Abstract
Magnesium alloys have special features such as light weight, high specific strength, and good reusability. However, information on the compressive formability of magnesium alloys in multi-axial compressive stress conditions is still limited, nevertheless of their importance in plastic working processes such as forging and extrusion. In the present study, biaxial compression tests of initially isotropic cast AZ31 magnesium alloy were performed along proportional and non-proportional strain paths at room temperature. In the tests, the change of microstructure was observed using a scanning electron microscope. The results revealed that the compressive forming limit of AZ31 magnesium alloy was affected not only by the maximum shear stress but also by the hydrostatic stress. The area fraction of twin, which influences on the compressive flow behavior, was found to vary according to the strain paths.
