FEM supported semi-solid high pressure die casting process optimization based on rheological properties by isothermal compression tests at thixo temperatures extracted

Rheological properties of aluminum are among others required in FEM supported calculations of thixo-forming processes. In the present paper, an analytical-experimental method is introduced to acquire such properties as a function of temperature and flow velocity. This method is based on isothermal compressive tests' results evaluation at various temperatures. The determined rheological properties are used to optimize thixo-forming process parameters and ensure die filling during high pressure semi-solid casting, without air entrapments. Considering the developed temperature field, hot spots can be avoided by employing cooling systems at proper positions. An application example is demonstrated in the case of high pressure die casting of an aluminum car wheel. (C) 2012 Elsevier B.V. All rights reserved.