Aluminium Alloy Properties

Pure aluminium is relatively soft. To overcome this, the metal can be alloyed with other metals (alloying elements). Most of the aluminium reaching the marketplace has been alloyed with at least one other element.

Alloy code

Characteristics

1xxx Series

Contains no alloying elements. The proportion of aluminium is 99.3 – 99.9% and the rest is formed by tiny impurities. The combination of material properties, especially superior conductivity makes these alloys suitable for applications mainly in electrical and heat-power industry. Materials of this series are considered non-hardenable alloys and have tensile strengths of 40 – 60 MPa.

2xxx Series

The alloying element is copper. Alloys of this series are high strength alloys. The strength is achieved by the heat treatment process. The tensile strength is about 400 MPa on completion of hardening. Alloys of this series are considered not suitable for surface treatments and poor for welding.

3xxx Series

The alloying element is manganese. Alloys of this series are moderate in strength, they have good formability and they are suitable for anodizing and welding.

4xxx Series

The alloying element is silicon.

5xxx Series

The alloying element is magnesium. Alloys of this series are moderate in strength (200 – 350 MPa). The strength is achieved by the heat treatment processing or forming. Alloys of this series have excellent resistance to corrosion in aggressive atmosphere and seawater.

6xxx Series

The alloying elements are magnesium and silicon. Alloys of this series are moderate in strength (200 – 350 MPa). The strength is achieved by the heat treatment processing or forming. Alloys of 6xxx series can be easily anodized.

7xxx Series

The alloying element is zinc. Alloys of this series have the highest strength among all series. The tensile strengths ranging between 450 – 500 MPa may exceed 600 MPa in some cases. These alloys prone to stress corrosion, especially when welded.

8xxx Series

The alloying element is other than for the other series (including lithium).