자동차용 Al-6wt%Mg 합금에서 중간어닐링이 소성이방성에 미치는 영향

Abstract

The effects of intermediate annealing on the plastic anisotropy were investigated in Al-6 wt%Mg alloy sheets for automobile application. Intermediate annealing was adopted to improve the formability in Al-Mg alloys. For two different conditions of O and T4 treatment, textures were analyzed by using orientation distribution function method. The plastic anisotropy properties were evaluated by measuring R values, and then compared them with caculated R values from quantitative texture data. The stretch forming properties were also evaluated by using work hardening exponents. Intermediate annealing decreased the deformation textures, which had an influence on the development of recrystallization textures during final heat treatment. Isotropy and stretch forming properties were decreased in the axis of 45˚ to rolling direction for O treatment due to highly remained deformation textures. Whereas anisotropy and stretch forming properties were increased in the axis of 45˚ to rolling direction for T4 treatment due to well-developed recrystallization textures of rotated cube along normal direction.