Possibilities of using vacuum casting process for manufacturing cast models of turbocharger impellers

Possibilities of producing cast models of turbocompressor impellers in silicon matrices by vacuum casting process are presented. Vacuum casting process enables producing cast models of impellers for precision casting. A standard model for silicon matrix making is a prototype produced with stereo lithography technique. The advantage of stereo lithographic model is its easy machinability that enables higher quality of impeller model surface. Silicon matrices enable casting of prototype models from foundry plastics, such as: casting wax, polyurethanes, polyester and epoxy resins. Properties of the plastic material used determine the shape of die parting. Because of its low strength, casting wax enforces die parting into a larger number of elements, thus enabling to pull it out without damage. The prototypes made from casting resins require considerably fewer parting surfaces. Silicon matrices enable to manufacture from several to several dozen cast patterns of prototype turbocharger impellers. The basic advantage of vacuum casting process is the shortening of prototype making time and cost, compared to traditional methods. The silicon matrixes permit casting and low-pressure injections of plastics. Some plastics may be used for producing foundry patterns for various metal alloy casting processes.