New mechanical stirring system to study the rheological behaviour of semisolid A380 second melting aluminium alloy

Abstract The design and manufacture of a new mechanical stirring system to obtain a globular structure by semi-solid state forming and its double functionality as a rheometer is presented. The main objective of the Partial Melting Semisolid Manufacturing (PMSM) machine is to obtain a globular microstructure by controlling the viscosity of the A380 second-melt aluminium alloy. In addition, the PMSM device is validated as a rheometer to determine viscosity as a function of temperature. For this purpose, studies were carried out with the same alloy. The results are compared with those obtained for the same conditions with a commercial rheometer. Viscosity control is an innovation compared to traditional mechanical stirring machines, that use time as control parameter. The results of the experimentation gave mainly a dendritic microstructure. However, some rosette/globular microstructure was also obtained in the experiments. This experimentation allows validating the equipment by performing its function optimally.