Slurry and a coating method

Patent metadata

Field	Value
Publication number	US-9783880-B2
Application number	US-201314133969-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 19, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A slurry and a coating method are provided. The slurry includes, by weight, between 10% and 40% metal powder, between 10% and 15% activator, between 10% and 20% adhesive, between 10% and 20% thickener, up to 30% ceramic, and up to 25% binder. The coating method includes providing a slurry including, by weight, between 10% and 40% metal powder, between 10% and 15% activator, between 10% and 20% adhesive, between 10% and 20% thickener, up to 30% ceramic, and up to 25% organic polymer binder, providing a substrate, applying the slurry over a surface of the substrate to form a slurry coating, drying the slurry coating over the substrate, baking the substrate and the slurry coating, and curing the slurry coating over the substrate. The curing the slurry coating over the substrate transfers metal elements of the metal powder in the slurry to the substrate to form a coating on the substrate.

First claim

What is claimed is:

1. A slurry for forming a diffusion coating on a surface of a component, the slurry comprising, by weight:
between 10% and 40% metal powder;
between 10% and 15% activator, exclusive of adhesive;
between 10% and 20% adhesive, exclusive of activator;
between 10% and 20% thickener, exclusive of ceramic;
up to 30% ceramic, the ceramic being present, exclusive of thickener; and
up to 25% binder, the binder being present, exclusive of adhesive.

2. The slurry of claim 1 , wherein the component comprises a superalloy.

3. The slurry of claim 1 , wherein the metal powder comprises a metallic aluminum alloy.

4. The slurry of claim 1 , wherein the activator comprises a halide activator.

5. The slurry of claim 4 , wherein the halide activator is selected from the group consisting of methyl chloride, ammonium chloride, ammonium fluoride, and ammonium bromide.

6. The slurry of claim 1 , wherein the adhesive is selected from the group consisting of a wet adhesive and a polyether.

7. The slurry of claim 6 , wherein the polyether further comprises polyethylene oxide.

8. The slurry of claim 1 , wherein the thickener comprises alumina.

9. The slurry of claim 1 , wherein increasing an amount of the thickener increases a viscosity of the slurry.

10. The slurry of claim 1 , wherein increasing an amount of the adhesive increases a viscosity of the slurry.

11. The slurry of claim 1 , wherein the ceramic comprises a ceramic powder selected from the group consisting of zirconium oxide, boron nitride, titanium dioxide, and aluminum nitride.

12. The slurry of claim 1 , wherein the binder comprises an organic polymer.

13. The slurry of claim 1 , wherein increasing an amount of the binder decreases a viscosity of the slurry.

14. A slurry for forming a diffusion coating on a surface of a component, the slurry comprising, by weight:
between 10% and 40% Cr—Al powder;
between 10% and 15% activator, exclusive of polyethylene oxide;
between 10% and 20% polyethylene oxide, exclusive of activator;
between 10% and 20% thickener, exclusive of ceramic;
up to 30% ceramic, the ceramic being present, exclusive of thickener; and
up to 25% organic polymer binder, the organic polymer binder being present, exclusive of adhesive.

15. A coating method, comprising:
providing a slurry comprising the composition of claim 1 ;
providing a substrate;
applying the slurry over a surface of the substrate to form a slurry coating;
drying the slurry coating over the substrate;
baking the substrate and the slurry coating; and
curing the slurry coating over the substrate;
wherein curing the slurry coating over the substrate transfers metal elements of the metal powder in the slurry to the substrate to form a coating on the substrate.

16. The coating method of claim 15 , further comprising increasing an amount of the adhesive in the slurry to increase a viscosity of the slurry and a rate of movement of the slurry over the surface of the substrate.

17. The coating method of claim 15 , wherein baking the substrate and the slurry coating further comprises burning off the binder and the adhesive.

18. The coating method of claim 17 , further comprising removing the ceramic from the slurry coating after baking the substrate and the slurry coating.

19. The coating method of claim 18 , wherein removing the ceramic from the slurry coating further comprises rinsing the substrate and the slurry coating with a liquid.

20. The coating method of claim 15 , further comprising forming the coated substrate without post heat-treating the substrate.

Assignees

• Gen Electric

Inventors

• Lin Dechao
• Bucci David Vincent

Classifications

• C23C10/60 Primary

  After-treatment · CPC title

• C23C12/00 Primary

  Solid state diffusion of at least one non-metal element other than silicon and at least one metal element or silicon into metallic material surfaces · CPC title

• C23C10/20

  only one element being diffused · CPC title

• C23C10/32

  Chromising · CPC title

• C23C10/56

  and at least aluminium · CPC title