Cost efficient and high performing structural parts using enhanced assembling techniques as Friction Stir or Linear Friction Welding

Over the last several years, structural component demonstrations using the Friction Stir Welding (FSW) process have brought the technology closer to the manufacturing plants. Several collaborative projects with aircraft manufacturers and Tier 1’s have shown that the technology is reliable, fast and cost efficient. Assembly configurations led to high performance cost efficient tailored components. Applications as underfloor beams, ribs, wing skins, inner fuselage components were developed and tested at full scale in order to prepare the first step for future industrialization.

In parallel, improvements of the process itself led to higher welding depth - up to 35 mm using conventional machines - in order to be able to use the advantages of FSW for a larger number of high gage applications. These enhancements have only been possible due to concomitant optimization of the welding tool and the welding parameters.

In parallel, Linear Friction Welding (LFW), which has been used for more than 10 years in the aircraft engine industry, was introduced for aluminium structural parts and was found to be particularly complementary with Friction Stir Welding. LFW is well adapted for complex shapes and can deliver high precision add-ons to plate while improving tremendously the buy to fly ratio. Therefore, this process was tested and fully characterized at Constellium in order to assess its behavior to be used in low cost/high performance structures.

Examples including key characterizations of the welded products as mechanical or corrosion properties and quality checks done by non-destructive testing will be discussed.

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