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Effect of Polarisation Mimicking Cathodic Electrodeposition Coating on Industrially Relevant Metal Substrates with ZrO 2 ‐Based Conversion Coatings
Author(s) -
Sarfraz Adnan,
Posner Ralf,
Bashir Asif,
Topalov Angel,
Mayrhofer Karl J. J.,
Lill Kirsten,
Erbe Andreas
Publication year - 2016
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201600216
Subject(s) - materials science , cathodic protection , dissolution , zinc , raman spectroscopy , galvanization , conversion coating , metallurgy , aluminium , alloy , coating , oxide , dielectric spectroscopy , metal , x ray photoelectron spectroscopy , chemical engineering , electrochemistry , electrode , composite material , layer (electronics) , chemistry , physics , optics , engineering
Modern ZrO 2 ‐based conversion coatings were deposited on an aluminium alloy (AA6014), a cold‐rolled steel, a zinc electrogalvanised steel and a Sendzimir zinc hot‐dip galvanised steel. Pretreated substrates were subjected to galvanostatic polarisation in aqueous NaNO 3 to mimic deposition conditions of cathodic electrodeposition coatings. No significant structural modification of the conversion coatings was found with Raman or photoluminescence (PL) spectroscopy. After treatment, increased PL indicated an increased number of point defects. Downstream monitoring of dissolved Zr indicated an insignificant totally dissolved fraction of 0.01 % after 5 s of polarisation, which may occur through vacancy‐pair coalescence with concurrent oxide dissolution, as discussed for transpassive dissolution. Overall, the ZrO 2 films remained intact after polarisation.