Corrosion Inhibiting Primers for Aluminum Alloys.

摘要

The purpose of this investigation was to develop an epoxy primer which would be superior to the MIL-P-23377B epoxy primer for protecting aluminum against corrosion. Epoxy primers which contain high amounts of leachable chromate pigments (SrCr04,or SrCr04 + CaCr04) were found to afford better corrosion protection for aluminum than the specification epoxy primer. However,the former tend to blister more in water than the specification primer when topcoated with either the MIL-C-22750epoxy or the MIL-C-81773(AS) polyurethane topcoats. Epoxy primers made with a high pigment content of zinc chromate pigment gave the best corrosion protection for aluminum. However,these primers,when topcoated with either epoxy or polyurethane and dried for several days at about 75F and 75% RH,tend to fail intercoat adhesion in the wet tape test. (Author)