Application of mashy state extrusion

Abstract

Mashy state extrusion, a new metal forming process, is proposed and investigated. In the process, mashy billets, including solid and liquid components, are extruded into bars, wires, and tubes. The process is applied not only to aluminum alloys and copper alloys, but also to metal-ceramic composites. Through the study, the extrusion conditions necessary to manufacture sound products and mechanical properties of extruded bars, wires, and tubes are investigated. It is found that the extrusion force or pressure for mashy state extrusion is distinctively lower than that for the conventional hot extrusion; therefore, a high extrusion ratio is easily attainable. The mechanical properties of products and their internal structures are satisfactory when the appropriate solid fraction of billet, reduction in area, and cooling conditions at die are employed. Through the investigation, it becomes clear that mashy state extrusion is a metal forming process with very good potential and is effective to manufacture various metal-metal and metal-ceramic composite products.