Hydrostatic extrusion of wires

Abstract

Although hydrostatic extrusion has many advantages, the process is still not commonly adopted in industry, partly due to lack of information and transfer of technical knowledge. Small-diameter wires are in increasing demand, but the production of such wires by the drawing process suffers from the tensile-failure phenomenon: wire breakages are common and many drawing passes are required. In constrast to the drawing process, hydrostatic extrusion provides a much higher reduction per pass, as the tensile-failure phenomenon is absent. In this paper, the findings of a study of the effects of die included-angle, extrusion ratio and draw stress on the extrusion break-through pressure of 99.5% pure aluminium wires are presented. The effects of different hydrostatic mediums on the process are discussed also.