Sol-gel coating method and composition

摘要

A coating composition and a method for coating metallic substrates, such as aircraft components exposed to elevated temperatures and/or oxidative conditions. The coating composition includes an aqueous mixture having about 2 vol % to about 50 vol % organosilane, about 0.3 to about 25 vol % metal alkoxide, and about 0.1 to about 30 vol % organic complexing agent. The coating composition may be deposited on a metallic substrate and cured to form a sol-gel coating on the surface of the substrate that is adherent to the substrate, and oxidation and discoloration resistant.

主权项

1. An aqueous sol-gel coating composition for coating a metallic aircraft component comprising:
an organosilane, a metal alkoxide; and an organic complexing agent; wherein the metal alkoxide is a compound having the general formula Zr(R—O)4; wherein R is a lower linear or branched aliphatic, alicyclic or aryl moiety having 2 to 8 carbon atoms; wherein the complexing agent is selected from the group consisting of acetic acid, oxalic acid, citric acid, acetylacetonates, glycols, ethoxyethanol, ethanolamine, and combinations thereof; wherein a ratio of metal alkoxide to organic complexing agent is about 2:1 by volume percent; wherein the coating composition is devoid of pigment and the total volume percent of the components in the aqueous composition is less than about 50% and the composition forming an adherent bond to metallic substrates when cured and providing a cured coating structure resistance to oxidation and discoloration.