Yielding description for solution strengthened aluminum alloys

In this work, yield surfaces were measured for binary aluminum-magnesium sheet samples which were fabricated by different processing paths to obtain different microstructures. The yielding behavior was measured using biaxial compression tests on cubic specimens made from laminated sheet samples. The yield surfaces were also predicted from a polycrystal model using crystallographic texture data as input and from a phenomenological yield function proposed previously. In general, experimental and predicted yield surfaces were found to be in relatively good agreement. However, for samples processed with high cold rolling reduction prior to solution heat treatment, a significant difference was observed between the phenomenological yield surface and the experimental/polycrystal yield surfaces in the pure shear region. In this paper, a refinement was proposed for the phenomenological yield description to account for the behavior of the solute strengthened aluminum alloy sheets studied in this work, and in general, for any sheet metal. This yield function was implemented into a finite element code and sample computations were carried out to assess the validity and the accuracy of this improved material description.