What Are 2024T3 and 7075T6 Properties

2024 aluminum is an Al-Cu-Mg aluminum alloy with a density of 2.73 g/cm, which can be strengthened by heat treatment, and has moderate plasticity in the quenched and just quenched states. It has poor corrosion resistance, but it can be effectively protected by covering it with pure aluminum; it is prone to cracks during welding, but it can be welded or riveted by special processes.

The common tempers of 2024 aircraft aluminum alloy is T3, T4, T351 and T851. What are aluminium 2024 t3 properties? It has an ultimate strength of 62000 PSI and a shear strength of 40000 PSI. 2024 plate has an ultimate tensile strength of 400–430 MPa (58–62 ksi) and a yield strength of at least 270–280 MPa (39–40 ksi). It has an elongation of 10-15%.

2024 t3 aluminum sheet is considered an aircraft alloy due to its strength and also has excellent fatigue resistance. Soldering is generally not recommended. Typical uses for 2024-T3 aluminum sheet are fuselage and wing skins, roofs and aircraft structures.

7075 aluminum sheet is a cold-processed forging alloy with high strength, far superior to mild steel. Zinc is the main alloying element in 7075. Adding magnesium to an alloy containing 3%-7.5% zinc can form MgZn2 with a significant strengthening effect, making the heat treatment effect of the alloy far better than that of aluminum-zinc binary alloys. It is especially suitable for manufacturing aircraft structures and other high-stress structures that require high strength and corrosion resistance.

7075 aluminum has O, T6, T651 and T7 tempers. What are Al 7075 t6 properties? 7075 t6 has an ultimate tensile strength of 510–540 MPa (74,000–78,000 psi) and a yield strength of at least 430–480 MPa (63,000–69,000 psi). It has an elongation at failure of 5-11%.

7075 T6 is typically achieved by homogenizing casting 7075 at 450°C for several hours, quenching and then aging at 120°C for 24 hours. This produces the peak strength of the 7075 alloy. The strength comes mainly from finely dispersed eta and eta’ precipitates within the grains and along the grain boundaries.

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Aluminum 7075 Material Properties

7075 aluminum sheet is a commonly used grade in the 7xxx aluminum alloys. Zinc is its main alloying element. The addition of magnesium to the alloy containing 3%-7.5% zinc can form MgZn2 with a significant strengthening effect, so that the heat treatment effect of 7075 aluminum is far better than that of the aluminum-zinc binary alloy.

Aluminum plate 7075 is used to manufacture a variety of structural parts, especially aerospace structural parts. It is the most widely used high-strength aluminum alloy today, ranging from the front fuselage truss of the C919 large aircraft to the mobile phone casing. What are aluminum 7075 material properties?

It is available in various heat treatment tempers: T6, T73, T76, T77. Through a large number of experimental data and theoretical analysis, on the basis of 7075-T6, the aging heat treatment process was used to successfully develop 7075-T73, which is resistant to stress corrosion. Although this material sacrifices part of its static strength, its corrosion resistance has been significantly improved.

Later, 7075-T76 was further developed, which not only obtained stronger corrosion resistance, but also sacrificed a lower static strength than 7075-T73, which improved the comprehensive properties of aluminum alloy materials and became the best corrosion-resistant aluminum alloy.

7075 alloy can be resistance welded, and the long-term working temperature of the workpiece is less than or equal to 125℃. For incomplete annealing of materials or workpieces, the specification is 290°C~320°C, and after holding for 2h~4h, it is air cooled. Complete annealing specification is (390~430)℃/(0.5~1.5)h and it should be cooled down to ≤200℃ with a cooling rate not greater than 30℃/h.

The solution treatment temperature of 7075 alloy sheet is 460℃~490℃, and the treatment temperature of aluminum sheet should be close to the lower limit, and the number of repeated treatments should not be more than 2 times, so as to prevent alloy elements from diffusing through the aluminum clad layer and reducing the corrosion resistance of the material.

AA7075 composition

Alloy	Si	Fe	Cu	Mn	Mg	Cr	Zn	Zr	Ti	Standard
7075	0.40	0.50	1.2-2.0	0.30	2.1-2.9	0.18-0.28	5.1-6.1	–	0.20	GB/AMS/EN

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Why Is Aluminium Used For Aircraft Bodies

According to reports, for every 1 kg reduced, the launch cost of the spacecraft will save about 20,000 dollars. Therefore, structural weight reduction can be described as a “gramme care” in the aerospace field.

If the weight of the fighter is reduced by 15%, the taxiing distance of the aircraft can be shortened by 15%, the range can be increased by 20%, and the effective load can be increased by 30%. Therefore, countries all over the world attach great importance to the research and development of lightweight structural materials for aerospace.

Aircraft aluminum alloy is widely used in the aerospace field due to its low density, moderate strength, easy processing and forming, strong corrosion resistance, rich resources, and strong recyclability. The skins, beams, ribs, stringers, bulkheads and landing gears on the aircraft can all be made of aluminum alloy.

Depending on the purpose of the aircraft, the amount of aluminum used varies. The aluminum alloy percentage in the manufacturing materials of civil aircraft that focus on economic benefits is very high. For example, the aluminum alloy used in the Boeing 767 passenger aircraft accounts for about 81% of the weight of the body structure.

At present, aluminum alloy materials used in aviation and civil aircraft mainly include: aluminum alloy castings, aluminum alloy forgings, large-section aluminum alloy extruded profiles, aluminum alloy thick plates, and aluminum-lithium alloys.

Aviation aluminum alloys are mainly deformable aluminum alloys that can be heat treated, such as 2000 and 7000 series aluminum alloys. Aluminum alloy 2024 is used for aircraft structural parts. 2048 aviation aluminum alloy is mainly used to manufacture aerospace vehicle structural parts and weapon structural parts.

2218 is mainly used in aircraft engines and diesel engine pistons, aircraft engine cylinder heads, jet engine impellers and compressor rings. 2219 is used for welding oxidizer tanks of space rockets, supersonic aircraft skins and structural parts.

7049 is used for aircraft and missile parts, such as landing gear hydraulic cylinders and extrusions. 7050 aviation aluminum alloy is used for medium and thick plates, extrusions, free forgings and die forgings of aircraft structural parts. 7178 aviation aluminum alloy is used to manufacture parts and components that require high compressive yield strength for aerospace vehicles.

7475 aluminum sheet is used for fuselage panels, wing skeletons, stringers, etc. 7A04 is used for aircraft skins, screws, and force-bearing components such as girder stringers, bulkheads, wing ribs, and landing gear. 7075 aluminum plate is used for the upper outer panel of the wing, stringer, wing rib, empennage,etc.

Original Source:https://www.aircraftaluminium.com/a/why-is-aluminium-used-for-aircraft-bodies.html