Thermal barrier coating repair compositions and methods of use thereof

Abstract

The present inventive subject matter is directed to repair compositions for thermal barrier coatings and methods of use thereof. The repair compositions include a ceramic composition, a colloidal solution, an aqueous binder, an aqueous dispersant, and an aqueous ammonia solution. The ceramic composition includes a first population of yttria-stabilized zirconia particles having a mean diameter from about 250 nm to about 1000 nm, a second population of yttria-stabilized zirconia particles having a mean diameter from about 2 μm to about 10 μm, and a third population of yttria-stabilized zirconia particles having a mean diameter from about 20 μm to about 250 μm. One method includes depositing the repair layer onto the damaged region, the repair layer including the repair composition, and heat treating the repair layer.

What is claimed is: 
     
         1 . A repair composition comprising:
 a ceramic composition in an amount of from about 40 to about 60 percent by volume of the repair composition;   a colloidal solution in an amount of from about 15 to about 25 percent by volume of the repair composition;   an aqueous binder in an amount of from about 5 to about 15 percent by volume of the repair composition;   an aqueous dispersant in an amount of from about 4 to about 8 percent by volume of the repair composition; and   an aqueous ammonia solution in an amount of from about 5 to about 10 percent by volume of the repair composition;   wherein the ceramic composition comprises:
 a first population of yttria-stabilized zirconia particles having a mean diameter from about 250 nm to about 1000 nm, in an amount of from about 15 to about 30 percent by volume of the ceramic composition; 
 a second population of yttria-stabilized zirconia particles having a mean diameter from about 2 μm to about 10 μm, in an amount of from about 10 to about 25 percent by volume of the ceramic composition; and 
 a third population of yttria-stabilized zirconia particles having a mean diameter from about 20 μm to about 250 μm, in an amount of from about 50 to about 70 percent by volume of the ceramic composition; 
   and wherein the colloidal solution comprises:
 an aqueous solvent in an amount of from about 90 to about 98 percent by volume of the colloidal solution; and 
 a fourth population of yttria-stabilized zirconia particles having a mean diameter from about 2 nm to about 200 nm, in an amount of from about 2 to about 10 percent by volume of the colloidal solution. 
   
     
     
         2 . The repair composition of  claim 1 , wherein the repair composition does not include silicone, silica, or silicate. 
     
     
         3 . The repair composition of  claim 1 , wherein the first population of yttria-stabilized zirconia particles, the second population of yttria-stabilized zirconia particles, the third population of yttria-stabilized zirconia particles, and the fourth population of yttria-stabilized zirconia particles have from about 4 to about 60 mole percent yttrium oxide content. 
     
     
         4 . The repair composition of  claim 1 , wherein the aqueous binder comprises water and a binder selected from the group consisting of poly(alkylene carbonate) copolymer, cellulose binder, poly(vinyl alcohol), and polyethylene glycol. 
     
     
         5 . The repair composition of  claim 1 , wherein the aqueous dispersant comprises ammonium polyacrylate and water. 
     
     
         6 . The repair composition of  claim 1 , wherein the aqueous ammonia solution comprises ammonia and water, wherein the ammonia is in an amount of from about 25 to about 50 percent by volume of the aqueous ammonia solution. 
     
     
         7 . The repair composition of  claim 1 , wherein the ceramic composition is in an amount of from about 45 to about 55 percent by volume of the repair composition; the colloidal solution is in an amount of from about 18 to about 22 percent by volume of the repair composition; the aqueous binder is in an amount of from about 10 to about 15 percent by volume of the repair composition; the aqueous dispersant is in an amount of from about 6 to about 8 percent by volume of the repair composition; and the aqueous ammonia solution is in an amount of from about 8 to about 10 percent by volume of the repair composition. 
     
     
         8 . The repair composition of  claim 1 , wherein the first population of yttria-stabilized zirconia particles is in an amount of from about 22 to about 28 percent by volume of the ceramic composition; the second population of yttria-stabilized zirconia particles is in an amount of from about 15 to about 20 percent by volume of the ceramic composition; and the third population of yttria-stabilized zirconia particles is in an amount of from about 55 to about 65 percent by volume of the ceramic composition. 
     
     
         9 . The repair composition of  claim 1 , wherein the first population of yttria-stabilized zirconia particles is in an amount of about 15 percent by volume of the repair composition; the second population of yttria-stabilized zirconia particles is in an amount of about 10 percent by volume of the repair composition; and the third population of yttria-stabilized zirconia particles is in an amount of about 30 percent by volume of the repair composition. 
     
