Seal coat
A coating for an article includes a seal coat comprising self-healing particles disposed in a seal coat matrix and a bond coat disposed on the seal coat. The bond coat includes a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix. A coating for an article and a method of applying a coating to an article are also disclosed.
1 . A coating for an article, comprising:
a seal coat comprising self-healing particles disposed in a seal coat matrix, wherein the seal coat matrix is silicon carbide; and
a bond coat disposed on the seal coat, the bond coat comprising:
a matrix;
diffusive particles disposed in the matrix, and
gettering particles disposed in the matrix.
2 . The coating of claim 1 , wherein the seal coat further includes activator particles, the activator particles operable to hasten or improve viscous flow of the self-healing particles upon oxidation.
3 . The coating of claim 2 , wherein the seal coat comprises between about 0.1 and about 10 percent by weight activator particles.
4 . The coating of claim 3 , wherein the seal coat comprises between about 0.1 and about 5 percent by weight activator particles.
5 . The coating of claim 1 , wherein the self-healing particles exhibit diffusive behavior at lower temperatures than the diffusive particles.
6 . The coating of claim 1 , wherein the self-healing particles comprise at least one of silicon borocarbide, silicon boronitrocarbide, other carbides, aluminum nitride, borides, silicides, MAX phase particles, refractory metals, and combinations thereof.
7 . The coating of claim 1 , wherein the seal coat is between about 20 microns to about 200 microns thick.
8 . The coating of claim 1 , wherein the self-healing particles are encapsulated with a material that is relatively more inert with respect to oxidants than the material of the self-healing particles.
9 . The coating of claim 1 , wherein the coating is operable to be disposed on a ceramic matrix composite substrate.
10 . The coating of claim 9 , at least some of the seal coat constituents are infiltrated into the ceramic matrix composite.
11 . A coating for an article, comprising:
a bond coat disposed on a surface of the article, the bond coat comprising;
a matrix:
diffusive particles disposed in the matrix, and
gettering particles disposed in the matrix; and
a seal coat dispose between the surface of the article and the bond coat, the seal coat comprising:
a first layer of seal coat matrix material disposed on the surface of the article,
a layer of self-healing material disposed on the first layer of seal coat matrix material, wherein the self-healing material comprises at least one of silicon boronitrocarbide, aluminum nitride, silicides, MAX phase particles, refractory metals, and combinations thereof, and
a second layer of seal coat matrix material disposed on the layer of self-healing material.
12 . The coating of claim 11 , wherein the seal coat matrix is silicon carbide.
13 . The coating of claim 11 , wherein the coating is operable to be disposed on a ceramic matrix composite substrate.
14 . The coating of claim 13 , wherein at least some of the seal coat constituents are infiltrated into the ceramic matrix composite.
15 . A method of applying a coating to an article comprising:
applying a bond coat over a seal coat disposed on an article, the bond coat comprising, a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix, and the seal coat comprising a seal coat matrix material and a self-healing material, wherein the seal coat matrix is silicon carbide.
16 . The method of claim 15 , wherein the seal coat is applied by:
preparing a slurry comprising a carrier fluid, the seal coat matrix material, and the self-healing material;
applying the slurry to the article; and
curing the slurry to form the seal coat.
17 . The method of claim 16 , wherein the slurry further comprises activator particles, the activator particles operable to hasten or improve viscous flow of the self-healing particles upon oxidation.
18 . The coating of claim 1 , wherein the self-healing particles comprise at least one of silicon borocarbide, silicon boronitrocarbide, aluminum nitride, borides, silicides, MAX phase particles, refractory metals, and combinations thereof.