Experimental Investigation of Endogenous Lubrication during Cold Upsetting of Sintered Powder Metallurgical Components

Abstract:

Lubrication is essential in metal forming processes. As an example, it has a significant effect on the extent of homogeneity of forming and the resulting component surface. Thus, an adequate lubrication technique is required for a consistent part quality. In this contribution a new lubrication approach for cold bulk metal forming is presented. By exploiting the process-related porosity of powder metallurgical (PM) components as a lubricant storage, the resulting pressure of a forming process forces the stored oil to leak out lubricating the process. As a result, advantages like a decrease of process time because of the omission of the additional lubrication step, and an increased deformability due to compensation of lubricating film break are expected. Besides that, the porosity of the PM component is reduced leading to improved mechanical properties. Experimental investigations with cylindrical PM components were carried out by compression tests in dependence of initial porosity, impregnation time and lubricant. It was found that the required maximum load is reduced by up to 39 % by applying the new lubrication method. In addition, relative densities up to 99 % are reached after deformation.

• Periodical: Key Engineering Materials (Volume 767)
• Pages: 163-170
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.767.163
• Online since: April 2018
• Authors: Bernd-Arno Behrens, Kai Brunotte, Dieter Bohr*
• Keywords: Densification, Endogenous Lubrication, Powder metallurgy, Upsetting

References

[1] Behrens, B.-A., Bouguecha, A., Hadifi, T., and Mielke, J. 2011. Advanced friction modeling for bulk metal forming processes. Prod. Eng. Res. Devel. 5, 6, 621–627.

DOI: 10.1007/s11740-011-0344-8

[2] Yilkiran, T., Behrens, B.-A., Paschke, H., Weber, M., and Brand, H. 2012. The potential of plasma deposition techniques in the application field of forging processes. Archives of Civil and Mechanical Engineering 12, 3, 284–291.

DOI: 10.1016/j.acme.2012.06.002

[3] Behrens, B. A., Yilkiran, T., Braeuer, G., Paschke, H., and Weber, M. 2013. Potential of Duplex Plasma Deposition Processes for the Improvement of Wear Resistance of Hot Forging Dies. KEM 554-557, 345–358.

DOI: 10.4028/www.scientific.net/kem.554-557.345

[4] Behrens, B.-A., Bräuer, G., Paschke, H., and Bistron, M. 2011. Reduction of wear at hot forging dies by using coating systems containing boron. Prod. Eng. Res. Devel. 5, 5, 497–506.

DOI: 10.1007/s11740-011-0308-z

[5] Behrens, B.-A., Puppa, J., and Menze, J. 2014. Abkühlverhalten nitrierter und keramisch beschichteter Schmiedewerkzeuge. wt-online 104, 10, 686–690.

DOI: 10.37544/1436-4980-2014-10-686

[6] Behrens, B. A. and Puppa, J. 2015. Optimization of Cooling and Lubrication for Nitrided and Ceramic-Coated Hot Forging Dies. AMM 794, 97–104.

DOI: 10.4028/www.scientific.net/amm.794.97

[7] Bartz, W. J. op. 1993. Selbstschmierende und wartungsfreie Gleitlager. Typen, Eigenschaften, Einsatzgrenzen und Anwendungen. Kontakt & Studium Tribologie. expert-Verlag, Ehningen bei Böblingen.

[8] Hofmann, H. and Spindler, J. 2004. Verfahren der Oberflächentechnik. Grundlagen - Vorbehandlung - Beschichtung - Oberflächenreaktionen - Prüfung ; mit 72 Tabellen, zahlreichen Beispielen sowie einer CD-ROM. Fachbuchverl. Leipzig im Carl-Hanser-Verl., München.

[9] Bay, N. 1994. The state of the art in cold forging lubrication. Journal of Materials Processing Technology 46, 1-2, 19–40.

DOI: 10.1016/0924-0136(94)90100-7

[10] Gariety, M., Ngaile, G., and Altan, T. 2007. Evaluation of new cold forging lubricants without zinc phosphate precoat. International Journal of Machine Tools and Manufacture 47, 3-4, 673–681.

DOI: 10.1016/j.ijmachtools.2006.04.016

[11] Medea, F., Ghiotti, A., and Bruschi, S. 2016. Temperature Effects on Organic Lubricants in Cold Forging of AA1050 Alloy. Procedia Manufacturing 5, 308–318.

DOI: 10.1016/j.promfg.2016.08.027

[12] Lenel, F. V. 1980. Powder metallurgy. Principles and applications. Metal Powder Industries Federation, Princeton, N.J.

[13] Schatt, W., Wieters, K.-P., and Kieback, B. 2007. Pulvermetallurgie. Technologien und Werkstoffe. VDI-Buch. Springer, Berlin.

DOI: 10.1007/978-3-540-68112-0

[14] Huang, C.-C. and Cheng, J.-H. 2004. An investigation into the forming limits of sintered porous materials under different operational conditions. Journal of Materials Processing Technology 148, 3, 382–393.

DOI: 10.1016/j.jmatprotec.2003.10.024

[15] Narayanasamy, R., Ramesh, T., and Pandey, K. S. 2008. Some aspects on cold forging of aluminium–iron powder metallurgy composite under triaxial stress state condition. Materials & Design 29, 4, 891–903.

DOI: 10.1016/j.matdes.2006.05.005

[16] Mohan Raj, A. P. and Selvakumar, N. 2011. Deformation Behavior of Sintered Fe-C-Mn Composite During Cold Upset Forming. Materials and Manufacturing Processes 26, 11, 1388–1392.

DOI: 10.1080/10426914.2010.544820

[17] Prasanna Kumar, U. J., Gupta, P., Jha, A. K., and Kumar, D. 2016. Closed Die Deformation Behavior of Cylindrical Iron–Alumina Metal Matrix Composites During Cold Sinter Forging. J. Inst. Eng. India Ser. D 97, 2, 135–151.

DOI: 10.1007/s40033-015-0089-1

[18] Depp, J. C., Ilia, E., and Hähnel, M. 2005. Neue hochfeste Werkstoffe für sintergeschmiedete Pleuelstangen. MTZ - Motortechnische Zeitschrift 2005, 4, 292–298.

DOI: 10.1007/bf03226735

[19] Esper, F. J. 1996. Pulvermetallurgie. Das flexible und fortschrittliche Verfahren für wirtschaftliche und zuverlässige Bauteile ; mit 15 Tabellen. Kontakt & Studium Bd. 494. Expert-Verl., Renningen-Malmsheim.

[20] Washburn, E. W. 1921. The Dynamics of Capillary Flow. Phys. Rev. 17, 3, 273–283.

[21] Rajeshkannan, A. 2010. Workability studies on cold upsetting of sintered copper alloy preforms. Mat. Res. 13, 4, 457–464.

DOI: 10.1590/s1516-14392010000400006

[22] Sandner, C., Ratzi, R., Lorenz, B., and Tobie, T. 2002. Sintered gears - achievable load-carrying capacities by conventional and new production methods. March 13-15. International conference on Gears, Vol. 1.