Abstract
ITRO treatment is one of surface treatments based on flame treatment, which is used liquid petroleum gas containing silane compounds, and forms silica deposits on substrates. This treatment brings high adhesion strength for aircraft coatings with only one-time treatment. ITRO treatment could be promising technology in aviation industry because that is quick, easy, clean and less costly process compared with traditional surface treatment processes such as anodizing or chemical conversion process. However, few studies have focused on ITRO treatment and the bond mechanism of ITRO treatment has not been clarified so far. In this research, the bond mechanism of ITRO treatment was investigated by using Fourier transform infrared spectroscopy. The analysis of the non-coated samples revealed that silica, absorbed water and SiOH groups exist in the silica deposits on the aluminum substrates and the spectral absorbance of them increases as the number of treating increases. The SiOH groups could be the source of hydrogen bonds and the amount of them depends on the number of treating. Furthermore, the analysis of the coated samples revealed spectral peaks of ester and ether groups in the coating materials shift to low wavenumber. This means new hydrogen bonds were formed inside the coating materials around the silica deposits formed by ITRO treatment.
