According to different types of process, semi-solidis usually divided into two kinds: rheological casting and thixotropic casting. Although rheological is more simple with less energy consumption and lower cost, it is difficult to maintain and transport semi-solid metal slurry during rheological casting process which lead to less application of rheological casting technology.
At present, the industrial application of semi-solid cast metal is mainly refers to thixotropic casting. As the first item in the thixotropic casting is to produce semi-solid metal blank which cost higher with large consumption of secondary heating energy and complicated process. So there are a few metal materials with thixotropic property. Therefore, the application of semi-solid cast metal is limited in the industrial production.
In recent years, the experts around the world apply plastic injection molding principle to semi-solid cast metal. Then they form two kinds of new processes which are the rheological injection molding (Rheomoulding) and thixotropic injection molding (Thixomoulding). They integrate the preparation of semi-solid metal slurry, transportation and forming process into an organic whole. Thus the new technology has solved the difficulties about preservation and transportation of the semi-solid metal during the cast metal.