Abstract:
In this thesis, an attempt is made to develop a three layer coating structures to protect steel against corrosion. The first layer is a silica sol-gel thin film, the second layer is a gallium thin film, and the third layer is a mixture of Na2SiO3 and Na2SiF6. The coatings are applied onto carbon steel substrates, with several types of chemical pretreatments. The samples were examined by SEM/EDS for the coatings' interaction between each other and the pretreated steel. Three samples of multi-layer coatings with specifically selected pretreatments were coated with the three layers and subjected to 12 M Hydrochloric acid, and observed to fail the test.
