Effect of Lubrication Conditions on the Forming Limit of Deep Drawing of 6061 Aluminum Alloy Sheet

Abstract:

With the development of lightweight vehicles, aluminum alloy sheets are increasingly used in the automotive field. However, the aluminum alloy sheet has poor forming performance at room temperature. Therefore, how to improve the sheet metal forming performance of aluminum alloy sheet has become one of the current research hotspots. In this paper, the effects of different lubricants on the deep drawing forming properties of 6061 aluminum alloy sheets were studied by cupping experiments. The effects of lubricants on the deep drawing of sheet metal forming and the wall thickness of cups after deep drawing were explored. The results show that under the condition of drawing speed of 3MPa and 200mm/min, the ultimate drawing ratio of the sheet under oil lubrication is 1.92, and the PTFE film is 2.16. Grease and graphite lubrication are respectively 2.12 and 2.03, using PTFE film lubrication can increase by about 10% contrast with the oil lubrication. The measurement of the wall thickness of the cup under the forming limit state shows that the position with the largest reduction rate appears in the rounded transition zone, and the wall portion of the cylindrical member increases with the height of the wall, and the thickness from the bottom of the cup to the bottom of the cup. The edges all show a trend of decreasing first and then increasing.

• Periodical: Materials Science Forum (Volume 944)
• Pages: 85-91
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.944.85
• Online since: January 2019
• Authors: Yan Qi Wang, Yong Qi Cheng*, Peng Zhang, Gan Luo, Peng Bin Li, Kui Jiang
• Keywords: 6061, Forming Limit, Limit Draw Ratio, Lubrication Mechanism, Sheet Metal Forming

References

[1] P. Saggu, D. Cory, D. Pushin, et al. Influence of the forming process on crash and fatigue performance of high strength steels for automotive components, Bulletin of the American Physical Society, (2002).

[2] J.F. Fan, M. Chen, Ordinary discussion on the way toward the lightweighting of chinese automobile, Foundry, 55(10) (2006) 995-998.

[3] H.M. Zhu, The application and development of key technologies in automotive weight lightening, Applied Energy Technology, (2) (2009) 10-12.

[4] Y.Q. Guo, X.F. Zhu, Y. Yang, et al. Forging & Stamping Technology, 40(3) (2015).

[5] W.S. Miller, L. Zhuang, J. Bottema, et al, Recent development in aluminium alloys for the automotive industry, Materials Science & Engineering A, 280(1) (2000) 37-49.

DOI: 10.1016/s0921-5093(99)00653-x

[6] G. Ingarao, R.D. Lorenzo, F. Micari. Sustainability issues in sheet metal forming processes: an overview, Journal of Cleaner Production, 19(4) (2011) 337-347.

DOI: 10.1016/j.jclepro.2010.10.005

[7] N. Shahmanesh, Lightening the material, Automotive Engineer, (2003).

[8] P.K. Mallick, Materials, design and manufacturing for lightweight vehicles, Crc Press, (2010).

[9] J.D. Mao, Y. Xu, H. Wang, et al. Influence of lubrication on the property of bulging and drawing, Machine Building and Automation, 37(5) (2008) 40-42.

[10] X.W. Fan, Research on forming crack state of metal drawn parts based on solid-liquid lubrication, Jiangsu University, (2012).

[11] M. Li, Principles of Metal Plastic Forming. 2nd ed, Machinery Industry Press, (2013).

[12] GB /T 15825. 3-2008，Sheet metal formability and test methods—Part 3: Drawing and drawing load test [S].

[13] H.Y. Qiu, Y.J. Huang, The influence of friction on sheet metal stamping formability, Die & Mould Industry, 1 (2005) 69-71.

[14] Y.X. Cheng, D. Cheng, Application of polyethylene film in deep drawing, Metal Processing: Hot Working, 6 (1995) 16-16.

[15] Zhou G.R., Fluid Lubrication Theory [M]. Zhejiang University Press, (1990).

[16] J.G. Wang, J.Z. Zhang, On formation and breakup of boundary lubricating layer, Lubrication and Sealing, 6 (2005) 4-8.