M. Schikorra, A.E. Tekkaya, M. Kleiner:
In: CIRP Annals - Manufacturing Technology, Volume 57, Issue 1, 2008, Pages 313-316


Embedding reinforcement or functional wires in extruded profiles offers the potential to increase mechanical properties as well as the field of application. With improved strength and stiffness and an integrated function as deformation sensor or data transmitter the weight of space frame structures can be reduced substantially. To comprehend the general conditions when embedding the reinforcement and functional elements during the extrusion process, experimental extrusion investigations have been carried out for the analysis of significant process and tool geometry parameters. Extrusion with porthole dies, i.e. by feeding the elements over bridges inside the die in the aluminum base material flow, was studied to manufacture continuous reinforced, thin-walled, and hollow profiles. Special care was taken to ensure an accurate positioning in the transient material flow to prevent a loss of functionality by insufficient covering and loss of positioning caused by the die geometry or unequal temperature distribution inside the die. Studies on different reinforcement wires and wire ropes based on high strength steel are presented, showing an increasing process stability when using solid wires. General process restrictions are analyzed and process guidelines are presented based on exemplary extrusions.