Component of a molybdenum alloy and method for forming an oxidation protection layer therefor

Patent metadata

Field	Value
Publication number	US-2017241271-A1
Application number	US-201715431925-A
Country	US
Kind code	A1
Filing date	Feb 14, 2017
Priority date	Feb 24, 2016
Publication date	Aug 24, 2017
Grant date	—

Abstract

Disclosed is a method for improving the high-temperature stability of a component, in particular a blade of a turbomachine, formed at least partially from a molybdenum alloy that, besides molybdenum, silicon, boron and titanium, comprises iron and/or yttrium. The method comprises depositing a diffusion barrier layer formed from technically pure molybdenum or tungsten or being an alloy based on molybdenum and/or tungsten at least on an outer surface, which comprises the molybdenum alloy, of the component, and depositing silicon on the diffusion barrier layer to form molybdenum silicides and/or tungsten silicides.

First claim

What is claimed is:

1 . A method for improving the high-temperature stability of a component which is formed at least partially from a molybdenum alloy that, besides molybdenum, silicon, boron and titanium, comprises iron and/or yttrium, wherein the method comprises depositing at least on an outer surface, which comprises the molybdenum alloy, of the component a diffusion barrier layer formed from technically pure molybdenum or tungsten or being an alloy based on molybdenum and/or tungsten, and depositing silicon on the diffusion barrier layer after deposition of the diffusion barrier layer to form molybdenum silicides and/or tungsten silicides.

2 . The method of claim 1 , wherein the component is a blade of a turbomachine.

3 . The method of claim 1 , wherein the alloy based on molybdenum and/or tungsten comprises niobium and/or tantalum.

4 . The method of claim 1 , wherein boron is deposited with the silicon in order to form molybdenum boride and/or tungsten boride and/or molybdenum borosilicides and/or tungsten borosilicides.

5 . The method of claim 3 , wherein boron is deposited with the silicon to form molybdenum boride and/or tungsten boride and/or molybdenum borosilicides and/or tungsten borosilicides.

6 . The method of claim 1 , wherein the deposition of the diffusion barrier layer is carried out by physical vapor deposition.

7 . The method of claim 7 , wherein the deposition of the diffusion barrier layer is carried out by sputtering.

8 . The method of claim 1 , wherein the deposition of the silicon is carried out by chemical vapor deposition.

9 . The method of claim 1 , wherein the method further comprises carrying out a heat treatment to form the molybdenum silicides and/or tungsten silicides after deposition of the silicon.

10 . The method of claim 1 , wherein the method further comprises carrying out a heat treatment in an atmosphere containing oxygen after formation of the molybdenum silicides and/or tungsten silicides, to form an oxide layer.

11 . The method of claim 9 , wherein the method further comprises carrying out a heat treatment in an atmosphere containing oxygen after formation of the molybdenum silicides and/or tungsten silicides, to form an oxide layer.

12 . The method of claim 1 , wherein the diffusion barrier layer comprises at least 90 wt % of molybdenum.

13 . The method of claim 1 , wherein the diffusion barrier layer comprises no tungsten.

14 . The method of claim 1 , wherein the diffusion barrier layer comprises no molybdenum.

15 . The method of claim 1 , wherein the diffusion barrier layer comprises both molybdenum and tungsten.

16 . The method of claim 1 , wherein the diffusion barrier layer is formed from technically pure molybdenum or tungsten

17 . A component for high-temperature applications, wherein the component is formed at least partially from a molybdenum alloy that, besides molybdenum, silicon, boron and titanium, comprises iron and/or yttrium, wherein a diffusion barrier layer formed from technically pure molybdenum or tungsten or being an alloy based on molybdenum and/or tungsten is arranged at least on a region, which comprises the molybdenum alloy, of the component, and wherein a layer which comprises molybdenum silicides and/or tungsten silicides is arranged on the diffusion barrier layer.

18 . The component of claim 17 , wherein an oxide layer is arranged on the layer comprising molybdenum silicides and/or tungsten silicides.

19 . The component of claim 17 , wherein the component is a component of a turbomachine.

20 . The component of claim 17 , wherein the component is a guide vane or rotor blade of a turbomachine.

Assignees

• MTU Aero Engines AG

Inventors

• Fried Markus
• Smarsly Wilfried
• Broetzner Andreas

Classifications

• C22C27/04 Primary

  Alloys based on tungsten or molybdenum · CPC title

• F01D9/02

  Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)} · CPC title

• C22C30/00

  Alloys containing less than 50% by weight of each constituent · CPC title

• F05D2230/314

  by chemical vapour deposition · CPC title

• C23C16/38

  Borides · CPC title