Evaluation of the AZ31 Formability According to Temperature Using a Constant Strain Rate Test

Abstract:

The present paper is focused on the Finite Element modeling of the Marciniak stretch-forming test in warm condition. Such a test was proposed by the authors for evaluating the warm formability of the Mg alloy AZ31 according to the most important parameters: the temperature and the strain rate. Tensile tests confirmed the large influence of the strain rate on the deformation of the AZ31, especially when the test temperature is over 200°C. Three dimensional FE simulations were thus carried out in order to analyze the strain and strain rate evolutions during the formability test at the temperature of 200°C. In particular, simulations were aimed at investigating the effect of the specimen’s geometry on the strain rate evolution in the central region, where failure occurs during the Marciniak stretch-forming test. An equation for calculating the punch speed profile able to keep a constant equivalent strain rate in the central region of the specimen has been furnished according to the geometry of the specimen. Its efficiency was validated by means of additional simulations implementing the punch speed profile calculated using the proposed approach.

• Periodical: Advanced Materials Research (Volumes 83-86)
• Pages: 375-383
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.83-86.375
• Online since: December 2009
• Authors: G. Palumbo, Donato Sorgente, Luigi Tricarico
• Keywords: Finite Element Analysis (FEA), Marciniak’s Stretch-Forming Test, Strain Rate, Warm Formability

References

[1] H. Friedrich, S. Schumann, Research for a new age of magnesium, in the automotive industry, J. Mater. Process. Technol. 117 (2001) 276-281.

[2] J. Carpenter, J. Jackman, N. Li, R. Osborne, B. powell, P. Sklad, Automotive Mg research and development in North America, Mat. Sci. Forum 546-549 (2007) 11-24.

DOI: 10.4028/www.scientific.net/msf.546-549.11

[3] E. Doege, K. Droeder, Sheet metal forming of magnesium wrought alloys - formability and process technology, J. Mater. Process. Technol. 115 (2001) 14-19.

DOI: 10.1016/s0924-0136(01)00760-9

[4] D.L. Yin, K.F. Zhang, G.F. Wang, W.B. Han, Warm deformation behaviour of hot-rolled AZ31 Mg alloy, Mater. Sci. Eng., A 392 (2005) 320-325.

DOI: 10.1016/j.msea.2004.09.039

[5] G. Palumbo, L. Tricarico, Numerical and experimental investigations on the Warm Deep Drawing process of circular aluminum alloy specimens, J. Mater Proc. Tech. 184 (2007) 115-123.

DOI: 10.1016/j.jmatprotec.2006.11.024

[6] G. Palumbo, D. Sorgente, L. Tricarico, Numerical-experimental analysis of thin magnesium alloy stripes subjected to stretch-bending, J. Mater. Process. Technol. 201/1-3 (2008) 183- 188.

DOI: 10.1016/j.jmatprotec.2007.11.242

[7] Fuh-Kuo Chen, Tyng-Bin Huang, Formability of stamping magnesium-alloy AZ31 sheets, J. Mater. Process. Technol. 142 (2003) 643-647.

DOI: 10.1016/s0924-0136(03)00684-8

[8] K.F. Zhang, D.L. Yin, D.Z. Wu, Formability of AZ31 magnesium alloy sheets at warm working conditions, Int. J. Mach. Tools Manuf. 146 (2006) 1276-1280.

DOI: 10.1016/j.ijmachtools.2006.01.014

[9] K. Siegert, S. Jaeger, M. Vulcan, Pneumatic bulging of magnesium AZ31 sheet metals at elevated temperatures, CIRP Ann. 52 (2003) 241-244.

DOI: 10.1016/s0007-8506(07)60575-7

[10] Y.S. Lee Y.N. Kwon, S.H. Kang, S.W. Kim, J.H., Forming limit of AZ31 alloy sheet and strain rate on warm sheet metal forming, J. Mater. Process. Technol. 201 (2008) 431-435.

DOI: 10.1016/j.jmatprotec.2007.11.306

[11] T. Naka, G. Torikai, R. Hino, F. Yoshida: The effects of temperature and forming speed on the forming limit diagram for type 5083 aluminum-magnesium alloy sheet; J. Mater. Process. Technol. 113, (2001) 648-653.

DOI: 10.1016/s0924-0136(01)00650-1

[12] G. Palumbo, D. Sorgente, L. Tricarico, The design of a formability test in warm conditions for an AZ31 magnesium alloy avoiding friction and strain rate effects, accepted for publication in the Int. J. Mach. Tools Manuf.

DOI: 10.1016/j.ijmachtools.2008.06.010

[13] P.J. Bolt, R.J. Werkhoven, A.H. van den Boogard, Warm Deep Drawing of Aluminium Sheet, in: Proc. of the She-Met Int. Conf., Belfast, 14th-16th April (2003).