Effect of Thickness on the Morphology and Corrosion Behavior of Cerium-Based Conversion Coatings on AZ31B Magnesium Alloy

Abstract

Cerium-Based conversion coatings (CeCCs) were deposited onto AZ31B magnesium alloy substrates using a spontaneous reaction of CeCl3, H2O2 and gelatin in a water-Based solution. the coating thickness was adjusted by controlling the immersion time in the deposition solution. Prior to deposition, the AZ31B substrates were treated using an acid pickling in nitric acid and then an alkaline cleaning in sodium metasilicate pentahydrate. after deposition, the coated samples were immersed in a phosphate bath that converted cerium oxide/hydroxide into cerium phosphate. Electrochemical impedance spectroscopy, potentiodynamic polarization and neutral salt spray testing studies indicated that ∼100 nm thick CeCC had better corrosion performance than ∼400 nm coatings. Characterization of the CeCCs by transmission electron microscopy (TEM) revealed a three layer structure with different compositions.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Cerium-based conversion coatings; Coating thickness; Corrosion of magnesium alloys; Transmission electron microscopy

International Standard Book Number (ISBN)

978-111829121-4

International Standard Serial Number (ISSN)

1545-4150

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Springer, All rights reserved.

Publication Date

01 Jan 2012

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