Zarras P.,NAWCWD Code 4L4200D |
Guenthner A.,NAWCWD Code 4L4200D |
Irvin D.J.,NAWCWD Code 4L4200D |
Stenger-Smith J.D.,NAWCWD Code 4L4200D |
And 7 more authors.
ACS Symposium Series | Year: 2010
The Naval Air Warfare Center Weapons Division (NAWCWD) has investigated electroactive polymers (EAPs) as alternative cadmium pretreatment coatings. EAP coatings (polypyrrole derivatives) were synthesized with adhesion promoting groups and embedded with inorganic microparticles for both corrosion inhibition and lubricity. These polymers were coated onto high strength 4340 steel alloys. Several of these EAP coated high strength 4340 steel alloys failed at 24 hours exposure to neutral salt fog spray. However, a hexyl substituted polypyrrole coating showed improved corrosion inhibition as compared to poly(3-pyrrol-1-yl) propanoic acid. Lubricity studies were performed on several pyrrole compounds. These EAP coatings were tested against Cd plated high strength 4340 steel alloys as a control. Galling testing was performed in accordance with test method ASTM G98. Several of the polymer coatings provided little, if any, protection from steel on steel galling. Some of the coatings behaved like a grease and did not provide an accurate galling resistance measurement. The addition of graphite particles resulted in a slight improvement in the galling performance of the poly(3-pyrrol-1-yl) propanoic acid coating, while adding SiO2 particles led to a more pronounced improvement. © 2010 American Chemical Society.