Electrochemical comparison between corrosion resistance of some thermally sprayed coatings. (29th September 2008)

• Record Type: Journal Article
• Authors: Bolelli, G.; Cannillo, V.; Giovanardi, R.; Lusvarghi, L.
• Is Part Of: International journal of surface science and engineering. Volume 2:Number 3/4(2008)
• Page Start: 222
• Page End: 239
• Publication Date: 2008-09-29
• Subjects: impedance spectroscopy -- electroplating -- plasma spraying -- HVOF -- high velocity oxygen fuel -- electrochemical polarisation tests -- corrosion resistance -- cermet coatings -- ceramics; Surfaces (Physics) -- Periodicals; Surface chemistry -- Periodicals; Surfaces (Technology) -- Periodicals; Tribology -- Periodicals; 530.417
• Languages: English
• ISSNs: 1749-785X

Abstract

Electrochemical polarisation and impedance spectroscopy tests in 0.1 M HCl and 0.1 M H2SO4 solutions were performed on HVOF-sprayed cermet coatings (WC-17% Co, WC-10% Co–4% Cr) and Atmospheric Plasma-Sprayed (APS) ceramics (Al2O3, Al2O2?13 wt%TiO2, Cr2O3) with APS bond coat (Ni-Co-Cr-Al-Y). Reference tests were also performed on hard chrome electroplating. Plasma-sprayed coatings offer limited substrate protection owing to interconnected porosity, although the bond coat promotes some forms of passivation in H2SO4 HVOF-sprayed cermets possess good corrosion resistance in both environments. Chrome electroplating shows comparatively better corrosion resistance in H2SO4, but worse in HCl.