Introduction of Friction Stir Welding on primary structures of aircrafts

Friction Stir Welding is a solid phase joining process commonly used in aluminium industry.  Contrary to fusion welding process, FSW allows welding of 7xxx and 2xxx alloys, frequently used in aeronautic industries. Repeatability, low cost and high mechanical properties are the main qualities which make FSW a good candidate to replace splice assemblies on aircraft structures. Fastening assembly removal should enable substantial weight and cost saving.

STELIA Aerospace is French aerostructures leader and major worldwide player for design and production of equipped fuselages. STELIA Aerospace produces every year more than 650 noses and fuselage sections and 6 million elementary parts and panels. For 6 years, STELIA Aerospace leads research programs dedicated to FSW technology:

• A first research program, dedicated to the welding of nose fuselage structure, leads to the manufacturing of two scale 1:1 demonstrators. This area is characterized by a double curvatures shape and is submitted to impacts (bird, hail…). Two welding configurations are considered: butt joint welding in order to replace the longitudinal lower unit splicing and lap joint welding to assembly stringers on upper cap panels.

• For one year, a second research program has focused on butt-joint configuration for fuselage application. The aim is to develop an industrial process which takes account of corrosion, certicicability and cost aspects.  A six meters long demonstrator in AA2024 clad aluminium is going to be welded and characterized.

• A last research program is beginning. The target is to save cost on AA2050 aluminium parts by reducing the “buy to fly” ratio. A blank welding for landing box application will be realized and characterized.