Novel processing method for metallic materials

The feasibility of a new process that integrates all thermal and mechanical operations involved in the production of wrought metal strips was examined. The process involves continuous extrusion on a screw type extruder. A Pb-2.0% Sb alloy was used as a model material. Continuous strips of metal could be produced when back leakage of the melt was limited. For this, the clearance between screw and extruder barrel had to be kept small and the viscosity of the partially solidified alloy had to be kept high by limiting the rotational speed and by maintaining an experimentally determined temperature profile along the extruder barrel. Intense shearing of the material resulted in rapid homogenization and in dynamic recrystallization of the metallic matrix.