Abstract: In order to improve the ductility or formability of a magnesium alloy, addition of rare earth elements or refinement of grain size is often used. However, conventional additional elements inhibit the action of grain boundary sliding for complementing plastic deformation. Therefore, it is required to search for additional elements that act to facilitate the grain boundary sliding not only at a conventional deformation speed but also in a higher speed range while maintaining a microstructure for activating non-basal dislocation. The present invention is to provide a wrought processed Mg-based alloy having excellent ductility at room temperature, which consists of 0.25 mass % or more to 9 mass % or less of Bi, and a balance of Mg and inevitable components, and is characterized by having an average grain size of an Mg parent phase after solution treatment and hot plastic working after casting of 20 ?m or less.

Abstract: In order to improve the ductility or formability of a magnesium alloy, addition of rare earth elements or refinement of grain size is often used. However, conventional additional elements inhibit the action of grain boundary sliding for complementing plastic deformation. Therefore, it is required to search for additional elements that act to facilitate the grain boundary sliding not only at a conventional deformation speed but also in a higher speed range while maintaining a microstructure for activating non-basal dislocation. The present invention is to provide a wrought processed Mg-based alloy having excellent ductility at room temperature, which consists of 0.25 mass % or more to 9 mass % or less of Bi, and a balance of Mg and inevitable components, and is characterized by having an average grain size of an Mg parent phase after solution treatment and hot plastic working after casting of 20 ?m or less.