| The mechanism of metal oxidation is critical for modern industry, providing vital information on the corrosion protection properties, and, thus, the lifetime and stability of metallic structures. This is especially true for Al—the metal often coined the metal of the modern age, finding a wide range technological applications. The mechanism of the initial stages of the protective oxide film growth on aluminum surface is the subject of this thesis. The Al surface is automatically self-passivated under atmospheric conditions by means of the formation of its protective oxide film. I have investigated the oxidation of an Al single crystal by means of both thermal (oxygen, ozone) and hyperthermal agents (oxygen and water simultaneously with electron irradiation) in order to elucidate the details of the oxide growth process. Changes in the oxidation mechanism and kinetics induced by use of the non-thermal agents are a particular topic of my studies. I found that electrostatic effects are prevalent in the mechanism of Al metal oxidation, and both electron- and field-assisted processes cause dramatic increases in the oxidation rate. These effects are discussed in relation to the accepted Cabrera-Mott theory of low temperature metal oxidation. |
