USE OF HIGH-PERFORMANCE MATERIALS BY SMART ASSEMBLY AND FORMING TECHNIQUES

Targeting a continuous decrease of environmental footprint, future aircraft generations should provide a high performance level with a low level of CO2 emission and a good recyclability. For airframes, this translates into a significant mass saving, an easier maintenance with longer inspection intervals and a decreased sensitivity to corrosion. Such an improvement can be achieved by enhanced materials and integration of smart forming and assembly techniques.

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 using thinner gauge, higher performance materials. Weight savings are 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 developing dedicated materials.

As for Friction Stir Welded structures, nearer net shape billets to reduce the buy-to-fly ratio and to increase the performance thanks to thinner gauge, rollforming for plates is an interesting enabler to increase the cost-performance balance of monolithic structures.

Thin gauge fuselage skin panels, in particular the aircraft nose fuselage contains complex spherical shapes, also require excellent forming capabilities to allow one step stretchforming without any intermediate solutionizing treatments. For sheet material, the Friction Stir Welding process is applied to further increase performance by decreasing the number of rivets.

Constellium, and Airbus Atlantic have been collaborating for many years to increase the maturity level of the above-mentioned technologies. Examples of various structural parts and 1:1 demonstrators formed and assembled with appropriate material choices of advanced alloys will be shown. The measurement of the carbon footprint by using life cycle analysis tools will complete the overview, confirming the excellent environmental performance of the metal technologies selected.