(481b) Spectroscopical Characterization of Thin Film Deposition Processes: Protective and Conversion Coatings

With the raise of environmental awareness and the renewed importance of environmentally friendly processes, surface pre-treatment processes based on chromates have been targeted by the United States Environmental Protection Agency. Indeed, this process has been subject to regulations under the Clean Water Act as well as other environmental initiates, and there is today a marked movement to phase the process out in the near future. Therefore, there is a clean need for new advances in coating technology that could provide practical options for replacing present industrial practices. Depending on the final application, such coatings might be required to be resistant to corrosion and/or act as chemically resistant coatings. Multi-oxide conversion coating (nanometer scale) films were successfully grown onto aluminum alloys from precursors based on aryl phosphate esters. These films were primarily characterized by X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. Thermal analysis methods were used to formulate a model describing the chemical vapor deposition (CVD) process leading to conversion coatings on solid substrates. The results presented illustrate the potential of this technology to replace chromate-based processes. Results showing the effectiveness of these films as a protective barrier for corrosive environments and as enhancement of adhesion properties of metallic substrates are presented.