TECHNIQUES FOR PREPARING TITANIUM SURFACES FOR COATINGS AND SEALANTS.
Abstract
The titanium surface pretreatments are intended primarily for use at field maintenance level on operational aircraft and missiles. Three types of pretreatment techniques were developed. These vary from a chelated surface pretreatment that must be applied by immersion of the titanium in a chemical bath to a brush-on phosphorylation treatment that requires a 160C heat cure. An inorganic lacquer pretreatment prior to coating with interhalogen in CCl4 was shown to be our best pretreatment for titanium alloys giving maximum adhesion to polyurethane, silicone, acrylic and polysulfide type military coatings. Maximum coating adhesion was retained after extensive environmental exposure to salt fog, thermal cycling, 98 percent humidity and diester lubricating oil. These tests were performed on Ti-6Al-4V, Ti-8Al-1Mo-1V and Ti-13V-11Cr-3Al alloys. Titanium alloys having salicylaldehyde, 2,4-dihydroxybenzaldehyde and 8-hydroxyquinoline chelated surfaces gave good adhesion to all the coating systems investigated except the polysulfide sealant. A phospho-gel composite treatment was found that can be applied to titanium surfaces by a brush-on procedure. This treatment produces a hard surface coating on titanium alloys after a 160C heat cure. The phospho-gel undercoat gave good adhesion to acrylic, silicone and polyurethane coatings in preliminary tests. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1967
- Accession Number
- AD0825140
Entities
People
- John J. O'connell
- Stephen P. Terpko
Organizations
- Monsanto