In:
Materials and Corrosion, Wiley, Vol. 72, No. 5 ( 2021-05), p. 925-935
Abstract:
The cerium salt chemical conversion baths containing KMnO 4 are applied to prepare protective coatings on the WA42 alloy surface, and the effect of the concentration of KMnO 4 on the microstructure and corrosion properties of the coatings is investigated by scanning electron microscopy, X‐ray photoelectron spectroscopy, and electrochemical tests. The results indicate that with the addition of KMnO 4 to the conversion bath, the microstructure of the coating is more uniform and denser, and the coating with the KMnO 4 concentration of 4 g/L (4M coating) has the most uniform microstructure with the least microcracks. The 4M coating exhibits a two‐layered structure, and it is mainly composed of MgO, Mg(OH) 2 , CeO 2 , Ce 2 O 3 , Ce(OH) 3 , MnO, and MnO 2 . In addition, as the KMnO 4 concentration increases from 0 to 6 g/L, the I corr of the coatings in 3.5% NaCl solution decreases first and then increases, and the 4M coating shows the best corrosion resistance, which should attribute to the uniform and dense microstructure.
Type of Medium:
Online Resource
ISSN:
0947-5117
,
1521-4176
DOI:
10.1002/maco.202012166
Language:
English
Publisher:
Wiley
Publication Date:
2021
detail.hit.zdb_id:
1481051-7
detail.hit.zdb_id:
1224916-6
detail.hit.zdb_id:
202688-0
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