Flow features and industrial applications of TSE rheoextrusion process

Abstract

This paper presents an overview of diverse extrusion techniques and, in particular, a focused discussion about the rheoextrusion pro- cess for semi-solid casting (a novel casting pro- cess for the fabrication of high quality metals). The review reveals a wealth of interesting rhe- ological and microstructural features, illustrating qualitative and quantitative data. The analysis is supported by relevant numerical results and ex- amples. It is shown how numerical studies can lead to significant insights into these processes by providing more detailed information on the fundamental mechanisms of morphology devel- opment (during phase change) and profile form- ing. The die filling and solidification behaviours within extrusion dies are simulated numerically. The extrusion forming process is also investigated and compared with experimental results. The nu- merical results show that the profiles of velocity and solidified front of semi-solid metals (SSM) within the die will influence the final microstruc- ture of casts, both in the interior and on the sur- face. Finally, an industrial application employing a special patented concept design is presented and analysed. Keyword: Rheoextrusion, semi-solid metals, die filling, metal forming, solidification