Characterization by different analytical techniques of SiO2 and silane thin films deposited on rough hot-dip galvanized steel surfaces

The development of thin and environmental friendly coatings on steel surfaces constitutes a major objective of steelmaking industry. Within this objective it becomes necessary to develop analytical approach allowing characterization of so thin coatings on hot dip galvanized substrates in order to control the product quality. XPS, GDOES, SIMS, FTIR and Raman spectroscopies are compared in terms of capability to characterize SiO2-CVD and silane thin films on rough substrates. issue of this study, results show that the SiO2 coating of some tens of nm in thickness is continuous and appears to be homogeneous everywhere on the substrate surface. The layers deposited on the materials with sufficiently low roughness have almost similar thickness. In the case of significant surface roughness increase the SiO2 layer becomes thinner. lane coatings fill up substrate cavities during application and the coating thickness on rougher substrates is significantly higher than on smoother ones. The chemical composition of the silane layers is more uniform for rougher surfaces, whereas on smoother ones the Si concentration gradient is detected in depth.