Friction Stir Welding of Titanium Space Propellant Tanks

Ti-6-4 is the curent baseline alloy for rocket/spacecraft propellant tanks. Theswe tanks are usulaly manufactured from forged feedstock and then welded using TIG and EB welding, before machining to size. The high cost of these tanks is primarily due to the extensive amount of machining that is required, and the cost of the initial forgings.

The 2 year collaborative project between TWI, the European Space Agency and Airbus Defence & Space UK investigated the use Ti-6-4 castings that were friction stir welded with a considerable reduction in post process machining. This presentation will discuss the development, characterisation and vaildation of the FSW process and tooling, the results of several mechanical property tests and will finish with the production of propellant tanks that were subject to further investigation.