Why does Aeroplane choose Aluminum as its body?
Al is one of the lightest metals in the world: Al is almost 3 times lighter than iron but it's also very strong, and corrosion resistant because its surface is always covered with very strong layer of oxide film.
Aluminum is a silver-colored, low density. Unalloyed aluminum is ductile and strengthy.
So Aluminum is used extensively in the aerospace industry.
But Al has agening problem.
"Ageing":-
Hardness of Al is increases with its age naturally.That is called Ageing .And brittleness increases and ductileness decreases and will be braked.
Temp is proportional to Ageing.
So to avoid Ageing Al alloys keep in cooling system.