Effect of filtration on the morphology and mechanical properties of Mg molten alloy entering the mould cavity

摘要

In this research, the experiments were carried out in two methods. In the first, the foam filter has been placed at the gate or runner of the mould, and in the second, no filter was used. In both methods, the casting temperatures were 680 C and 750 C. A pyrex glass plate was used on one side of the mould cavity in order to evaluate the morphological behaviour of entering melt into the cavity. The height of filtered molten Mg-Al-Zn alloy in mould was increased step-by-step with the filling time. This showed that the filtered molten alloy flows in mould cavity with different velocities. In case of no filtered molten alloy this was not observed. The reliability of the results of bending tests has been evaluated by Weibull analysis. The filters had absorbed the inclusions very well. A fracture toughness of 260 MPa was obtained in specimen poured at 680 C with ceramic filters. The Weibull plots showed that the castings filtered at the gate at temperature of 680 C had the best reliability.