An investigation of flow characteristics considering the effect of viscosity variation in the thixoforming process

The semi-solid forming process (thixoforming, rheocasting) is a novel forming process that has some advantages compared to conventional die casting, squeeze casting and hot/cold forging. In this study, the thixoforming process was selected for analysis in terms of billet handling and ease of the automation process. The thixoforming process consists of a re-heating process of the billet, billet handling, filling into the die cavity and solidification of the SSM part. In the filling process, two rheological models, i.e., a Newtonian and a non-Newtonian model (Ostwald–deWaele), were verified with experimental results. The Ostwald–deWaele model shows good agreement to the real flow and the filling phenomena in the die cavity. To give a boost to the economical efficiency of the thixoforming process and to ensure good forming results, a re-heating device coupled to die set was proposed and the initial billet temperature for the system was found by experimental results. This study presents an over-view of the application of numerical analysis for the simulation of a semi-solid metal forming process to reduce the lead time for the development of a manufacturing part in the industry field.