Predicting the Influence of Microporosity on the Mechanical Properties and Fracture Behavior of High-Pressure Die-Cast AM50 Magnesium Alloy

In this paper, experimental and finite element modeling methods were adopted to investigate the effects of microporosity on the tensile properties and fracture behavior of high-pressure die-casting (HPDC) AM50 alloy. By specimen-to-specimen fractographic analysis, the variability in tensile properties could be quantitatively correlated with the areal fraction of the porosity presented in the corresponding fracture surfaces by using a simple power law equation. Numerical models of synthetic microstructures with different pore sizes, areal fractions of pores and pore distributions were established. Based on the experimental and numerical simulation results, it could be concluded that the fracture will initially occur in the region where has the highest intensity of equivalent stress field (i.e., contains the most highly localized cluster of pores and shrinkage), and then, fracture crack will fast propagate through the adjacent regions which have the relatively high intensity of stress field.