     
         10 . The repair composition of  claim 9 , wherein the colloidal solution is in an amount of about 20 percent by volume of the repair composition; the aqueous binder is in an amount of about 10 percent by volume of the repair composition; the aqueous dispersant is in an amount of about 6 percent by volume of the repair composition; and the aqueous ammonia solution is in an amount of about 9 percent by volume of the repair composition. 
     
     
         11 . A repair composition comprising:
 a ceramic composition in an amount of from about 40 to about 60 percent by volume of the repair composition;   a colloidal solution in an amount of from about 15 to about 25 percent by volume of the repair composition;   an aqueous binder in an amount of from about 5 to about 15 percent by volume of the repair composition;   an aqueous dispersant in an amount of from about 4 to about 8 percent by volume of the repair composition; and   an aqueous ammonia solution in an amount of from about 5 to about 10 percent by volume of the repair composition;   wherein the ceramic composition comprises:
 a first population of yttria-stabilized zirconia particles having a mean diameter from about 250 nm to about 1000 nm; 
 a second population of yttria-stabilized zirconia particles having a mean diameter from about 2 μm to about 10 μm; and 
 a third population of yttria-stabilized zirconia particles having a mean diameter from about 20 μm to about 250 μm; 
   and wherein the colloidal solution comprises:
 an aqueous solvent in an amount of from about 90 to about 98 percent by volume of the colloidal solution; and 
 a fourth population of yttria-stabilized zirconia particles having a mean diameter from about 2 nm to about 200 nm. 
   
     
     
         12 . The repair composition of  claim 11 , wherein the first population of yttria-stabilized zirconia particles is in an amount of from about 15 to about 30 percent by volume of the ceramic composition. 
     
     
         13 . The repair composition of  claim 11 , wherein the second population of yttria-stabilized zirconia particles is in an amount of from about 10 to about 25 percent by volume of the ceramic composition. 
     
     
         14 . The repair composition of  claim 11 , wherein the third population of yttria-stabilized zirconia particles is in an amount of from about 50 to about 70 percent by volume of the ceramic composition. 
     
     
         15 . The repair composition of  claim 11 , wherein the fourth population of yttria-stabilized zirconia particles is in an amount of from about 2 to about 10 percent by volume of the colloidal solution. 
     
     
         16 . The repair composition of  claim 11 , wherein the first, second, third, and fourth populations of yttria-stabilized zirconia particles have from about 4 to about 20 mole percent yttrium oxide content 
     
     
         17 . The repair composition of  claim 11 , wherein the aqueous binder includes polypropylene carbonate and water. 
     
     
         18 . The repair composition of  claim 11 , wherein the aqueous dispersant includes ammonium polyacrylate and water. 
     
     
         19 . The repair composition of  claim 11 , wherein the aqueous ammonia solution includes ammonia and water, and the ammonia is in an amount of from about 25 to about 50 percent by volume of the aqueous ammonia solution. 
     
     
         20 . The repair composition of  claim 11 , wherein the mean diameter of the first population of yttria-stabilized zirconia particles is about 800 nm; the mean diameter of the second population of yttria-stabilized zirconia particles is about 4 μm; and the mean diameter of the third population of yttria-stabilized zirconia particles is about 25 μm. 
     
     
         21 . A repair composition comprising:
 a ceramic composition including a first population of yttria-stabilized zirconia particles, a second population of yttria-stabilized zirconia particles, and a third population of yttria-stabilized zirconia particles, wherein the first population has a mean diameter from about 250 nm to about 1000 nm, the second population has a mean diameter from about 2 μm to about 10 μm, and the third population has a mean diameter from about 20 μm to about 250 μm;   a colloidal solution including an aqueous solvent and a fourth population of yttria-stabilized zirconia particles, the fourth population having a mean diameter from about 2 nm to about 200 nm;   an aqueous binder;   an aqueous dispersant; and   an aqueous ammonia solution.   
     
     
         22 . The repair composition of  claim 21 , wherein the ceramic composition is in an amount of from about 40 to about 60 percent by volume of the repair composition. 
     
     
         23 . The repair composition of  claim 21 , wherein the colloidal solution in an amount of from about 15 to about 25 percent by volume of the repair composition, and the aqueous solvent is in an amount of from about 90 to about 98 percent by volume of the colloidal solution.