What’s Aluminium like?
Aluminium is soft, lightweight, fire-proof and heat-resistant, easy to work into new shapes, and able to conduct electricity. It reflects light and heat very effectively and it doesn’t rust. It reacts easily with other chemical elements, especially oxygen, and readily forms an outer layer of aluminum oxide if you leave it in the air. We call these things aluminium’s physical and chemical properties.
Aluminium really comes into its own when you combine it with other metals to make aluminium alloys (an alloy is a metal mixed together with other elements to make a new material with improved properties—it might be stronger or it might melt at a higher temperature). A few of the metals commonly used to make aluminum alloys include boron, copper, lithium, magnesium, manganese, silicon, tin, and zinc. You mix aluminium with one or more of these depending on the job you’re trying to do.
Aluminium can be combined with other materials in a quite different way in composites (hybrid materials made from two or more materials that retain their separate identity without chemically combining, mixing, or dissolving). So, for example, aluminium can act as the “background material” (matrix) in what’s called a metal matrix composite (MMC), reinforced with particles of silicon carbide, to make a strong, stiff, lightweight material suitable for a wide variety of aerospace, electronic, and automobile uses—and (crucially) better than aluminium alone.