Aluminium alloys are some of the basic building materials of existing spacecraft and appear in many subsystems. Only a few specific points of special
interest for the spacecraft designer are considered here, since the general aspects of aluminium alloy assemblies are already well known in the similar field of aeronautical design.
Light alloys based on aluminium are used in:
-primary and secondary structures;
-Plumbing;
-plating in many applications (e.g. electronics, thermal control and corrosion protection);
-aluminized layers on other materials (see sub clauses A.11 (adhesive tapes) and A.17 (plastic
film));
-fillers in other materials to provide electrical or thermal conductivity.
In addition to standard alloys, more recent alloy developments include the following:
-Additions of lithium to increase mechanical performance and decrease density. Li-additions are often lower than other "conventional" alloying elements, so Al-Li alloys can appear within different alloy groups (2000-, 7000- and 8000-series wrought products).
-Reinforced alloys (metal matrix composites - MMC)
consisting of aluminium alloys reinforced with whiskers, metal wires, boron fibres or carbon fibres.
-Thin Al-alloy sheets with layers of fibre-reinforced polymer composite in between (Fibre Metal Laminates - FML).
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