Deep drawing of ZK60 magnesium sheets fabricated using ingot and twin-roll casting methods

Abstract

Deep drawing was carried out on two different ZK60 (Mg-Zn-Zr) magnesium sheets fabricated via ingot and twin-roll casting methods. The effects of the microstructure and texture on the deep drawability and the associated microstructural evolution of ZK60 alloys were examined. Twin-roll casted sheets with refined particles were stronger and showed greater elongation than ingot-casted sheets. Moreover, they were fully deep-drawn at lower temperatures than ingot-casted sheets, and the deep drawability of the ingot-casted sheets was better at a high deformation rate compared to that of the twin-roll casted sheets. During the deep drawing process, the ingot-casted sheets with large grains experienced more tensile twinning than the twin-roll casted sheets, and shear bands were observed. The twin-roll casted sheets revealed peak broadening of the basal texture along the TD and peak splitting along the RD. Thickness variations of the drawn cups showed that the twin-roll casted sheets resisted wall thinning more effectively than the ingot-casted sheets.