Aluminum alloys are one of the most widely used materials in aviation field. hey have good mechanical properties and process characteristics, and are characterized by high strength, light weight, and good toughness. They are one of the most important members of the civil aircraft structural material family.
The main features of Al alloy 2024 are large-scale and integrated, thin-walled and lightweight, precise cross-sectional dimensions and geometric tolerances, and uniform and high-quality structural properties. Aluminum alloys used in aerospace are mainly high-strength aluminum alloys, heat-resistant aluminum alloys, and corrosion-resistant aluminum alloys. High-strength aluminum alloys are mainly used in aircraft fuselage components, engine nacelles, seats, control systems, etc.
Al alloy 2024 is a typical hard aluminum alloy in the aluminum-copper-magnesium system. It contains 4.5% copper, 0.6% manganese and 1.5% magnesium. Its composition is reasonable and its overall performance is good. It is the most heavily used among the duraluminum alloys. 2024 aluminum alloy is commonly used in T3 and T4 tempers, which have high plasticity, fatigue life, fracture toughness and resistance to fatigue crack growth, but poor corrosion resistance.
2024 T3 aluminum not only has high strength, but also has excellent fatigue resistance. Welding is generally not recommended. Typical uses for 2024-T3 Alclad aluminum sheet are fuselage and wing skins, roofs, aircraft structures, and repair and restoration. Its ultimate strength is 62,000 PSI and shear strength is 40,000 PSI.
Aircraft manufacturers use high-strength alloys (mainly Alloy 7075) to strengthen aluminum aircraft structures. Aluminum alloy 7075 has copper (1.6%), magnesium (2.5%) and zinc (5.6%) for ultimate strength, but the copper content makes it very difficult to weld. 7075 aluminum has the best machining performance and can achieve very good results. The ultimate strength is 33000 PSI(-0) and 82000 PSI(-T6), and the shear strength is 22000 PSI(-0) and 49000 PSI(-T6).
7075 aluminum sheet’s common tempers are T6, T73, T76 and T74. 7075 t6 alloy has the highest strength, low fracture toughness, and is sensitive to stress corrosion cracking. It is generally not recommended for use in low temperature applications. The thermal conductivity of the material is related to its state. At 25℃, the thermal conductivity of the 7075-t6 is 124W/(m·℃), while that of the T73 material is higher, 156W/(m·℃). The specific heat capacity of 7075-T6 alloy (at 25℃) is 796J/(kg·℃).
Original source: https://www.aircraft-aluminium-sheet.com/a/aviation-aluminum-alloy-2024-7075.html
