Deformation pattern,forces and process limits in combined radial and backward can extrusion

As a new method for a combined process in cold extrusion a combination of radial extrusion and backward can extrusion is presented. The investigations show an important influence of the tool geometry on the material flow. Control of the material flow is possible by little variation of gap height or die radius. According to the described mechanism an equilibrium between can and flange forming exists for a suitable tool geometry. Measurements of the hardness showed a more homogenious distribution as for simple radially extruded workpieces. Low loads, as well as good geometric properties are giving this combined extrusion process a good chance to become an alternative to other cold forming processes.