AL2024 is an aluminium alloy, with copper as the primary alloying element (respective elemental percentages are 4.4% Cu, 1.5% Mg, and 0.6% Mn, nominally). It is used in applications requiring high strength to weight ratio, as well as good fatigue resistance, weldablility and average machinability. Its density is 2.77g/cm3 (0.100 lb/in3), which is slightly higher than pure aluminum (2.7g/cm3, 0.098 lb/in3). 2024 aluminum alloy is machined very easily and has decent workability, allowing it to be both cut and extruded if need be. The high percentage of copper in 2024 aluminum greatly reduces its resistance to corrosion and therefore it is more prone to corrosion than most other aluminum alloys. For this reason a coating with a layer of corrosion-resistant metal (referred to as “galvanizing” or “cladding”) is often used. This coat is sometimes high purity aluminum or even another alloy, specified as CLAD or ALCLAD, and is most popular in clad sheet metal where the original alloy can be sandwiched between the cladding layers. Clad aluminum is so popular that a series of AlCLAD products have been developed and are widely used to give corrosion-weak alloys like 2024 the best of both worlds. This development makes 2024 aluminum especially useful because its strength can be implemented where the bare alloy would normally degrade.
Like some of the other aluminum alloys, AL2024 comes without heat treatment (O Temper) or with heat treatment for increased strength. The heat-treatment process involves heating the alloy to a specific temperature to allow the alloying elements to mix, or “homogenize” into the base metal, and then quenching it in a solution to lock these elements in place. This step is known as “solution heat treating.” These elements are unstable, and when the piece cools, they will precipitate out of the aluminum “solution” as compounds (for example, copper atoms will precipitate out as Al2Cu). These compounds increase the overall strength of the alloy via interactions with the aluminum’s microstructure, and this process is known as “aging.” The processes of solution heat-treating and aging are important to know, because there are many types (tempers) of 2024 aluminum designated by the letter "T" and numerical digits (e.g. 2024-T4, 2024-T6, etc.). The first digit following the “T” indicates the basic heat treatment method and optional second-to-fifth digits indicate specific manufacturing qualities. For example, in the 2024-T42 temper, the “4” indicates that the alloy is strengthened with solution heat-treating and natural aging, but the “2” indicates that the buyer must heat-treat the metal themselves.
In selecting an aluminum alloy, its mechanical properties should be carefully considered. For an alloy such as 2024 aluminum, some important measures are ultimate strength, yield strength, shear strength, fatigue strength, as well as the modulus of elasticity and shear modulus. These values provide important information on the workability, strength, and potential uses of the alloy. The yield and ultimate strengths are the maximum amount of stress that will non-permanently and permanently deform a specimen of alloy, respectively. 2024 aluminum has impressively large ultimate and yield strengths at 469MPa (68,000 psi) and 324 MPa (47,000 psi), which makes it attractive for high-strength structural materials such as aluminum tubing.
Shear and fatigue strength are measures of a material’s resistance to specific stressors. For shear strength, this means the resistance to shearing stresses, also known as “cutting” stresses. The shear strength of 2024 aluminum is 283 MPa (41,000 psi), which is moderately strong while still allowing it to be cut from common bar stock. The fatigue strength is the measure of how resistant a material is to breaking under such fatigue. It is a valuable measure for alloys that appear in aerospace applications such as 2024 aluminum. Aircraft experience periodic stresses (such as from takeoff, landing, etc.), may not deform the alloy initially but, when repeatedly exposed, the alloy may weaken microscopically and then eventually macroscopically. The fatigue strength for 2024 aluminum is 138 MPa (20,000 psi), calculated with 500,000,000 cycles of loading under the yield point.
Finally, the modulus of elasticity and shear modulus are parameters that display how “resilient” a given material is to deform. They give a good idea as to a material’s resistance to permanent deformation. For 2024 aluminum alloy, the modulus of elasticity is 73.1 GPa (10,600 ksi), and the shear modulus is 28 GPa (4,060 ksi), which is even greater than that of other high strength aircraft alloys such as 7075 aluminum.
AL2024 bars/rods are offered as part of our own branded (AVIATIONEU NEW ERA) product lines along with those from other aluminum and steel alloys (e.g. AL5052, AL6061, AL7050, AL7075, ST4130, ST4140 etc.). Sourced from quality producers, they are available in different shapes, (such as round, hexagonal, square and others), tempers, specifications, diameters/thicknesses, pre-cut lengths or cut-to-oder and in different units of sale, (pieces or tons) depending on the wanted order quantity and requirements. Like other AL2024 products these bars/rods can be used in an extensive list of applications in aerospace, automotive and many other industrial sectors.
For additional information, please refer to our Brief Guide on Aluminum Grades & Temper Designations, the individual product presentations or contact us.
