AZ계열 마그네슘 합금의 알루미늄 함량에 따른 고온변형 중 집합조직 형성 거동

Abstract

Magnesium and its alloy have been paid good attention in various industrial fields due to having an excellent specific strength property compare to other materials. The possibility of weight reduction can be linked to lower fuel consumption and lower green gas emission. However, the major obstacle of their commercialization is low room temperature formability due to insufficient slip system associated with hexagonal close-packed crystal structure. Also, hexagonal close-packed crystal structure metal have a low symmetry properties. Especially, The existence of texture which formed by high-temperature deformation affects not only the subsequent formability but also mechanical properties. Therefore understanding of texture formation mechanism and their controlling during high-temperature deformation on magnesium alloy plays an important role in academic and industrial fields. In order to improve the formability, many studies on texture control have been extensively investigated, whereas studies on the effect of the solute element on the formation of the texture is insufficient. In order to clarify the effect of aluminum concentration on texture formation behavior, three AZ system magnesium alloy which having a different aluminum concentration (AZ31, AZ61 and AZ91) were performed high-temperature uniaxial compression tests in this study. Each AZ system magnesium alloys were machined out and rolled with a rolling reduction of 30% at 673K. Uniaxial compression test specimens were annealed at 723K for 1h. Uniaxial compression tests were carried out in various deformation conditions. After deformation, Texture measurements and crystal orientation distribution were conducted by X-ray diffraction methods on mid-plane section of the specimens. In this study, fiber texture was formed and dynamic recrystallization was occurred regardless of the deformation conditions. Also, it is notable that increasing aluminum concentration lead to more accumulation of basal texture.