Aluminum is a light metal, with a density only about one-third that of iron. Pure aluminum is soft, loses its tensile strength at around 300 °C, and has a melting point of 660.4 degrees. Treated aluminum alloys are tougher and more ductile. It has a metallic luster, the surface is silvery white and shiny when it is smooth, and dark gray when it is rough. Non-magnetic and difficult to ignite.
The ability to reflect visible light is strong (about 92%), and the reflection of medium and far infrared rays can reach 98%. The strength and toughness of pure aluminum is 7-11MPa, while the aluminum alloy can reach 200-600MPa. Aluminum is easy to machine, cut, and shape.
Aluminum has good electrical and thermal conductivity (both 59% of copper) and is much lighter than copper. Aluminum can superconduct at temperatures below 1.2K and magnetic fluxes greater than 100 Gauss.
Aluminum is easy to react with oxygen, and when exposed to air, dense aluminum oxide Al2O3 will be formed on its surface (this process is passivation), which effectively prevents it from continuing to oxidize, so it is usually slightly silver-gray.