AIRWARE® FSW TAILORED-WELDED-BLANK FOR HIGH PERFORMANCE AND COST-EFFICIENT STIFFENED PANEL FOR AEROSPACE APPLICATIONS

Friction Stir Welding has been studied extensively by major players of the aeronautics industry. This robust welding process can improve airframe performance by building up thick gauge structures by thinner gauge materials. Weight savings is possible due to the “T-joint” welded configuration and the good mechanical behaviour of the welded joint. Cost savings can be achieved by reducing the machining time and the development of dedicated materials.

Constellium, and Airbus Atlantic have been collaborating for more than 5 years to propose a global and robust manufacturing sequence to join Airware^® (AA2050) stiffened panels. Mechanical and corrosion aspects have been extensively assessed, including other material characterization as fatigue and damage tolerance. Industrial aspects like tooling, Non-Destructive Testing and stress relief treatments have been studied. Results coming from various welded coupons and scale 1:1 prototypes were satisfactory and confirm the high potential of the technology for aero-structures manufacturing.

However, to ensure cost performances of the process, it is mandatory to minimize the influence of post milling distortions. Specific heat treatments, and manufacturing process optimisation could be considered as solutions to improve the robustness of this stiffened panel design.

To assess performances of process monitoring, a specific test program has been performed:

• Many scale 1:1 and scale 1:2 coupons have been welded, heat treated and machined in different industrial configuration.
• Different Airware^® materials have been characterized.
• Specific heat treatments have been studied, including numerical simulation.

The main results of these tests, the data analyses methods and the potential of specific heat treatment for our welding configuration will be presented and discussed.