Aluminum ingot is a silvery white metal, and its content in the earth's crust ranks third after oxygen and silicon. The density of aluminum is very small, only 34.6 1% of iron and 30.33% of copper, so it is also called light metal.
Aluminum is a non-ferrous metal whose output and consumption are second only to steel in the world. The density of aluminum is only 2.7 103g/cm3, which is about 1/3 of steel, copper or brass. Because of its light weight, aluminum is often used to manufacture land, sea and air vehicles such as cars, trains, subways, ships, planes, rockets, spaceships, etc. to reduce its own weight and increase its load.