Category: Aluminium Alloys For Aircraft Structures

An important consideration when using aluminium alloys (and other materials) in aircraft structures is softening that occurs at elevated temperature. Care must be taken when selecting materials for supersonic aircraft to ensure structural weakening does not occur owing to excessive heating. Material properties such as stiffness, strength, fatigue resistance and toughness are degraded at high temperature.…

Background The heat-treatment process of age-hardenable aluminium alloys called ageing is essential to achieve the high mechanical properties required for aerostructures. Without the ageing process, the heat-treatable alloys would not have the properties needed for highly loaded aircraft components. As mentioned, the ageing process is only effective in the 2000, 4000 (containing Mg), 6000, 7000…

Occasionally, existing aluminium alloys do not have all the properties required for an aerospace application, and so the aircraft industry develops a new alloy. The practice of developing new aluminium alloys was common in the era between the mid-1930s and 1970 to meet the needs of the rapid advances in the aerospace industry. For example,…

The 2000, 6000, 7000 and many 8000 alloys can be strengthened by age-hardening. It is only by age-hardening that aluminium alloys obtain the strength needed for use in highly loaded structures and, therefore, this process is critical in the construction of aircraft. We first examine the composition and uses of the age-hardenable alloys used in…

The use of non-age-hardenable wrought alloys in aircraft is limited because they lack the strength, fatigue resistance and ductility needed for structural components such as skin panels, stiffeners, ribs and spars. The proof strength of most tempered non-age-hardenable alloys is below 225 MPa, which is inadequate for highly stressed aircraft structures. However, these alloys are…

Casting and wrought alloys Aluminium alloys are classified as casting alloys, wrought non-heat-treatable alloys or wrought heat-treatable alloys. Casting alloys are used in their as-cast condition without any mechanical or heat treatment after being cast. The mechanical properties of casting alloys are generally inferior to wrought alloys, and are not used in aircraft structures. Casting…

Aluminium has been an important aerospace structural material in the development of weight-efficient airframes for aircraft since the 1930s. The development of aircraft capable of flying at high speeds and high altitudes would have been difficult without the use of high-strength aluminium alloys in major airframe components such as the fuselage and wings. Compared with…