©Bernulius/stock.adobe.com

Lightweight Garage #15 Friction Stir Welding @ Ariane 6

February 10, 2022
by Luca Wilhelmy

The Vehicle

In this garage is a vehicle that flies high. The Ariane 6 is the next stage of development after the Ariane 5 launcher. Like its predecessor, it should also be used to transport various types of satellites. Since each kilo of payload to be transported into orbit already costs more than 10,000 dollars, the long-term goal is to reduce launch costs.


©SkywalkerPL - Ariane 6, CC BY 3.0

The Technology

To reduce the weight and costs of Ariane 6 in the long term, a wide variety of technologies are being used. One of these technologies is friction stir welding. As the name suggests, the process is a type of welding. However, in contrast to conventional welding methods, the joining zone is heated less, a much smaller weld-affected zone is created, which has a positive effect on the mechanical properties. This is also reflected in the same material characteristics of the material and the weld influence zone. In addition, materials and material combinations can be welded that are otherwise not weldable. These advantages are used in the Ariane 6 to manufacture the hydrogen tanks. By switching from TIG welding to friction stir welding, the set-up time of more than three hours can be reduced considerably. In addition, friction stir welding does not require any filler materials for welding, which eliminates another cost factor.

The Lightweight Aspect

As already explained, the goal here is cost reduction. In addition, a weight reduction is achieved through the measures, which also has a positive effect on the cost development. Friction stir welding has already shown similar results in various applications. For example, the technology has already been used in vehicles such as the Ford GT (2004) or Mercedes SL (2012). Friction stir welding shows great advantages especially with thin sheet metals, unlike with conventional processes, the sheet thickness does not have to be increased. Due to the better mechanical properties compared to other welding technologies, the weak point "weld seam" can be evaluated differently and thus the component weight can be reduced.

©MT Aerospace AG, Friction stir welded hydrogen tank of Ariane 6

 

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