Aluminium Alloys

Aluminum alloys – Aluminum (Al) + alloying elements like copper, magnesium, manganese, silicon, tin and zinc.

There are mainly two type of Aluminum alloys, casting alloys and wrought alloys. They are further subdivided into heat-treatable or non-heat-treatable alloys.

About 85% of aluminum is used for wrought products like rolled plate, foils and extrusions.

Cast aluminum alloys have low tensile strength in comparison to wrought alloys but they are preferred because of their low melting point. 

The most important cast aluminum alloy system is Al–Si, where the high levels of silicon (4.0–13%) contribute to give good casting characteristics.

Aluminum alloys are widely used in engineering structures and components where light weight or corrosion resistance is required. Aluminum alloys are used extensively in aircraft due to their high strength-to-weight ratio.

Wrought and cast aluminum alloys use different identification systems. Wrought aluminum is identified with a four digit number which identifies the alloying elements.

Cast aluminum alloys use a four to five digit number with a decimal point. The digit in the hundreds place indicates the alloying elements, while the digit after the decimal point indicates the form (cast shape or ingot).

Wrought Alloys

1000 series – pure aluminum minimum 99% aluminum content.

2000 series are alloyed with copper,

3000 series are alloyed with manganese,

4000 series are alloyed with silicon.

5000 series are alloyed with magnesium,

6000 series are alloyed with magnesium and silicon.

7000 series are alloyed with zinc,

8000 series are alloyed with other elements which are not covered by other series.

-F : As fabricated

-H : Strain hardened (cold worked) with or without thermal treatment

-O : Full soft (annealed)

-T : Heat treated to produce stable tempers

-W : Solution heat treated only

Aluminum Casting alloys as per attached table-