Each alloy contains specific percentages of alloying elements that give the base aluminum certain beneficial qualities.In 2024 aluminum alloy, these element percentages are nominally 4.4% copper, 1.5% magnesium, and 0.6% manganese.This breakdown explains why 2024 aluminum is known for its high strength, as copper, magnesium, and manganese greatly increase the strength of aluminum alloys.However, this power has a downside.The high proportion of copper in 2024 aluminum greatly reduces its corrosion resistance.There are usually trace amounts of impurity elements (silicon, iron, zinc, titanium, etc.), but these are only purposefully given tolerances at the buyer’s request.Its density is 2.77g/cm3 (0.100 lb/in3), slightly higher than pure aluminum (2.7g/cm3, 0.098 lb/in3).2024 aluminum is very easy to machine and has good machinability, allowing it to be cut and extruded when required.
As mentioned, bare 2024 aluminum alloys corrode more easily than most other aluminum alloys.Manufacturers get around this by coating these susceptible alloys with a layer of corrosion-resistant metal (called “galvanizing” or “cladding”).This coating is sometimes high-purity aluminum or even another alloy, and is most popular in clad metal sheets, where the virgin alloy can be sandwiched between the cladding layers.Clad aluminum is so popular that a range of AlClad products have been developed and widely used to provide the best of both worlds for weakly corrosive alloys such as 2024.This development makes 2024 aluminum particularly useful because its strength can be achieved where bare alloys would normally degrade.
Some aluminum alloys, such as the 2xxx, 6xxx, and 7xxx series, can be strengthened using a process called heat treatment.The process involves heating the alloy to a specific temperature to mix or “homogenize” the alloying elements into the base metal, then quenching in solution to lock the elements in place.This step is called “solution heat treatment”.These elements are unstable, and when the workpiece cools, they 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 by interacting with the aluminum microstructure, a process known as “aging.”Understanding the solution heat treatment and aging process is important because 2024 aluminum comes in many types and is given designations such as 2024-T4, 2024-T59, 2024-T6, etc., depending on how these steps are performed.
Type 2024 aluminum’s best strength qualities come not only from its composition, but also from its heat-treating process.There are many different procedures or “tempering” of aluminum (given the designation -Tx, where x is a 1 to 5 digit long number), and although they are the same alloy, they all have their own unique properties.The first digit after the “T” indicates the basic heat treatment method, and the optional second to fifth digits indicate the specific manufacturing quality.For example, in a 2024-T42 temper, a “4″ indicates that the alloy is solution heat treated and naturally aged, but a “2″ indicates that the metal must be heat treated by the buyer.The system can get confusing, so in this article we will only show strength values for a more basic tempered 2024-T4 aluminum.
There are certain mechanical properties that can be used to specify aluminum alloys.For alloys such as 2024 aluminum, some important measurements are ultimate strength, yield strength, shear strength, fatigue strength, and elastic and shear moduli.These values will give an idea about the machinability, strength and potential uses of the material and are summarized in Table 1 below.
Yield strength and ultimate strength are the maximum stresses that cause non-permanent and permanent deformation of alloy specimens, respectively.For a more in-depth discussion of these values, feel free to visit our article on 7075 Aluminum Alloy.They are important when alloys are used in static applications where permanent deformation should not occur, such as in buildings or safety equipment.2024 aluminum has impressive ultimate and yield strengths of 469 MPa (68,000 psi) and 324 MPa (47,000 psi), making it attractive for high-strength structural materials such as aluminum tubing.
Finally, elastic modulus and shear modulus are parameters that show how “elastic” a given material is to deform.They give a good idea of the resistance of the material to permanent deformation.The 2024 aluminum alloy has an elastic modulus of 73.1 GPa (10,600 ksi) and a shear modulus of 28 GPa (4,060 ksi), which is even higher than other high-strength aircraft alloys such as 7075 aluminum.
Type 2024 aluminum has excellent machinability, good workability, high strength, and can be clad to resist corrosion, making it an excellent choice for aircraft and vehicle applications.
Post time: Jun-30-2022