2124 Aluminum Alloy Plate


2124 aluminum alloy is an American standard aluminum alloy, equivalent to Chinese GB grade 2A12. The main alloying element of 2124 aluminum alloy is mainly copper, which is called Al-Cu-Mg hard aluminum alloy, which has high strength and good cutting performance. But the corrosion resistance is poor. It is widely used in aircraft structures (skins, skeletons, rib beams, bulkheads, etc.), rivets, missile components, truck hubs, propeller components and various other structural parts. 


2124 aluminum alloy has high strength and certain heat resistance, and can be used as working parts below 150°C. At temperatures higher than 125°C, the strength of 2124 alloy is higher than that of 7075 alloy. In hot state, annealing and new quenching state, the forming performance is better, and the heat treatment strengthening effect is obvious, but the heat treatment process is strict. The corrosion resistance is poor, but it can be effectively protected by covering with pure aluminum; it is easy to produce cracks during welding, but it can be welded or riveted by special technology. It is widely used in aircraft structures, rivets, truck wheels, propeller components and various other structural parts.


Chemical Composition:

ChemicalWeight %
Chromium0.1 max
Copper3.8 - 4.9
Iron0.3 max
Magnesium1.2 - 1.8
Manganese0.3 - 0.9
Remainder Each0.05 max
Remainder Total0.15 max
Silicon0.2 max
Titanium0.15 max
Titanium + Zinc0.2 max
Zinc0.25 max


Physical Properties:


Density2.6-2.8 g/cm30.0939-0.1011 lb/in3
Melting point510°C950°F


Mechanical Properties:


Elastic modulus70-80 GPa10152-11603 ksi
Poisson's ratio0.330.33


Thermal Properties:


T (ºC)Treatment
Thermal conductivity191 (W/mK)25O



The alloy is machinable by conventional means. Optimum machinability is with the alloy in the T 851 ( precipitation heat treated ) condition.



Formability of this alloy, which is supplied in plate form, is limited. Severe cold working should be avoided and as with Machinability the optimum condition for forming is the T 851 temper.



The alloy has a problem with crack sensitivity during welding. Resistance welding may be successfully used with proper weld procedure. Gas welding and arc welding should be avoided.


Heat Treatment

The alloy may be solution annealed at 920 F followed by water quench. Precipitation hardening is done at 375 F for 12 hours and air cooling - this produces the T 851 temper.



No specific data. However the alloy is forgeable.


Hot Working

No data. It may be advisable to avoid hot working because of the alloy tendency to cracking from heat input.


Cold Working

Cold working may be done, but the extent of cold working is limited as compared to other aluminum alloys.



Annealing is done at 775 F for 2 to 3 hours followed by cooling at 50 F per hour to 500 F. Then air cool.



Aging, or precipitation hardening in fact, is done at 375 F for a time of approximately 12 hours followed by air cooling.



Not applicable to this alloy.



Hardening, or strengthening, is accomplished by means of precipitation hardening at 375 F for 12 hours followed by air cooling.


Other Physical Props

Electrical conductivity 38% of copper.



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