Abstract
Corrosion properties of nanostructured coatings deposited by suspension high-velocity oxy-fuel (S-HVOF) via an aqueous suspension of milled WC-Co powder were compared with conventional HVOF-sprayed coatings. Microstructural evaluations of these coatings included x-ray diffraction and scanning electron microscopy equipped with an energy-dispersive x-ray spectroscopy. The corrosion performance of AISI440C stainless steel substrate and the coatings was evaluated in a 3.5 wt.% NaCl aqueous solution at ~ 25 °C. The electrochemical properties of the samples were assessed experimentally, employing potentiodynamic polarization and electrochemical impedance spectroscopy. The potentiodynamic polarization results indicated that coatings produced by S-HVOF technique show lower corrosion resistance compared with the coatings produced by HVOF-JK (HVOF Jet Kote) and HVOF-JP (HVOF JP5000) techniques. Results are discussed in terms of corrosion mechanism, Bode and Nyquist plots, as well as equivalent circuit models of the coating–substrate system.
Original language | English |
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Pages (from-to) | 1579–1593 |
Number of pages | 15 |
Journal | Journal of Thermal Spray Technology |
Volume | 27 |
Early online date | 30 Oct 2018 |
DOIs | |
Publication status | Published - Dec 2018 |
Keywords
- corrosion
- HVOF
- nanostructured coatings
- S-HVOF
- suspension spraying
- WC-Co feedstock
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Materials Chemistry