Extrusion of sections by immuring technique

Abstract

To improve homogeneity in extrusion of sections, extrusion of aluminium by an immuring technique using lead has been studied. In steady state extrusion, the immuring material is trapped in a triangular region surrounded by a die wall, a container wall and a deforming billet, and behaves like a part of an extrusion die. The flow pattern obtained by this technique is far more homogeneous than that by using the conventional technique, and also the extrusion load is 20% lower than that by the conventional technique. The profile of the withdrawn billet can be regarded as the optimum die profile required. The profile determined in this way is very close to the theoretical optimum profile. This experimental technique can also be used to determine the die profile for the near homogeneous internal deformation.