Improved corrosion protection of aluminum alloys by system approach interface engineering : Part 1-Alclad 2024-T3

• Published in: Corrosion (Houston, Tex.) Tex.), 2000-08, Vol.56 (8), p.819-831
• Main Authors: REDDY, C. M, YU, Q. S, MOFFITT, C. E, WIELICZKA, D. M, JOHNSON, R, DEFFEYES, J. E, YASUDA, H. K
• Format: Article
• Language: English
• Subjects: Alloy systems; Aluminium; Aluminum; Aluminum base alloys; Analytical methods; Applied sciences; Cathodic coating (process); Chromate; Chromating; Coatings; Corrosion; Corrosion effects; Corrosion prevention; Corrosion resistance; Corrosion resistant alloys; Corrosion tests; Direct current; Electrocoatings; Engineering; Exact sciences and technology; Metals. Metallurgy; Photoelectron spectroscopy; Photoelectrons; Plasma; Plasmas (physics); Polymer coatings; Polymers; Primers (coatings); Protection; Protection systems; Salt spray tests; Sulfur; Sulfur dioxide; Sulphur; Sulphur dioxide; Surface preparation; X ray photoelectron spectroscopy
• ISSN: 0010-9312; 1938-159X
• DOI: 10.5006/1.3280585

This study investigated the development of chromate-free corrosion protection systems for Alclad 2024-T3 (UNS A92024) aluminum alloy ([2A]) based on the concept of system approach interface engineering (SAIE) by chemical and plasma techniques. Anode magnetron enhanced direct current (DC) cathodic plasmas were used to treat [2A] surface and to create interface engineered systems of cathodic electrocoat (E-coat)/plasma polymer/plasma-treated [2A]. Plasma polymer coatings provided not only a corrosion-resistant layer on [2A] surface but also an excellent adhesion base for subsequent cathodic E-coat. When tested by sulfur dioxide (SO2) and Prohesion salt spray tests, these plasma-modified systems showed excellent corrosion protection characteristics. The corrosion test results of SO2 and Prohesion salt spray tests showed that most of these plasma polymer-coated systems outperformed or performed comparably to the two types of controls used in this study (i.e., chromate conversion-coated and E-coated or chromated primer [Deft 44-GN-36] painted [2A] panels). The sample surface preparation effect on the corrosion performance of these plasma interface engineered systems also was studied, and x-ray photoelectron spectroscopy (XPS) was used to monitor the surface composition changes on [2A] surfaces.