Aluminum was discovered by Hans Oersted in Copenhagen, Denmark in 1825. Aluminum is a silvery white reactive metal which is usually covered by a tenacious oxide coating. This renders it inert to acids, but it is attacked by alkalies. It is the most common metallic element in the earth's crust (82000 ppm) and is extracted from the hydrated oxide, Bauxite, by electrolysis of the oxide dissolved in molten sodium hexafluoroaluminate (cryolite). The metal has good thermal properties and is malleable and ductile. Aluminum and its alloys are widely used for various applications including aircraft assemblies and engine parts.Powder - Small particles with an approximately defined size range. Those materials described as alloy precursors are not true alloys - they are made by sintering a blend of powders of the component metals to achieve alloying by diffusion. The resultant cake is ground and sieved to the required particle size range. Unless otherwise stated, the particle sizes shown are for guidance only. We do not guarantee either any particular size distribution between the quoted minimum and maximum sizes, or a specific particle shape.