ALUMINIUMWERK UNNA AG

Seamless aluminium tubes can be ordered in all commercially available aluminium alloys in addition to high strength aluminium alloys which are required for more demanding applications. ALUnna has a number of extrusion presses equipped with mandrel piercing capability. This allows us to extrude a large range of extruded tubular dimensions from a number of different billet diameters. The size range for seamless extruded tubes ranges from 17 mm to 300 mm in diameter.

Aluminiumwerk Unna AG is specialised in the production of Aluminium tubes. The Aluminium tubes are extruded on site using two possible methods. These are either Seamless extrusion or Porthole extrusion. It is quite simple to distinguish between the two extrusion methods. In seamless extrusion, a mandrel is positioned and fixed inside the extrusion die, creating the inner contour of the tube. In porthole extrusion, the mandrel is fixed and is supported by a number of integral bridges affixed to the outer portion of the extrusion die.

In the aluminium industry, the porthole extrusion process is the standard method for the production of extruded tubes and profiles. The process is limited to a number of aluminium alloys. However, most of the commercially available medium strength aluminium alloys such as EN AW-6060 or EN AW-6082 can be extruded by porthole extrusion.

Depending on the application, tubes may require subsequent drawing following the extrusion process. Examples of this are: a requirement for a high degree of dimensional control and/or the need for tight tolerances, where the final outside diameter and/or wall thickness of the extruded tubes can only be achieved by subsequent cold drawing, where the final mechanical properties for non-heat treatable alloys are to be achieved by strain hardening (drawing) or where special requirements exist for the microstructure of the tubes.