Correlation between Numerical Simulation Results and Empirical Ones in Permanent Mould Gravity Casting of AM60B Magnesium Alloys

Mechanical and microstructural characterisations have been performed on AM60B magnesium alloy castings, obtained by permanent mould gravity casting. Static tensile tests results have been effectively related to microstructural parameters, due to the use of an optimised mould specifically designed to minimise the presence of defects in magnesium alloys castings. In this paper these relations are investigated, as well as the benefits of using the numerical simulation as a predictive tool for the final properties of magnesium alloy castings obtained by gravity casting processes. The redesigned mould prevented impurities to enter the die cavity and allowed a laminar flow of the metal through the gate. Moreover, defects formation has been investigated using criteria functions provided by the simulation software, and the results confirmed the reliability of the die design. Better mechanical properties can be expected and, by comparing the simulation results with the experimental ones, it's possible to verify a good correspondence thus allowing to establish semi-empirical rules to forecast the final castings’ properties.