Multi-scale model for the ductility of multiple phase materials

A multi-scale model for the ductility of multiple phase materials has been developed in this paper. The model can be used to quantify the effects of various types of the second phase particles (including cracking formation phases and non-cracking formation phases) on the ductility of a multiple phase material. The model calculation indicates that the volume fraction, cracking fraction and shape factor of the cracking formation phases (CFPs), and the volume fraction and size of the non-cracking formation phases (NCFPs) have important effects on the ductility of a multiple phase material. It has been shown that the model predictions are in good agreement with the experimental data when applying the model to an Al–Zn–Mg alloy, in which the ductility of the material decreases with aging time until the alloy reaches the peak-aged stage, afterwards the ductility increases. The most important feature of the model is that calculation of the macroscopic ductility of a multiple phase material requires only a small amount of time and cost, compared to other models based on finite element method (FEM).