Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 40 pages
File Size : 48,6 Mb
Release : 2018-07-13
Category : Electronic
ISBN : 1722853360
The Corrosion Protection of 6061-T6 Aluminum by a Polyurethane-Sealed Anodized Coat by National Aeronautics and Space Administration (NASA) Pdf
The corrosion protection of 6061-T6 anodized aluminum afforded by a newly patented polyurethane seal was studied using the ac impedance technique. Values of the average corrosion rates over a 27-day exposure period in 3.5 percent NaCl solutions at pH 5.2 and pH 9.5 compared very favorably for Lockheed-prepared polyurethane-sealed and dichromate-sealed coats of the same thickness. Average corrosion rates for both specimens over the first 7 days of exposure compared well with those for a hard anodized, dichromate-sealed coat, but rose well above those for the hard anodized coat over the entire 27-day period. This is attributed both to the greater thickness of the hard anodized coat, and possibly to its inherently better corrosion protective capability. Danford, M. D. Marshall Space Flight Center ...