International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Zirconium dioxide-titanium dioxide coatings were obtained by sol-gel method on stainless steel plates. The samples were treated at three Zirconium dioxide-titanium dioxide coatings were obtained by sol-gel method on stainless steel plates. The samples were treated at three temperatures 300, 400 and 500oC. The morphology and chemical surface composition were examined by Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), while the phase composition was examined by X-ray diffraction analyses (XRD). The corrosion resistance was evaluated by weight loss measurements in NaCl medium. The coatings are possess relatively smooth surface with some microcracks. After corrosion test the coatings treated at 500oC, keep their surface structure without visible signs of corrosion and thecorrosion tests revealed zero mass loss. The good protective properties of these coatings could be attributed to (i) amorphous structure, leading to deterioration of the ion and electron conduction of the films and (ii) probably increased density after the thermal treatment

Three types of oxide sol gel coatings: TiO2, CeO2 and TiO2/CeO2 composite were deposited by sol gel method on stainless steel and carbon steel. The morphology was examined by means of Scanning electron microscopy (SEM). X-ray diffraction analyses (XRD) were applied to investigate the phase composition. The corrosion resistances of the coatings were studied by evaluation of the weight loss in NaCl medium for 1200 hours. The surface of the TiO2 samples were relatively dense with a few surface nanocrystals and after tests does not shown any signs of corrosion. Тhe composite TiO2/CeO2 samples possess deep cracks which evidently favor the attacks in corrosion medium. Ceria and titania coatings deposited on stainless steel have zero weight loss in corrosive medium. The TiO2 coatings could also effective protect carbon steel, while the TiO2/CeO2 and CeO2 coatings exhibited lower corrosion resistance.

Titanium dioxide coatings and zirconium dioxide were deposited on SiO2 underlayers by sol-gel method on stainless steel plates. The samples were treated at two different temperatures (500 and 700oC) in air. The morphology was examined by means of Scanning electron microscopy (SEM) and the phase composition by X-ray diffraction analyses. The corrosion resistance of the coatings were examined by evaluation of the weight loss in NaCl medium. The TiO2/SiO2 coatings possess relatively smooth surface with some crystallites on the surface, while ZrO2/SiO2 coatings are not so smooth. After treatment at higher temperature the ZrO2/SiO2 coatings become rougher. The weight loss measurement have proved that the TiO2/SiO2 coatings exhibit higher corrosion resistance in comparison to ZrO2/SiO2 coatings. The TiO2/SiO2 coatings, treated at 500oC after the corrosion test retain their characteristic grain structure without any cracks and other defects. Similar is the structure of these coatings, treated at 700oC. The better protective properties of TiO2/SiO2 could be attributed to their amorphous dense structure.