Determination of Mechanical Properties for the Hydroforming of Magnesium Sheets at Elevated Temperature

Article Preview

Abstract:

Thanks to the low weight, magnesium alloys feature high specific strength and stiffness properties. Thus they prove to be promising materials for todays ambitious automotive light weight construction efforts. Due to their comparative low formability at room temperature the process of magnesium sheet hydroforming can be improved at temperatures higher than 200 °C by the activation of additional sliding planes. This paper illustrates the determination of mechanical properties for the hydroforming of magnesium sheets at elevated temperature. In particular the mechanical behavior at elevated temperature was investigated by means of the tensile test and of the hydraulic bulge test. For the determination of the strains an optical measurement system was introduced into the experimental set-up. The exact knowledge of the strain condition in the area of diffuse necking enabled the determination of the flow curve in the tensile test also beyond the uniform elongation. The influence of temperature and strain rate was analyzed as well as the influence of uni- and biaxial stress state on the flow curve. Using circular and elliptic dies with different aspect ratio the hydraulic bulge test served to determinate the forming limit curves at three different elevated temperatures.

You might also be interested in these eBooks

Info:

Periodical:

Pages:

779-786

Citation:

Online since:

May 2005

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2005 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] M. Geiger, M. Merklein, M. Celeghini, H. -G. Haldenwanger, M. Prier.: Wirkmedienbasierte Umformung von Rohren und Blechen bei erhöhten Temperaturen. In: Siegert K. (Hrsg. ) Hydroumformung von Rohren, Strangpressprofilen und Blechen. 28. -29. 10. 2003, FellbachStuttgart. p.273.

Google Scholar

[2] H. Friedrich, S. Schumann: Research for a new age of magnesium in the automotive Industry, Journal of Materials Processing Technology 117 (2001) p.276.

DOI: 10.1016/s0924-0136(01)00780-4

Google Scholar

[3] E. Doege, K. Dröder: Sheet metal forming of magnesium wrought alloys - formability and process technology, Journal of Materials Processing Technology 115 (2001) p.14.

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

Google Scholar

[4] Europäische Norm EN 485-2.

Google Scholar

[5] Aramis Users Manual V5. 3, GOM mbH, Braunschweig, Germany.

Google Scholar

[6] F. Gologranc: Beitrag zur Ermittlung von Fließkurven im kontinuierlichen hydraulischen Tiefungsversuch, Dissertation, Institute for Metal Forming Technology, University of Stuttgart, Germany, (1975).

Google Scholar