Properties of Aluminium Alloys

Among the various properties of aluminium alloys following are notable :

a.    low density (2.7 gm/cc)
b.    high electrical and thermal conductivity, only next to Cu
c.    good resistance to atmospheric, water and seawater corrosion
d.    good machinability, formability and castability
e.    maintains good light reflectivity
f.    non-toxic, non-magnetic and non-sparking.

Aluminium is a soft but weak material whose strength is increased by strain hardening and several heat treatments. Aluminium is used as a matrix in several fibre reinforced composites. Al₂O₃ an oxide of Al is very hand and strong and can be dispersed in the matrix of Al by powder metallurgy to produce SAP (sintered aluminium product). Other reinforcing elements used in softer aluminium matrix are boron whiskers, stainless steel fibres and whiskers of Al₃Ni.

Alminium alloys are divisible in three groups :

a.    cast Al alloys
b.    wrought Al alloys
c.    aluminium composite reinforced with fibres or particles.