Investigation into the improvement of welding strength in three-dimensional extrusion of tubes using porthole dies

In this work, a modified porthole die for tube extrusion has been developed in order to obtain larger welding pressure than that of conventional porthole dies, and the effect of the improved porthole die on welding pressure has been investigated by performing the finite element analysis on aluminum tube extrusion. The comparison of welding strength of tubes extruded by the modified porthole die with that of tubes made by a conventional porthole die on an expanding test has shown that the tubes from the modified die have been improved in welding strength.