Experimental Evaluation of Cold Forging Lubricants Using Double-Cup-Extrusion-Tests

Abstract:

Cold forging processes enable the economical production of high quality components like joints, shafts and gears. The manufactured parts are characterized by improved properties such as hardness, surface quality and fatigue strength. For manufacturing components using cold forging, a comprehensive knowledge regarding the cold forging procedure and its process parameters is needed. One important influencing factor, which needs to be analyzed to use the potential of this kind of processes, is the tribological system, especially the used lubricant. The tribological conditions significantly influence the material flow and thus the workpiece quality. Furthermore, resource efficient and environmentally benign metal forming processes became very important within the last decade. The present study evaluates the resulting tribological conditions and their differences for various cold forging lubricants with and without a zinc phosphate based lubricant carrier. The lubricants are based on molybdenum disulphide, polymers, or both inorganic salts and waxes. The tribological conditions of the different lubricants are investigated using the Double-Cup-Extrusion-Test (DCET) as a laboratory friction test.

• Periodical: Materials Science Forum (Volume 918)
• Pages: 65-70
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.918.65
• Online since: March 2018
• Authors: Robby Lorenz*, Hinnerk Hagenah, Marion Merklein
• Keywords: Cold Forming, Gear, Lubrication, Steel, Tribology

References

[1] W. Niefer, Die Umformtechnik im Substitutionswettbewerb mit anderen Technologien, Tagungsband 3. Umformtechnisches Kolloquium Darmstadt (1988).

[2] F. Dohmann, N. Lüttel, Einfluß der Reibung auf die Qualität fließgepreßter Verzahnungen, Maschinenmarkt Würzburg 101 (1995) 20–23.

[3] N. Bay, The state of the art in cold forging lubrication, J. Mater. Process. Technol. 46 (1994) 19–40.

[4] J. Donofrio, Zinc phosphating, Metal Finishing 108 (2010) 40–56.

DOI: 10.1016/s0026-0576(10)80212-0

[5] M. Takeuchi, N. Kashimura, F. Oda, Development of environmentally friendly lubricant with high performance and simple treatment for cold forging, J. JSTP 41 (2000) 109–114.

[6] J. Schoppe, Innovative cold massive forming on phosphate-free semi-finished products, Neuere Entwicklungen in der Massivumformung (2003) 305–312.

[7] M. I. Ghobrial, J. Y. Lee, T. Altan, N. Bay, B. G. Hansen, Factors affecting the double cup extrusion test for evaluation of friction in cold and warm forging, CIRP Ann. Manuf. Techn. 42 (1993) 347–351.

DOI: 10.1016/s0007-8506(07)62459-7

[8] T. Nakamura, Y. Sumioka, I. Ishibashi, M. Sekizawa, Lubrication performance of environmentally friendly lubricants for forging, Proc. Jap. Joint Conf. Techn. Past. (2008) 333–334.

[9] G. Ngaile, J. Cochran, D. Stark, Formulation of polymer-based lubricant for metal forming, Proc. Inst. Mech. Engi. Part B 221 (2007) 559–568.

DOI: 10.1243/09544054jem659

[10] M. Gariety, G. Ngaile, T. Altan, Evaluation of new cold forging lubricants without zinc phosphate precoat, Int. J. Mach. Tool Manu. 47 (2007) 673–681.

DOI: 10.1016/j.ijmachtools.2006.04.016

[11] K. Andreas, M. Merklein, Influence of surface integrity on the tribological performance of cold forging tools, Procedia CIRP 13 (2014) 61–66.

DOI: 10.1016/j.procir.2014.04.011

[12] R. Geiger, Metal flow in combined cup extrusion, Reports Inst. for Form. Techn. 36 (1976).

[13] M. Kleinle, Etablierte Schmierstoffsysteme in der Kaltmassivumformung, 24. Jahrestreffen der Kaltmassivumformer (2009).

[14] S. Lenzer, Neue Tribo-Systeme für die Kaltumformung, 22. Jahrestreffen der Kaltmassivumformer (2007).

[15] S. Wohletz, C. Müller, S. Zang, P. Groche, Entwicklungen in der konversionsschichtfreien Kaltmassivumformung (2013) 120–131.