Experimental investigation of semi-solid casting and die design by thermal fluid-solidification analysis

In the semi-solid casting process, various defects are strongly affected by the die shape rather than by other fabrication parameters because the semi-solid materials have to travel a relatively long distance to fill the die cavity through a gate during the filling time. To obtain high quality component with the semi-solid casting process, it is important to obtain a homogeneous distribution of solid particles without liquid segregation until the die is completely filled. A gate shape with a different runner system was investigated to produce a near-net-shape compressor component called a cylinder block. Die design by computer simulation has some advantages compared with the conventional process that is performed by the designer’s experiences and trial-and-error. The experiment of semi-solid casting was performed with the conventional die design concept. Various defect shapes were found on the surface of the semi-solid cylinder block parts. Evaluation of die gate system to obtain part without defects was realized by computer simulation. MAGMAsoft performed the die filling and solidification analysis of the semi-solid casting process with the add-on module ‘thixo’. A designed new gating system considering thermal fluid and solidification phenomena was suggested by the filling simulation.