All kinds of aircraft aluminum alloy are used as the main structural material. Skins, beams, ribs, stringers, bulkheads, and landing gear on aircraft can all be made of aluminum alloys. The amount of aluminum used in the aircraft varies according to its purpose. The top two commonly used ones are 2024 and 7075 aluminium alloys.
7075 alloy is an aluminum-zinc-magnesium-copper series of high-strength deformed aluminum alloys that can be strengthened by heat treatment. It can be used to process all semi-finished products and structural parts. It is the most widely used high-strength aluminum alloy today, ranging from the front fuselage of the C919 large aircraft to the mobile phone shell.
Like other aluminium alloys, 7075 aluminum sheet has strong oxidation resistance.The resistance to general corrosion is comparable to 2024 alloy. The 7075-T6 alloy is extremely sensitive to stress corrosion cracking, especially in the transverse direction (ST), while the properties of T73 and T76 materials have been greatly improved. T73 material has the highest resistance to stress corrosion cracking, while T76 material not only has high strength, but also has high resistance to stress corrosion cracking and spalling corrosion.
2024 aluminum sheet is a typical hard aluminum alloy in the aluminum-copper-magnesium series, having good comprehensive performance. It is of high compressive strength and certain temperature resistance. After heat treatment, the 2024 aluminum alloy has undergone solid solution treatment to obtain relatively high compressive strength and ductility. It is generally used to produce skins, roof beams, bulkheads, and wings by plane.
2024 t3 aluminum sheet is one of the most widely used alloys in airframe construction. It has moderate yield strength, very good resistance to fatigue crack growth and good fracture toughness. 2024 aluminum alloy remains an important aircraft structural material due to its excellent damage tolerance and high resistance to fatigue crack growth under T3 aging conditions.
2024 aluminum alloy is often used in aircraft structural applications due to its high strength and fatigue resistance. It's stronger than the 6061, but less versatile. While 7075 is suitable for applications requiring high stress and strain resistance, 2024 has high cyclic fatigue resistance.