This chapter starts with a brief overview of the historical development of aerospace aluminum alloys. This is followed by a listing of a range of current alloys with a description of the alloy classification system and the wide range of tempers in which Al alloys are used. A description is given of the alloying and precipitation hardening behavior, which is the principal strengthening mechanism for Al alloys.
A survey of the mechanical properties, fatigue behavior and corrosion resistance of Al alloys is followed by a listing of some of the typical aerospace applications of Al alloys. The Indian scenario with respect to the production of primary aluminum and some aerospace alloys and the Type Certification process of Al alloys for aerospace applications are described. Finally, there is a critical review of some of the gaps in existing aerospace Al alloy technologies.
Aluminum alloys have been the main airframe materials since they started replacing wood in the late 1920s. Even though the role of aluminum in future aircraft will probably be somewhat diminished by the increasing use of composite materials, high-strength aluminum alloys are, and will remain important airframe materials.