Effects of water and hydrogen on early stage oxidation of high purity titanium

Study has been made of the effects of hydrogen to early stage oxidation on a titanium surface under different treatments. Characterization of oxide layers was performed by using AES and XPS. Some influence of hydrogen on the titanium oxidation during the surface treatments was established by obtaining depth profiles of hydrogen with ERDA. The depth profiles showed extremely high-density of hydrogen in the surfaces, especially depending on MCP and BP treatments, In the samples of titanium hydrides, the deformed valence band spectra of energy states between 3 and 13 eV consistent with hydride formation were observed by XPS. To estimate surface chemical affinity of gas species, TDS was applied to each titanium surface. The TD spectra of H-2 and H2O showed significant differences among three kinds of solvents; water, alcohol and carbon tetrachloride. It has been suggested that mechanical and chemical processes of the surface treatment play an important role at an early stage of titanium surface oxidation.