Oxidation of Aluminum in the Temperature Range 400°–600°C

The surface oxidation kinetics of metallographically polished high purity aluminum were studied in the temperature range 400°–600°C using a vacuum microbalance technique. The oxidation rate of aluminum decreased to a low value after a formative stage of film growth which was governed by a parabolic law. Values of the activation energies of reaction were determined from the temperature coefficient of the parabolic law constants and were compared with other values reported in the literature. By attaching equal significance to gaseous and anodic oxidation results, a value of 37.2 kcal/mole (1.6 ev) was determined for the potential energy barrier against ion diffusion at the metal/oxide interface.