Slip and process for producing an aluminum diffusion layer

Patent metadata

Field	Value
Publication number	US-9845526-B2
Application number	US-201314384253-A
Country	US
Kind code	B2
Filing date	Mar 27, 2013
Priority date	Apr 3, 2012
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

The present invention relates to a slip for producing an aluminum diffusion layer which comprises an Al-containing powder and an Si-containing powder and a binder, the slurry further comprising an Al-containing powder the powder particles of which are coated with Si. The invention further relates to a process for producing an aluminum diffusion layer, comprising the following steps: providing a slurry according to any one of the preceding claims, applying the slurry to a component surface on which the aluminum diffusion layer is to be created, drying and/or curing by way of a heat treatment at a first temperature, and diffusion annealing at a second temperature.

First claim

What is claimed is:

1. A slurry for producing an aluminum diffusion layer, wherein the slurry comprises Al-containing powder, Si-containing powder, and a binder, the Al-containing powder comprising uncoated powder particles and powder particles which are coated with Si.

2. The slurry of claim 1 , wherein the Al-containing powder comprises technical-grade aluminum or Al alloys and/or the Si-containing powder comprises technical-grade silicon or Si alloys.

3. The slurry of claim 1 , wherein a proportion of silicon-coated aluminum powder particles as a percentage of a total number of aluminum powder particles is from 25% to 75% by weight or by volume.

4. The slurry of claim 1 , wherein the binder comprises at least one substance from the group of water, alcohols, glycol compounds, phosphates, phosphate-containing substances, and thickeners.

5. The slurry of claim 1 , wherein the binder comprises water, at least one glycol compound and at least one thickener.

6. The slurry of claim 1 , wherein the binder comprises a thickener which comprises one or more substances from the group of pectins, guar, carob seed flour, carrageenan, cellulose ethers, polyvinyl alcohol, and silicates.

7. A slurry for producing an aluminum diffusion layer, wherein the slurry comprises Al-containing powder, Si-containing powder, and a binder comprising water, at least one glycol compound and at least one thickener, the Al-containing powder comprising powder particles which are coated with Si.

8. The slurry of claim 7 , wherein a proportion of silicon-coated aluminum powder particles as a percentage of a total number of aluminum powder particles is from 25% to 75% by weight or by volume.

9. The slurry of claim 7 , wherein the binder comprises a thickener which comprises one or more substances from the group of pectins, guar, carob seed flour, carrageenan, cellulose ethers, polyvinyl alcohol, and silicates.

10. A process for producing an aluminum diffusion layer, wherein the process comprises applying a slurry to a component area on which the aluminum diffusion layer is to be produced, drying and/or curing the applied slurry with a heat treatment at a first temperature, followed by a diffusion heat treatment at a second temperature, and wherein the slurry comprises Al-containing powder, Si-containing powder, and a binder, the Al-containing powder comprising powder particles which are coated with Si.

11. The process of claim 10 , wherein the process further comprises blasting a surface to be treated with particles prior to application of the slurry.

12. The process of claim 11 , wherein the particles are aluminum oxide particles.

13. The process of claim 10 , wherein the first temperature is within a range from 100° C. to 300° C.

14. The process of claim 10 , wherein the first temperature is within a range from 120° C. to 220° C.

15. The process of claim 10 , wherein the second temperature is within a range from 800° C. to 1000° C.

16. The process of claim 10 , wherein the second temperature is within a range from 875° C. to 925° C.

17. The process of claim 14 , wherein the second temperature is within a range from 875° C. to 925° C.

18. The process of claim 10 , wherein the component on which the aluminum diffusion layer is to be produced is a component of a gas turbine or an aircraft engine.

19. The process of claim 18 , wherein the process involves repairing a gas turbine or an aircraft engine.

20. A process for producing an aluminum diffusion layer, wherein the process comprises applying the slurry of claim 1 to a component area on which the aluminum diffusion layer is to be produced, drying and/or curing the applied slurry with a heat treatment at a first temperature, followed by a diffusion heat treatment at a second temperature.

Assignees

• MTU Aero Engines AG

Inventors

• Stapel Martin
• Lopez Lavernia Natividad
• Pillhoefer Horst
• Morant Max
• Niegl Max

Classifications

• C23C10/20 Primary

  only one element being diffused · CPC title

• C23C10/18

  using liquids, e.g. salt baths, liquid suspensions · CPC title

• C23C10/60

  After-treatment · CPC title

• C23C10/02

  Pretreatment of the material to be coated (C23C10/04 takes precedence) · CPC title