Lightening structure is one of the goals of many fields of research. As a result, magnesium alloys are studied due to their low density. However, one drawback of these alloys is their low formability at room temperature due to their hexagonal closed-packed structure. In the present work, the forming capacity of an AZ31 Mg alloys has been studied using a mini deep-drawing device, image correlation techniques and tests (tension and expansion) at temperatures contained between 20°C and 200°C. To investigate formability limits of Mg alloys in expansion, major and minor strains data were generated using hemispherical punch tests and analyzed with 3D digital images correlation techniques. Thanks to images correlation, strains on the surface of the samples were observed by means of a double digitization of the sample in three dimensions before and after deformation by using stereoscopic vision and triangulation. Image correlations have also been used in 2D to measure strains on the surface of the tensile test samples. These tests gave interesting information on the evolution of various parameters such as hardening coefficient, strain rate sensitivity parameter, and Lankford coefficient, which may affect the behavior of the alloys. Finally, the forming limits in both configurations (tension and expansion) were compared and discussed.
Cite this paper
R. Boissiere, P. Vacher, J. Blandin and A. Khelil, "Strain Capacities Limits of Wrought Magnesium Alloys: Tension vs. Expansion," Materials Sciences and Applications
, Vol. 4 No. 12, 2013, pp. 768-772. doi: 10.4236/msa.2013.412097
 G. Reyes and H. Kang, “Mechanical Behavior of Lightweight Thermoplastic Fiber-Metal Laminates,” Journal of Material Processing Technology, Vol. 186, No. 1-3, 2007, pp. 284-290.http://dx.doi.org/10.1016/j.jmatprotec.2006.12.050
 A. K. Ghosh and S. S. Hecker, “Stretching Limits in Sheet Metals: In-Plane versus Out of Plane Deformation,” Metallurgical and Materials Transactions B, Vol. 5, 1974, pp. 2161-2164.
 E. Hsu, J. E. Carsley and R. Verma, “Development of Forming Limit Diagrams of Aluminum and Magnesium Sheet Alloys at Elevated Temperatures,” Journal of Materials Engineering and Performance, Vol. 17, No. 3, 2008, pp. 288-296. http://dx.doi.org/10.1007/s11665-007-9196-y
 R. Boissière, P. Vacher and J. J. Blandin, “Influence of the Punch Geometry and Sample Size on the DeepDrawing Limits in Expansion of an Aluminium Alloy,” International Journal of Forming, Vol. 3, Suppl. 1, 2010, pp. 135-138. http://dx.doi.org/10.1007/s12289-010-0725-0
 P. Vacher, S. Dumoulin, F. Morestin and S. MguilTouchal, “Bidimensional Strain Measurement Using Digital Images,” Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, Vol. 213, No. 8, 2010, pp. 811-817.
 R. Boissière, “Effet de la Temperature sur les Capacités de Mise en Forme d’Alliages de Magnésium Corroyés,” Ph.D. Thesis, Grenoble University, Grenoble, 2008.