Optimizing a Step Casting Geometry to Evaluate the Mechanical Properties of AM60B Magnesium Alloys

The purpose of the research was the optimization of an existing permanent mould in order to achieve sound and reliable Mg alloy castings. To understand how the existing runner system affected the filling behaviour, specific process parameters were investigated. In particular both the material and the die temperatures, and the filling parameters, were analysed using MAGMASOFT® software. Firstly, the computational approach allowed to understand that the whole casting process had to be within 4÷5 seconds in order to not produce freezing phenomena, but anyway turbulence was still present. It was clearly evident that the main problem was in the die geometry, so the decision to design a new one. The ingates were redesigned, as well as the “non-returning” trap. A better control of the molten metal ingate speed was also obtained by adding a filter. By this configuration an adequate flow rate was achieved to not produce freezing phenomena and a significant reduction of turbulences. The present work shows a comparison of the simulation results to evidence how an optimized design of the runner system can significantly reduce the presence of casting defects, allowing to identify the real mechanical properties of AM60B Mg alloys.