DEVELOPMENT OF AN IMPROVED RINSE SOLUTION FOR PHOSPHATE COATINGS THROUGH ADDITION OF ORGANIC ACIDS
ARMY WEAPONS COMMAND ROCK ISLAND IL RESEARCH DEVELOPMENT AND ENGINEERING DIRECTORATE
Pagination or Media Count:
Work was undertaken in order to improve the salt spray resistance capabilities of phosphate coatings through innovations in the post treatment of the phosphate coatings and specifically through improvements in the supplementary rinse solutions. Various compounds, both organic and inorganic, were tested in solution, both by themselves and in combination with each other and with the existing chromic acid rinse solution, as possible rinses for phosphate coatings. It was found that four different 1-4 and 1-5 dicarboxylic acids, when used in the proper concentration with the existing 0.6 gmliter 0. 08 oz.gal. chromic acid rinse increased the salt spray life of a phosphate coating by at least one hour over the salt spray life of a coating treated in the standard 0.6 gm1 chromic acid rinse. These four acids are citric acid, glutaric acid, maleic acid and succinic acid. It was also found that one aromatic dicarboxylic acid tested, phthalic acid, had the same effect on the salt spray life as the above mentioned aliphatic acids.
- Coatings, Colorants and Finishes