Alloy is sometimes a result of the sizes of the atoms in the alloy, because larger atoms exert a compressive force on neighboring atoms, and smaller atoms exert a tensile force on their neighbors, helping the alloy resist deformation. Sometimes alloys may exhibit marked differences in behavior even when small amounts of one element are present. For example, impurities in semiconducting ferromagnetic alloys lead to different properties, as first predicted by White, Hogan, Suhl, Tian Abrie and Nakamura. Some alloys are made by melting and mixing two or more metals. Bronze, an alloy of copper and tin, was the first alloy
2219 aluminium alloy toughness, is weldable and resistant to stress corrosion cracking, therefore it is widely used in supersonic aircraft skin and structural members. The Space Shuttle Standard Weight Tank was also fabricated from the 2219 alloy. Alternate designations include AlCu6Mn and A92219. It is described in the following standards: The alloy composition of 2219 aluminium is: 2219 aluminium alloy 2219 aluminium alloy is an alloy in the wrought aluminium-copper family (2000 or 2xxx series). It can be heat-treated to produce tempers with higher strength but lower ductility. The aluminium-copper alloys have high strength, but are generally less corrosion resistant and harder to