Surface enhancement of trivalent chromium conversion coatings and methods thereof

Abstract

The present disclosure relates to substrates and methods of producing substrates thereof. The substrates have a metal substrate and treated with a deoxidizer prior to having a sol-gel coating disposed on the metal substrate. The sol-gel coating includes about 3 wt % to about 15 wt % by volume of an organic corrosion inhibitor to the sol-gel. Methods of applying the sol-gel coating are also disclosed.

What is claimed is: 
     
         1 . A method of preparing a coated substrate, comprising:
 cleaning a substrate by exposing a surface of the substrate to a solvent;   treating the surface of the substrate with a deoxidizing agent; and   applying a sol-gel coating to the surface of the substrate; and
 wherein the sol-gel coating comprises an inhibitor. 
   
     
     
         2 . The method of preparing a coated substrate of  claim 1 , wherein the solvent comprises isopropyl alcohol. 
     
     
         3 . The method of preparing a coated substrate of  claim 1 , wherein the deoxidizing agent comprises hydrogen fluoride and chromic acid. 
     
     
         4 . The method of preparing a coated substrate of  claim 1 , wherein the inhibitor comprises 2,5-dimercapto 1,3,4-thiadiazole (DMCT). 
     
     
         5 . The method of preparing a coated substrate of  claim 1 , wherein cleaning the substrate further comprises flooding the surface of the substrate with an aqueous alkaline cleaning composition. 
     
     
         6 . The method of preparing a coated substrate of  claim 1 , wherein the sol-gel coating comprises no chromium. 
     
     
         7 . A method of preparing a coated substrate, comprising:
 cleaning a substrate by exposing a surface of the substrate to a solvent;   treating the surface of the substrate with a deoxidizing agent; and   applying a sol-gel coating to the surface of the substrate; and
 wherein the sol-gel coating comprises an inhibitor comprising a mercapto-functional thiadiazole. 
   
     
     
         8 . The method of preparing a coated substrate of  claim 7 , wherein the sol-gel coating further comprises the mercapto-functional thiadiazole in an amount of about 1 wt % to about 15 wt % by volume of the sol-gel coating. 
     
     
         9 . The method of preparing a coated substrate of  claim 7 , wherein the sol-gel coating further comprises the mercapto-functional thiadiazole in an amount of about 3 wt % to about 10 wt % by volume of the sol-gel coating. 
     
     
         10 . The method of preparing a coated substrate of  claim 7 , further comprising applying a primer coating to the sol-gel coating to form the primer coating, wherein the primer coating comprises a metal. 
     
     
         11 . The method of preparing a coated substrate of  claim 7 , wherein applying the sol-gel coating comprises mixing the inhibitor with an organosilane and metal alkoxide, wherein a volume ratio of organosilane to metal alkoxide is about 5% to about 20%, wherein the metal alkoxide has been pretreated with an acid. 
     
     
         12 . The method of preparing a coated substrate of  claim 7 , wherein the inhibitor comprises 2,5-dimercapto 1,3,4-thiadiazole (DMCT). 
     
     
         13 . The method of preparing a coated substrate of  claim 7 , wherein the deoxidizing agent comprises hydrogen fluoride and chromic acid. 
     
     
         14 . The method of preparing a coated substrate of  claim 7 , wherein cleaning the substrate further comprises flooding the surface of the substrate with an aqueous alkaline cleaning composition. 
     
     
         15 . An article, comprising:
 a substrate;   a corrosion inhibitor coating composition disposed on a surface of the substrate, comprising:
 a sol-gel formulation comprising an organosilanes, a metal alkoxide; and 
 an inhibitor comprising a mercapto-functional thiadiazole. 
   
     
     
         16 . The article of  claim 15 , wherein the sol-gel formulation comprises the mercapto-functional thiadiazole in an amount of about 1 wt % to about 15 wt % by volume of the sol-gel formulation. 
     
     
         17 . The article of  claim 15 , wherein the inhibitor comprises 2,5-dimercapto 1,3,4-thiadiazole (DMCT). 
     
     
         18 . The article of  claim 15 , wherein the substrate comprises a metal, polymer, polymer composite, or combination thereof. 
     
     
         19 . The article of  claim 15 , wherein the article is a component or part of an aerospace vehicle or a marine vehicle. 
     
     
         20 . The article of  claim 19 , wherein the component or part of an aerospace vehicle or marine vehicle is an external surface thereof.