Discuss the advantages and disadvantages of aluminium as compared to copper as a conductor of electricity.
Advantages:
Aluminium as a conductor of electricity as compared copper:
The electrical conductivity of aluminium is subsequent to that of copper. Resistivity of it is 2.8X10-8 ohm- m that is about 1.6 times higher than copper. Density of it is 2.68 which implies that aluminium is much lighter than copper. Melting point of it is 6550C. As copper, it can be easily drawn in thin wires. Aluminium is soft metal but while alloyed with some other materials as magnesium, iron or silicon, this gets higher mechanical strength and can be used for overhead transmission lines. As copper, aluminium forms also an oxide layer over its surface while exposed to atmosphere and which layer prevents the material from any oxidation and serves as a resistance layer to corrosion.
Disadvantages:
Because aluminium is a soft material, there is always a possibility of loose contacts. Because of the insulating property of aluminium oxide formed at the surface, this is difficult to solder aluminium wires. Though, for applications as winding of electrical machines and transformers, this is difficult to substitute aluminium for copper. It is because aluminium wires have lower tensile strength than copper.