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Wednesday, March 19, 2008 - 2:45 PM
Convention Center, Second Level, 220 (Ernest N. Morial Convention Center)
The Use of Mg Alloys in Mg-rich Primers
As an alternative to toxic Chromate coating, Mg-rich primer was designed to protect Al alloys (in particular Al 2024 T3) and developed in analogy to Zn-rich primers for steel substrate. The Mg pigments present in the primer can provide cathodic protection to Al substrate and show the promise to keep Al alloy away from corrosion when damage occurs. In order to determine how much the pigment composition can be varied without sacrifying corrosion protection, different primers in which magnesium alloy powders were used as pigments were formulated with an epoxy-polyamide polymer binder at different pigment volume concentrations. Their behaviour was studied after cyclic exposure in Prohesion Chamber via electrochemical methods. Testing results from Electrochemical Impedance Spectroscopy (EIS) and Scanning Electron Microscopy (SEM) showed that the metal-rich primers with Mg alloys as pigments could provide certain cathodic protection, and the precipitate of Mg oxides/hydroxides from their oxidation might introduce some barrier protection. Furthermore, the investigation of the properties of the alloy pigments gave a good understanding of the effects of particle shape, particle size, particle size distribution and chemical composition.
See more of Research in Progress - Coatings and Inhibitors
See more of Research in Progress
See more of The CORROSION 2008 Conference and Expo (March 16-20, 2008)
See more of Research in Progress
See more of The CORROSION 2008 Conference and Expo (March 16-20, 2008)