Abstract: The present invention is directed to friction stir welding, and in particular to apparatuses, methods, and systems using friction stir welding to join one or more components comprising an aluminum 2xxx alloy with one or more components comprising an aluminum 7xxx alloy. The aluminum 2xxx alloy may be in the form of a filler insert, for example a sheet or strip, between two larger aluminum 7xxx alloy components, or the aluminum 2xxx alloy may be in the form of a larger component welded directly to an aluminum 7xxx alloy component of comparable size. Weldments according to the present invention have improved resistance to stress corrosion cracking without the need for post-weld artificial aging and are useful in many applications, for example in construction of spacecraft parts.

Abstract: Method for storing a waste gas mixture comprised of nitrogen, oxygen, carbon dioxide, and inert gases, the gas mixture containing corrosive contaminants including inorganic acids and bases and organic solvents, and derived from space station operations. The gas mixture is stored under pressure in a vessel formed of a filament wound composite overwrap on a metal liner, the metal liner being pre-stressed in compression by the overwrap, thereby avoiding any tensile stress in the liner, and preventing stress corrosion cracking of the liner during gas mixture storage.