Development of rheology vacuum low-pressure die casting with electromagnetic stirrer and vacuum system

Abstract

In this study, a rheology vacuum low-pressure die caster is developed by installing a vacuum system in the die and an electromagnetic stirrer in the rasing pipe of a low-pressure die casting system. The cavity dimensions are 130 mm in the filling direction and 110 mm in the vertical direction, with a thickness of 1 mm. The fluidity of the material inside the die cavity is improved by maintaining the vacuum state inside the die. The electromagnetic stirrer is attached to the outside of the rasing pipe, which connects the furnace to the lower die. The application of the electromagnetic stirrer enables the achievement of microstructure with fine and globular primary α-Al particles by disrupting the dendrite structure. A mild filling simulation is conducted using a commercial casting analysis program prior to an experiment with the rheology vacuum low-pressure die caster. The rheological behaviour of the material inside the die is observed. A rheological thin plate is fabricated by applying a melt temperature of 615 °C, a vacuum of 60 Torr, and a gas pressure of 15 bar. There is little eutectic structure, with primary aluminium grains of 30 µm or below that are mostly distributed due to the effects of stirring. The tensile strength and elongation are 120 MPa and 15%, respectively. The hardness is 61–66 HV.