Superplasticity of an AZ91 Magnesium Alloy


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The superplastic deformation characteristics of the AZ91, the mostly used magnesium alloy, were investigated at various strain rates in the interval from 3x10-5 to 1x10-2 s-1 and temperature of 420 °C. To prepare superplastic alloys thermo-mechanical treatment was used. Cast materials were heat-treated in two stages, after homogenization at 415 °C for 10 h were submitted to the precipitation annealing at temperature in the range of 200-380 °C for 10 h, and deformed by hot extrusion. Microstructure of samples was observed by the light microscope Olympus. Strain rate sensitivity parameter m has been estimated by the abrupt strain rate changes method. The strong strain rate dependence of the m-parameter was found. The highest elongation to failure, 584%, was found for the samples aged at 380 °C. Possible physical mechanisms of the superplastic flow are discussed.



Materials Science Forum (Volumes 567-568)

Edited by:

Pavel Šandera




Z. Száraz et al., "Superplasticity of an AZ91 Magnesium Alloy", Materials Science Forum, Vols. 567-568, pp. 365-368, 2008

Online since:

December 2007