Electrolytic and spontaneous spray deposition of organic assisted cerium conversion coatings for the corrosion protection of aluminum alloys

Author

Alexander Albert Williams

Abstract

"The primary goal of this study is to make, characterize and evaluate cerium conversion coatings on aluminum alloys prepared with the assistance of gelatin and certain amino acids. These coatings are potential replacements for chromate conversion coatings which, are very effective. Unfortunately, chromium is targeted for elimination from the workplace because it is very toxic. The important factors in the development of the cerium conversion coating process are cleaning temperature, current density, potential, pH, cerium concentration, additive concentration, coating time, and post deposition treatments. Both electrolytic and spray applied processes have been developed using gelatin and/or amino acids to assist the deposition of the cerium conversion coating on aluminum alloy 7075 T-6 that gave greater than 80% pass rate for the ASTM B-117 salt fog corrosion test. The process included an alkaline cleaning step, application of an acidified containing cerium containing gelatins and/or amino acids solution by either an electrolytic or spray deposition, followed by sealing in a boiling aqueous sodium phosphate solution. These organic additive assisted cerium conversion coatings offer better corrosion protection, thicker coatings, more polarization, and better uniformity that those deposited from an aqueous electrolyte without organic additive"--Abstract, page iv.

Department(s)

Chemistry

Degree Name

Ph. D. in Chemistry

Publisher

University of Missouri--Rolla

Publication Date

Fall 2005

Journal article titles appearing in thesis/dissertation

• Electrodeposition of gelatin assisted cerium conversion coating
• Comparative study of the effects of gelatins on electrodeposition of cerium conversion coating
• Corrosion protection of electrodeposition cerium conversion coatings aluminum alloy 7075 T-6 utilizing amino acids as organic additives coatings
• Development of gelatin and amino acid assisted spontaneous spray cerium conversion coatings

Pagination

xiv, 175 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2005 Alexander Albert William , Jr., All rights reserved.

Document Type

Dissertation - Citation

File Type

text

Language

English

Subject Headings

Coating processes -- Technological innovationsAluminum alloys -- CorrosionCorrosion and anti-corrosivesGelatinAmino acidsHydrogen peroxide

Thesis Number

T 8838

Print OCLC #

74889846

Recommended Citation

Williams, Alexander Albert, "Electrolytic and spontaneous spray deposition of organic assisted cerium conversion coatings for the corrosion protection of aluminum alloys" (2005). Doctoral Dissertations. 1640.
https://scholarsmine.mst.edu/doctoral_dissertations/1640