Microstructure and mechanical properties of magnesium AZ31 sheets produced by extrusion

In the last decade magnesium has regained importance for lightweight and transportation industries since it is the lightest metal for structural applications. Therefore the increasing demand of sheet-like magnesium applications required manifold forming strategies. The extrusion is an alternative solution for the production of magnesium sheets and thin flat profiles, which are produced today mainly by rolling. This study presents the influence of the process temperature and extrusion ratio on the microstructure and mechanical properties of AZ31 extrusion sheets. The extruded sheets exhibit a coarse-grained microstructure and a pronounced mechanical anisotropy in the sheet plane caused by the extrusion texture. This texture leads to a strong dependence of deformation systems on the loading direction delivering the highest value for yielding in extrusion direction, but the lowest in transverse direction due to the easy activation of the {10-12} extension twinning system in favorably oriented grains.