A20X - High Strength, Elevated Temperature Aluminium Casting Alloy

The aerospace and automotive industries are striving to reduce their carbon footprints and relative impact on the environment. New component design is being driven by reducing component weight and increasing operating temperatures and pressures. Light-weight, high strength materials are at a premium in terms of both aerospace and automotive design. Historically, wrought aluminium such as the 2000 and 7000 series alloys exhibit respectively higher strength and superior elevated temperature properties than cast alloys. High strength/elevated temperature aluminium-copper based cast alloys do exist (A201/K-01), however difficulties associated with the ‘castability’ of these alloys has limited the widespread integration of these alloys particularly in the aerospace industry. ‘Castability’ issues include; severe hot-tearing, a high susceptibility to the formation of shrinkage porosity, segregation and compositional inhomogeneity, mechanical property inconsistency and poor weldability.

Aeromet International Plc have developed ‘A20X’, a modified version of A201 where the aforementioned issues have been eliminated through small but significant compositional modifications resulting in alterations to the solidification mechanisms of the alloy. The castability of A20X is equivalent to current aerospace and automotive casting alloys allowing large and complex components to be cast. The modified solidification mechanisms allow for a significantly reduced feeding requirement and a reduction in the use of mould chills, thus resulting in simplified mould designs and increased metal yields even when compared to aluminium-silicon based casting alloys. A20X is highly weldable and its properties are comparable with both the 7000 and 2000 series wrought materials allowing castings to compete, realistically, with fabrications, forgings and machined from solid production routes.