Deepening oxidation of metal crystals by laser radiation
The theory of laser-induced oxidation of metals, namely Ti, was developed. The theory accounts for the action of the strong temperature gradient due to laser irradiation as well as the oxygen concentration gradient. This theory is based on the Wagner differential oxidation equation and determines the oxide film thickness depending on the number of laser pulses. Theoretical calculations were confirmed experimentally using a YAG:Nd laser beam at 1.06 μm, a pulse duration of 15 nm and an intensity of 2 MW/cm², which is 10% less than the ablation threshold. Raman and SEM studies show the formation of a TiO2 film of mixing structural phase (anatase and rutile). It was found that the volume fraction of these phases depends on the intensity of the laser irradiation.