Screening Study of Spray Solution Parameters for Depositing Cerium-Based Conversion Coatings on Al Alloy 2024-T3

Abstract

Cerium-based conversion coatings were deposited on aluminum alloy 2024-T3 by a spray process using a solution containing cerium chloride, hydrogen peroxide, and gelatin. As deposited coatings were composed of hydrated cerium oxide and were post-treated in a phosphate solution to improve corrosion performance. Coating solution parameters, including the pH (1–2.5), cerium chloride concentration (0.025–0.125 M), and hydrogen peroxide content (0–1.2 M), were varied to investigate the effect(s) of solution parameters on the corrosion performance of the post-treated coatings. Results indicated that thickness of coatings deposited from solutions with different pH values were similar, while coating thickness increased with increasing concentration of cerium chloride and hydrogen peroxide in the solutions. Electrochemical impedance spectroscopy and observations of the surface appearances of the coatings indicated that coatings deposited from solutions with a pH 2, a cerium concentration of 0.1 M, and a hydrogen peroxide concentration of 0.8 M exhibited the best corrosion resistance.

Department(s)

Materials Science and Engineering

Research Center/Lab(s)

Peaslee Steel Manufacturing Research Center

Keywords and Phrases

Industrial Chemistry/Chemical Engineering; Physical Chemistry; Electrochemistry; Al2024-T3; Cerium Conversion Coating; Solution Parameters; Corrosion; EIS

International Standard Serial Number (ISSN)

0021-891X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2009 Springer Verlag, All rights reserved.

Publication Date

01 Oct 2009

Link to Full Text

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