Pressing Velocity Control Considering Liquid Temperature Change in Press Casting

To newly create the sand casting method to drastically improve productivity and casting quality, author's group has actively developed advanced control technology in foundry. In high-speed filling of the press casting process using greensand mold, some defects are caused by increased pressure of molten metal, such as metal penetration which the solidified molten metal flows into between the sand particles. Hence, we will propose controlling the pressing velocity in order to suppress increasing pressure. Considering pressure constraint for a defect-free product, control velocity pattern is then derived by using proposed mathematical model of molten metal's pressure in the mold. The simple pressure model is derived by considering the wall shearing stress depended on molten metal's temperature to accurately represent actual pressure behavior during pressing. Analytical results for the liquid temperature decrease during filling and its consideration for the pressing control are mentioned in this paper. The effectiveness of control result using the model is checked by CFD: Computational Fluid Dynamics simulations. In near future, experimental examinations will be carried out by practically using water and molten metal.