2195 aluminium alloy is an alloy in the wrought aluminium-copper family (2000 or 2xxx series). It is one of the Weldalite family of Aluminium–lithium alloys.[1] It is one of the most complex grades in the 2000 series, with at least 91.9% aluminium by weight. 2195 aluminium can be alternately referred to by the UNS designation A92195.
Like most other aluminium-copper alloys, 2195 is a high-strength alloy, with bad workability, and poor corrosion resistance. Being highly alloyed, it tends to fall on the higher strength and lower corrosion resistance side. As a wrought alloy, it is not used in casting. It can be welded, particularly by friction stir welding, and is fracture resistant at cryogenic temperatures.[1]
The high strength to weight ratio of this alloy has resulted in its aerospace applications such as the Space Shuttle Super Lightweight external tank.[1] It is 30 % stronger and 5 % less dense than the 2219 alloy used in the original Space Shuttle external tank.[1]
2195 is used for the propellant tanks of the Falcon 9 Full Thrust orbital launcher,[2][3] and for the new ULA Vulcan first stage.[citation needed]