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Phosphate stabilization by non-chromate post-rinse treatment

Zinc phosphate conversion coating has been applied to improve the corrosion resistance and paint adhesion. However, zinc phosphate crystals dissolve in a highly alkaline environment, which reduces the corrosion resistance of base metal. To improve the phosphate stability in a highly alkaline environment, a post-rinse treatment has been applied to phosphate coating by rinsing with an aqueous solution which contains certain anions or cations. Chromatepost-rinse treatment is the most widely used method and has shown a great improvement in corrosion resistance. But, due to the environmental problems caused by chromate ions, non-chromate post-rinse treatment should be developed, which has equal or better corrosion resistance than does chromate post-rinse treatment. In this research, inorganic silicate with addition of Ca²⁺, Ba²⁺, Ni²⁺, Mg²⁺, has been extensively evaluated together with silane solution, γ -aminopropyltriethoxysilane ( γ -A.P.S., NH₂(CH₂)₃Si(OC₂H₅)₃), which was applied after the post-rinse treatment. The evaluation was carried out by the highly advanced surface analysis techniques such as SEM/EDX, AES, SIMS, and XRD and polarization measurements. / Master of Science

Identiferoai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/80009
Date January 1987
CreatorsYoon, Tae-Ho
ContributorsMaterials Engineering
PublisherVirginia Polytechnic Institute and State University
Source SetsVirginia Tech Theses and Dissertation
Languageen_US
Detected LanguageEnglish
TypeThesis, Text
Formatx, 100 leaves, application/pdf, application/pdf
RightsIn Copyright, http://rightsstatements.org/vocab/InC/1.0/
RelationOCLC# 17012875

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