRefGoogle Scholar
  11. 11.
    López-Cartes C, Martínez-Martínez D, Sánchez-López JC, Fernández A, García-Luis A, Brizuela M, Oñate JI (2007) Characterization of nanostructured Ti-B-(N) coatings produced by direct current magnetron sputtering. Thin Solid Films 515:3590–3596CrossRefGoogle Scholar
  12. 12.
    Neidhardt J, Czigány Z, Sartory B, Tessadri R, O’Sullivan M, Mitterer C (2006) Nanocomposite Ti-B-N coatings synthesized by reactive arc evaporation. Acta Mater 54:4193–4200CrossRefGoogle Scholar
  13. 13.
    Kullmer R, Lugmair C, Figueras A, Bassas J, Stoiber M, Mitterer C (2003) Microstructure, mechanical and tribological properties of PACVD Ti(B, N) and TiB2 coatings. Surf Coat Technol 174–175:1229–1233CrossRefGoogle Scholar
  14. 14.
    Mitterer C, Mayrhofer P-H, Beschliesser M, Losbichler P, Warbichler P, Hofer F, Gibson PN, Gissler W, Hruby H, Musil J, Vlcek J (1999) Microstructure and properties of nanocomposite Ti-B-N and Ti-B-C coatings. Surf Coat Technol 120–121:405–411CrossRefGoogle Scholar

Copyright information

© German Academic Society for Production Engineering (WGP) 2011

Authors and Affiliations

  • Bernd-Arno Behrens
    • 1
  • Günter Bräuer
    • 2
  • Hanno Paschke
    • 2
  • Marcus Bistron
    • 1
  1. 1.Institute of Metal Forming and Metal-Forming Machines (IFUM)Leibniz Universität HannoverGarbsenGermany
  2. 2.Fraunhofer Institute for Surface Engineering and Thin Films (IST)DortmundGermany

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