Evaluating structural integrity of cast Al–7% Si–Mg alloys via work hardening characteristics: 1. Concept of target properties

We analyzed the tensile behavior of Al–7 wt.% Si–Mg alloys with three different Mg contents (0.20, 0.40, and 0.60 wt.%). We found that the Kocks–Mecking (KM) model adequately expresses the Stage III work hardening of these alloys. Specimens with major structural discontinuities fractured before the completion of Stage III hardening. We developed a method to predict the end of Stage III work hardening of specimens that failed prematurely due to the presence of structural discontinuities. Based on this concept, we introduce target stress and elongation which can be used as quality assessment criteria to evaluate the structural integrity of castings.