Aluminum for aircraft

aluminum sheet

Sheet aluminum is the base material in a modern aircraft. Usually sheets from aluminum alloys apply for the manufacture of an aircraft fuselage, wherein both the inner frame, and for the outer shell. Individual parts are connected to each other by rivets and other types of fasteners.

Aluminum sheet is widely used in many types of aircraft - from single-engine aircraft to airplanes. Sheet aluminum is produced by rolling metal into flat sheets of various thicknesses from thin sheet to thick sheet (s). In aircraft use of thick aluminum sheets 3,3 to 0,25 mm (from 8 to 30 gauges, as the Americans say).

Below are excerpts from the US leadership for civil aircraft maintenance technicians, where, along with other materials, the main place is occupied by aluminum alloys [1].

Aluminum and aluminum alloys

Sheets made of different aluminum alloys - is, what is most often encountered in the repair of aircraft. It is known, that aluminum in its pure form - it's easy, brilliant, corrosion-resistant, plastic. However, the level of pure aluminum is quite low strength.

If aluminum receives small additives (fractions and units of percent) of such elements, as copper, manganese and magnesium, the obtained aluminum alloys, which are used in aircraft.

Aluminum alloys such as lungs, as well as pure aluminum, but it is much stronger. They do not have the corrosion resistance like pure aluminum and usually require additional corrosion protection. One method of corrosion protection of aluminum alloys is plating the surface with a thin layer of aluminum. This layer was prepared by co-rolling aluminum and aluminum alloy. It protects the main aluminum alloy corrosion.

Aircraft construction and repair

Sheets of aluminum brand 1100 apply in cases, when the main factor is the strength not, and weight saving, and high resistance to corrosion. Sheets of this brand of aluminum used for the manufacture and repair of fuel tanks, fairings and oil tanks. Aluminum 1100 It is also used to repair the wing tips. Very good weldable.

Aluminium alloy 3003

This alloy is similar in application to aluminum 1100. It contains from 1,0 to 1,5 % manganese and therefore stronger and firmer, than aluminum 1100.

Aluminium alloy 2014

forgings, sheets and profiles of alloy 2014 used for manufacturing parts, which are subject to high loads, such as a wheel and the main bearing structures. This alloy is often used there, where high strength and hardness, and also to work at elevated temperatures.

Aluminium alloy 2017

This alloy is used for production of rivets. At the present time it is of limited use.

Aluminium alloy 2024

Alloy Sheets 2024 - plating with pure aluminum or without - used to manufacture aircraft frame members, rivets, fasteners and many other parts. Moreover, This alloy is used for thermally hardened parts, shell fuselage and extrusions.

Aluminium alloy 2025

This alloy is used for the manufacture of propeller blades.

Aluminium alloy 2219

Aluminum alloy sheet 2219 used for the manufacture and repair of fuel tanks, shell fuselage and an aircraft carrier structural elements. This alloy has a high fracture toughness and good welded. Alloy 2219 also has high resistance to stress corrosion.

Aluminium alloy 5052

Alloy 5052 used there, where good metal ductility is required, High resistance to corrosion, high fatigue strength, good weldability and medium static strength. This alloy is used for the fabrication of fuel, hydraulic and oil pipelines.

Aluminium alloy 5056

Alloy 5056 used for manufacturing the rivets and cable sheaths, as well as in those cases,, when the aluminum comes into contact with magnesium alloys. Alloy 5056 usually it is resistant to most forms of corrosion.

Casting aluminum alloys

Casting aluminum alloys are used for the manufacture of cylinder blocks, crankcases, fuel pumps and gear wheels.

Hardening aluminum alloys

Various aluminum alloys, including 3003, 5052 and 1100, hardened only by cold plastic deformation, instead of heat treatment.

other alloys, such as 2017 and 2024, hardening by thermal treatment, cold deformation, or a combination of both. Most foundry alloys are also hardened by heat treatment.

Aluminium alloy 6061

Alloy 6061 usually well welded by all industrial processes and welding methods. It also has a sufficiently high viscosity at cryogenic temperatures. Alloy 6061 fairly well pressed and generally used for production of hydraulic and pneumatic piping.

Aluminium alloy 7075

This alloy has a higher strength, than an alloy 2024, but lower fracture toughness. Usually it is applied, where high tensile strength, and the fatigue strength is not critical. In the state T6 alloy 7075 do not use in environments with high corrosivity. However, in the T7351 state (a variant of the overaged state), the alloy 7075 It has a higher resistance to stress corrosion and fracture toughness, than in the T6 condition. Condition T76 (a variant of the over-aged condition) is often used to increase the durability of the alloy. 7075 subsurface corrosion.

Aluminum alloys for long-haul aircraft

Aircraft structural materials, used in main components, such as the fuselage, wings, landing gear and tail, subjected to various loads/forces. for instance, aircraft fuselage is subjected to various forces, including compression, stretching, bend, torsion and pressure buildup, because it carries the entire payload. As another example, the upper surface of an aircraft wing is subjected to compression and the lower surface to tension during flight.

The figure 1 shown, what aluminum alloys 2024 and 7075 used in upper wing skin and stringers, because they have a good combination of the following properties: compressive yield strength, elastic modulus, fatigue strength, fracture toughness, fatigue crack growth and corrosion. The most commonly used aircraft structural materials are high-strength aluminum alloys., titanium alloys and polymer composites, reinforced with carbon fiber.

Fig. 1 – Materials selection for structural members of a typical passenger aircraft [2]


  2. Encyclopedia of Aluminum and Its Alloys / Eds. G. Totten, M. Tiryakioğlu, O. Kessler – 2019