2195 aluminium alloy
2195 aluminium alloy is an alloy in the wrought aluminium-copper family (2000 or 2xxx series). It is one of the most complex grades in the 2000 series, with at least 91.9% aluminium by weight. 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] It is one of the Weldalite family of Aluminium–lithium alloys.[1]
2195 aluminium can be alternately referred to by the UNS designation A92195.
It is 30 % stronger and 5 % less dense than the 2219 alloy used in the original Space Shuttle external tank.[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]
2195 is used for the propellant tanks of the Falcon 9 Full Thrust orbital launcher,[2] and for the new ULA Vulcan first stage.
Chemical Composition
The alloy composition of 2195 aluminium is:[3][4]
- Aluminium: 91.9 to 94.9%
- Copper: 3.7 to 4.3%
- Lithium: 0.8 to 1.2%
- Magnesium: 0.25 to 0.8%
- Silver: 0.25 to 0.6%
- Zirconium: 0.08 to 0.16%
- Iron: 0.15% max
- Silicon: 0.12% max
- Titanium: 0.1% max
- Zinc: 0.25% max
- Residuals: 0.15% max
References
- ^ a b c d Super Lightweight External Tank, NASA, retrieved 12 Dec 2013.
- ^ How Light Metals Help SpaceX Land Falcon 9 Rockets... April 2019
- ^ Precipitation of T1 and θ0 Phase in Al-4Cu-1Li-0.25Mn During Age Hardening: Microstructural Investigation and Phase-Field Simulation
- ^ 2195 Aluminum Composition Spec