Oxid coatings on aluminum

INTEREST in oxid coatings on aluminum began with the discovery of the metal about 100 years ago, for the chemical attraction of aluminum for oxygen is one of the most important characteristics of the metal. At various times in the history of aluminum, attention, from the scientific standpoint or from the commercial point of view, has been focused on the oxid film. To the scientist, for example, the electrical characteristics of the oxid film have been of great theoretical interest and for many years have been the subject of experimental study and speculation. Important commercial uses of the film in various electrical devices have followed upon the scientific studies.