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Effect of Al3+ on the surface microstructure and film formation mechanism of Zr-based conversion coatings with improved corrosion resistance performance on cold rolled steel.
- Source :
-
Electrochimica Acta . May2024, Vol. 487, pN.PAG-N.PAG. 1p. - Publication Year :
- 2024
-
Abstract
- Most Zr conversion coatings are prepared on Al alloys, with Al3+ from the substrate contributing significantly to the film growth process. Thus, the effect of Al3+ on the electrochemical characteristics, surface microstructure and film-formation mechanism of Zr-based conversion coatings on old- rolled steel (CRS) substrates was investigated by growing the coatings with and without Al3+ as an additive. Electrochemical tests indicated that the anticorrosion performance of the Zr-Al coatings prepared in the presence of Al3+ was greatly superior to that of Zr conversion coatings obtained in the absence of Al3+. Field-emission scanning electron microscopy and X-ray photoelectron spectroscopy analysis indicated that adding of Al3+ in the conversion bath changed the surface microstructure of the Zr coating, greatly promoted the deposition of Zr and F on the CRS substrate and increased the film thickness and density. Both coatings were embedded into the etched CRS substrates. The presence of Al3+ additive induced the formation of different coating components. The Zr coating mainly consisted of ZrO 2 and some FeF x , whereas the Zr-Al coatings comprised of ZrO 2 , ZrO x F y , Al 2 O 3 , AlF x and some FeF x. The present study results confirm the key role of Al3+ as an additive in the film formation and growth process of Zr coatings and its effect on enhancing the anticorrosion performance of CRS substrates in NaCl solutions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00134686
- Volume :
- 487
- Database :
- Academic Search Index
- Journal :
- Electrochimica Acta
- Publication Type :
- Academic Journal
- Accession number :
- 176541093
- Full Text :
- https://doi.org/10.1016/j.electacta.2024.144196