• MATERIALS

    Preparation and study of corrosion stability of composite coatings on the base of ZrO2 and TiO2

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 10, pg(s) 464-466

    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

  • MATERIALS

    EFFECT OF TREATMENT TEMPERATURE OF TiO2/SiO2 AND ZrO2/SiO2 COATINGS ON THEIR CORROSION STABILITY

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 5, pg(s) 222-224

    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.