2024 aluminium alloy is an aluminium alloy, with copper as the primary alloying element. It is used in applications requiring high strength-to-weight ratio, as well as good fatigue resistance. It is weldable only through friction welding, and has average machinability. Due to poor corrosion resistance, it is often clad with aluminium or Al-1Zn for protection, although this may reduce the fatigue strength.[1][2] In older systems of terminology, 2XXX series alloys were known as duralumin, and this alloy was named 24ST.
2024 is commonly extruded, and also available in alclad sheet and plate forms. It is not commonly forged (the related 2014 aluminium alloy is, though).[3]
ALCOA
was invoked but never defined (see the help page).