Effects of zinc and manganese contents on extrudability of Mg–Al–Zn alloys

Abstract

The effects of zinc and manganese content on extrudability of Mg–Al–Zn system alloys have investigated. Zinc enhanced occurrence of surface cracks. Hence,as the zinc content increased, the extrusion speed limit became low. When the manganese and zinc content was high, the surface oxide film was thick and the surface color of the extrusion was black. On the other hand, manganese had the effect of increasing the tensile strength, 0.2% proof stress and elongation. Manganese enhanced the dynamic recrystalization in the extrusion process. As the result, the grain size of the extrusion was small.