Improved Corrosion Protection Of Aluminum Alloys By Low Temperature Plasma Interface Engineering

The System Approach Interface Engineering (SAIE) concept was employed to develop corrosion protection processes for aluminum (Al) alloys by application of a low temperature plasma interface engineering technique with a cathodic electrocoat (E-coat) as the primary layer coating. The SAIE concept emphasizes that the corrosion protection property of the coated system for Al alloys depends on the total system rather than any good corrosion protection component of the system. The cathodic E-coated SAIE plasma pretreatments on Alclad 2024-T3, 2024-T3 bare and 7075-T6 bare alloys showed excellent corrosion resistance property when tested by SO 2 and Prohesion salt spray tests. These systems out performed the conventional conversion coated controls, chromate conversion coated then Deft primer coated (CC Deft) and chromate conversion coated then cathodic E-coated (CC E-coat) in both the corrosion testes. The corrosion protection by SAIE systems depends on three major factors; (1) improved barrier characteristics of E-coat, (2) water insensitive adhesion of E-coat to plasma polymers deposited in a DC discharge and (3) creating a stable surface oxide layer by plasma treatment or chemical cleaning. Different chemical pretreatments were employed to create a stable barrier type aluminum oxide layer on the surfaces of the substrates prior to plasma polymer deposition. The surface analysis showed that these pretreatments depend on the type of alloy and surface chemistry. As received surfaces with acetone wipe and plasma cleaning of the organic contaminants was found to be best for Alclad 2024-T3 alloy. Chemical alkaline cleaning for 2024-T3 bare and alkaline cleaning followed by deoxidization for 7075-T6 bare alloy were necessary. The adhesion of the cathodic E-coat was improved by surface energy matching techniques by deposition of various plasma polymer films of trimethylsilane (TMS) and mixtures of TMS with O 2, H 2, and N 2 . The adhesion performance evaluated by the N-methylpyrrolidinone (NMP) test method showed that the low temperature plasma interface engineering technique could be used to create adhesion performance range for the organic paint on the metal surfaces from easily removable to coatings for life. The barrier properties of the cathodic E-coat were improved by the plasma polymer deposition on which E-coat was applied.

The primary objective of this research project was to provide an alternative corrosion protection through means of processes more environmentally benign than conventional methodologies. Hexavalent chromium (Cr+6) has historically been acknowledged to exhibit the technological forefront in collision protection of aluminum alloys. The Systems Approach Interface Engineering (SAIE) concept, adopted in this project, emphasizes the fact that the corrosion protection of a metal depends on the overall corrosion protective behavior of an entire system, including the bulk characteristics of the coatings(s) and interfacial factors. The primary methodologies used were plasma processing. The technology showed superior corrosion resistant results to traditional aircraft coating systems. This technology is applicable to aircraft piece parts.

The growing use of light alloys in industries such as aerospace, sports equipment and biomedical devices is driving research into surface engineering technologies to enhance their properties for the desired end use. Surface engineering of light alloys: Aluminium, magnesium and titanium alloys provides a comprehensive review of the latest technologies for modifying the surfaces of light alloys to improve their corrosion, wear and tribological properties. Part one discusses surface degradation of light alloys with chapters on corrosion behaviour of magnesium alloys and protection techniques, wear properties of aluminium-based alloys and tribological behaviour of titanium alloys. Part two reviews surface engineering technologies for light alloys including anodising, plasma electrolytic oxidation, thermal spraying, cold spraying, physical vapour deposition, plasma assisted surface treatment, PIII/PSII treatments, laser surface modification, ceramic conversion and duplex treatments. Part three covers applications for surface engineered light alloys including sports equipment, biomedical devices and plasma electrolytic oxidation and anodised aluminium alloys for spacecraft applications. With its distinguished editor and international team of contributors, Surface engineering of light alloys: Aluminium, magnesium and titanium alloys is a standard reference for engineers, metallurgists and materials scientists looking for a comprehensive source of information on surface engineering of aluminium, magnesium and titanium alloys. Discusses surface degradation of light alloys considering corrosion behaviour and wear and tribological properties Examines surface engineering technologies and modification featuring plasma electrolytic oxidation treatments and both thermal and cold spraying Reviews applications for engineered light alloys in sports equipment, biomedical devices and spacecraft

Providing in-depth coverage of the technologies and various approaches, Luminous Chemical Vapor Deposition and Interface Engineering showcases the development and utilization of LCVD procedures in industrial scale applications. It offers a wide range of examples, case studies, and recommendations for clear understanding of this innovative science.

"These proceedings represent contributions to the Symposium on the Corrosion and Protection of Light Metals, held at the 204th Meeting of the Electrochemical Society, October 12th through 17th, 2003, in Orlando, Florida."--P. iii.

This volume chronicles the proceedings of the Fourth International Symposium on Silanes and Other Coupling Agents.This volume and its predecessors containing bountiful information should serve as a reference source for the latest R&D activity in the arena of coupling agents. Anyone interested or involved in promoting adhesion between dissimilar materials for any application should find this volume of great use and value.

Plasma electrolytic oxidation (PEO), also known as micro-arc oxidation (MAO), functionalizes surfaces, improving the mechanical, thermal, and corrosion performance of metallic substrates, along with other tailored properties (e.g., biocompatibility, catalysis, antibacterial response, self-lubrication, etc.). The extensive field of applications of this technique ranges from structural components, in particular, in the transport sector, to more advanced fields, such as bioengineering. The present Special Issue covers the latest advances in PEO‐coated light alloys for structural (Al, Mg) and biomedical applications (Ti, Mg), with 10 research papers and 1 review from leading research groups around the world.

This reference provides thorough and in-depth coverage of the latest production and processing technologies encountered in the aluminum alloy industry, discussing current analytical methods for aluminum alloy characterization as well as extractive metallurgy, smelting, master alloy formation, and recycling. The Handbook of Aluminum: Volume 2 examin