Aluminium Properties 1.1 + 1.2

Pure aluminium is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking.
It is decorative. It is easily formed, machined, and cast. Alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties.
Strength depends on purity. 99.996 per cent pure aluminium has a tensile strength of about 49 megapascals (MPa), rising to 700 MPa following alloying and suitable heat treatment.
Although not found free in nature, Aluminium is an abundant element in the earth's crust.
A key property is low density. Aluminium is only one-third the weight of steel.
Aluminium and most of its alloys are highly resistant to most forms of corrosion. The metal's natural coating of aluminium oxide provides a highly effective barrier to the ravages of air, temperature, moisture and chemical attack.
Aluminium is a superb conductor of electricity. This property allied with other intrinsic qualities has ensured the replacement of copper by aluminium in many situations.
Aluminium is non-magnetic and non-combustible, properties invaluable in advanced industries such as electronics or in offshore structures.
Aluminium is non-toxic and impervious, qualities that have established its use in the food and packaging industries since the earliest times.
Other valuable properties include high reflectivity, heat barrier properties and heat conduction. The metal is malleable and easily worked by the common manufacturing and shaping processes.Physical Properties
Density / Specific Gravity (g.cm-3 at 20 °C)
2.70
Melting Point (°C)
660
Specific heat at 100 °C, cal.g-1K-1 (Jkg-1K-1)
0.2241 (938)
Latent heat of fusion, cal.g-1 (kJ.kg-1)
94.7 (397.0)
Electrical conductivity at 20°C(% of international annealed copper standard)
64.94
Thermal conductivity (cal.sec-1cm-1K-1)
0.5
Thermal emmisivity at 100°F (%)
3.0
Reflectivity for light, tungsten filament (%)
90.0
These properties can be very significantly altered with the addition of small amounts of alloying materials. Aluminium reacts with oxygen to form a microscopic (0.000000635cm) protective film of oxide, which prevents corrosion.
Aluminium in massive form is non-flammable. Finely divided particles will burn. Carbon monoxide or dioxide, aluminum oxide and water will be emitted. This is a useful property for making rocket fuel.