Friction Stir Welding ( FSW ) and near net spin forming of FSW aluminumn blanks were investigated for large - scale pressure vessel applications . With a specific focus on very thin gage 2xxx and 7xxx aluminum alloys , the program concentrated on the following : the criteria used for material selection , a potential manufacturing flow , and the effectiveness and associated risks of near net spin forming . Discussion will include the mechanical properties of the friction stir welds and the parent material from before and after the spin forming process . This effort was performed under a NASA Space Exploration initiative focused on increasing the affordability , reliability and performance of pressure vessels larger than 10 ft . diameter .