Corrosion Behavior of Plasma-Sprayed Cr۲O۳ and Cr۲O۳-۲۰YSZ Coatings in۱۳.۵wt%NaCl Solution with and Without Sealing

In the present work, Cr۲O۳ (C) and Cr۲O۳-YSZ (CZ) coating were produced using ball milling of the starting powders, mixing the milled powder, and subsequently atmospheric plasma spraying of the agglomerated powders on ۳۰۴L steel substrate. The corrosion behavior of the coatings with and without sealing was evaluated by electrochemical potentiodynamic polarization and electrochemical impedance spectroscopy as well as immersion tests in a ۳.۵% NaCl solution. The results of microscopic image analysis showed that addition of YSZ to C coating caused an increase in coating porosity from ۸.۷% to ۱۰.۲% and a decrease in splats degree of flattening. Data obtained from electrochemical tests indicated the better corrosion resistance for individual Cr۲O۳ coating that was related to its denser microstructure. Sealing treatment by limiting electrolyte access to the substrate surface considerably increased the corrosion resistance (ohm.cm۲) of the C and CZ coatings from ۱۹۱ and ۳۷۹ to ۲۳۱۸۹ and ۷۷۹۱۶, respectively

Keywords:

Nano , Ball milling , Cr۲O۳ , YSZ , Plasma spray , Corrosion behavior , EIS , Sealing , نانوکامپوزیت , آسیاکاری , Cr۲O۳ , YSZ , پاشش پلاسمایی , خوردگی , EIS , نشت بندی.