Abstract:A newly developed technology for manufacturing magnesium alloy strip, vertical twin-roll strip casting, has been described. This manufacturing process is easy to be facilitated in an economical way to manufacture wrought magnesium alloy strips. As an example, AZ31 magnesium alloy was used to investigate the appropriate manufacturing conditions for vertical twin-roll strip casting by varying the temperatures of the molten materials and rolling speeds. The effects of manufacturing conditions on forming quality were clarified in terms of roll speeds and casting temperature. In addition, microscopic observation and X-ray diffraction of the as-cast strips were performed. It has been determined that AZ31 alloy strip of 1−3 mm in thickness can be produced at a speed of 30 m/min by a vertical twin-roll caster. The microstructure of as-cast strip only contains α-phase (Mg) and no other phase, and the twin-roll casting process can effectively refine the grain size. The fine equiaxed grain of as-cast strips is beneficial to the plastic deformation of the strips, and it is also suitable for direct cold-rolling with a maximum cold-rolling reduction of 40%.

Key words: AZ31 magnesium alloy; vertical twin-roll casting; cold rolling; microstructure; tensile properties