Microstructure and properties of composite-extruded aluminium alloys.

Extrusion facilitates the flexible production of lightweight space structures. The stiffness and the strength hereby result from the material that is used, usually aluminium or magnesium, as well as from the geometry of the profile. The efficiency of the space structures can be increased directly during the extrusion process by embedding reinforcement elements which have a high strength and a high stiffness and without a change of the geometry of the profile. This publication gives an overview of the material combinations which are processible during composite extrusion, the evolving microstructures and the mechanical properties of the composites. The main focus is on the interface between matrix and reinforcing element, which is investigated by metallographic examinations and push-out tests. The failure behaviour of the composites is analyzed by means of static tension tests and cyclic tension-compression tests. At the current state of the art specific strengths can be increased up to 80%.