2xxx Aluminum Alloys: 2024 Aluminum Sheet

2xxx aluminum alloys belong to the Al-Cu-Mg alloy, which is called high-strength hard aluminum and is the most widely used structural aluminum alloy. The tensile strength of 2xx series aluminum alloy is 400~500 MPa, which is lower than the room temperature strength of 7xxx series aluminum alloy, but its heat resistance, fatigue characteristics, especially fatigue crack propagation resistance are better than those of 7xxx series aluminum alloy.

2000 series aluminum alloys have higher strength, and the alloy strength of 2xxx grades can compete with steel. However, due to differences in copper content, the strength and corrosion resistance of this series vary within a wide range to meet different needs.

Among them, the corrosion resistance of alloys with lower copper content is close to that of rust-proof aluminum; the strength of alloys with higher copper content is close to that of hard aluminum, which is actually equivalent to increasing the silicon content on the basis of hard aluminum.

Among the 2000 series aluminum alloys, the 2024 alloy invented in 1939 is the more commonly used one. 2024 alloy has brought huge changes to the structure and performance of aircraft, and also laid the foundation for the development of 2000 aluminum alloys.

2024 has a density of 2.78 g/cm 3 (0.1 lb/in 3 ), a conductivity of 30% IACS, and a Young's modulus of 73 GPa (10.6 Msi) in all states at 500 °C (932 °F). The composition of 2024 aluminum alloy roughly includes 4.3-4.5% copper, 0.5-0.6% manganese, 1.3-1.5% magnesium and less than 0.5% silicon, zinc, nickel, chromium, lead and bismuth.

2024 aluminum sheet has high strength and certain heat resistance, and can be used as working parts below 150℃. At temperatures above 125°C, the strength of 2024 alloy is higher than that of 7075 aluminum plate. The formability is relatively good in the hot state, annealed and newly quenched states, and the heat treatment strengthening effect is significant, but the heat treatment process requirements are strict.

The common tempers of 2024 aluminum is T3, T351 and T4. 2024 t351 aluminum has high plasticity, fatigue life, fracture toughness and resistance to fatigue crack growth, but poor corrosion resistance. This alloy thick plate is mainly used in fuselages, wings, shear floors and webs, and other structural parts with high strength requirements.