Formability and correlation between formability indices of Al-0.9Mg-1.0Si-0.7Cu-0.6Mn alloy for automotive body sheets

The texture, the formability and the correlation between formability indices of A1-0.9-Mg1.0Si-0.7Cu-0 6Mn alloy for automotive body sheets subjected to solid solution, T4, annealing treatment and artificial aging at 443k for different time were investigated by orientation distribution functions(ODF) analysis, tensile and cupping test, FLD measurement and regression analysis method. The results showed that the textures of cold rolled alloy sheets consist mainly of copper and brass orientations, which are transformed into the texture mainly containing {001}< 310 > orientation after recrystallization, and aging treatment has little influence on the recrystallization texture. The formability of alloy sheets subjected to solid solution, T4 and annealing treatment is similar, however, the formability was observably deteriorated after aging at 443k. The correlation between uniform elongation delta(u) and FLD(0) is the most remarkable in all the given formability indices, the correlation between strain-hardening exponent n and the FLD(0) take second place, while there is no correlation between plastic strain ratio r and FLD(0). The correlation between reduction of area and cupping value I(E) is distinct, while psi and I(E) have little correlation with FLD(0).