| Semi-solid casting or thixocasting presents an interesting way to produce parts with low porosity and shrinkage and heat treatable in order to improve their mechanical properties. This method is however in competition with conventional die casting. In this project, the microstructural and mechanical characteristic of two magnesium alloys (AZ91D and AJ62x) moulded from semi-solid and liquid state were determined and compared. Billets were casted in permanent mould with or without electromagnetic stirring during solidification. From these billets, parts were injected from the liquid and the semi-solid states. A simple and rapid method was developed in order to determine the temperature of injection of the thixocast parts. Tensile, impact and creep properties were measured on samples cut off from these castings. The analysis of microstructure, composition and phases was also made. |
