Hybrid blade for turbomachines

Patent metadata

Field	Value
Publication number	US-2017241272-A1
Application number	US-201615280653-A
Country	US
Kind code	A1
Filing date	Sep 29, 2016
Priority date	Oct 6, 2015
Publication date	Aug 24, 2017
Grant date	—

Abstract

Disclosed is a blade for a turbomachine, comprising an outer shell and an inner core which is at least partially enclosed by the outer shell and has a higher porosity than the outer shell. The outer shell is formed by a ceramic body or a body made of a ceramic matrix composite material, and the inner core is formed by a fiber-reinforced ceramic or a fiber-reinforced ceramic matrix composite material.

First claim

What is claimed is:

1 . A blade for a turbomachine, wherein the blade comprises an outer shell and an inner core which is at least partially enclosed by the outer shell and has a higher porosity than the outer shell, the outer shell being formed by a ceramic body or a body of a ceramic matrix composite material and the inner core being formed by a fiber-reinforced ceramic or a fiber-reinforced ceramic matrix composite material.

2 . The blade of claim 1 , wherein the outer shell is formed by a compact ceramic body and the inner core is formed by a porous fiber-reinforced ceramic.

3 . The blade of claim 1 , wherein the ceramic matrix composite material is a ceramic/ceramic composite material or a composite of a ceramic and one or more intermetallic compounds.

4 . The blade of claim 1 , wherein the porosity of the outer shell is not higher than 5 vol %, and/or the porosity of the inner core ranges from 10 to 30 vol %.

5 . The blade of claim 4 , wherein the porosity of the outer shell is not higher than 1 vol %, and/or the porosity of the inner core ranges from 15 to 23 vol %.

6 . The blade of claim 1 , wherein the ceramic material by which the ceramic body of the outer shell or the body of the ceramic matrix composite material of the outer shell is formed comprises at least one material which is selected from HfB 2 , ZrB 2 , HfN, ZrN, TiC, TiN, ThO 2 , TaC and mixtures of at least one of the aforementioned materials with SiC.

7 . The blade of claim 1 , wherein the ceramic material by which the ceramic of the core or the ceramic matrix composite material of the core is formed comprises at least one material which is selected from HfB 2 , ZrB 2 , HfN, ZrN, TiC, TiN, ThO 2 , TaC and mixtures of at least one of the aforementioned materials with SiC.

8 . The blade of claim 1 , wherein the fibers of the fiber-reinforced ceramic or of the fiber-reinforced matrix composite material comprise at least one material which is selected from HfB 2 , ZrB 2 , HfN, ZrN, TiC, TiN, ThO 2 , TaC and mixtures of at least one of the aforementioned materials with SiC.

9 . A method for producing a blade of a turbomachine, wherein the method comprises forming an outer shell of the blade from a ceramic body or from a body of ceramic matrix composite material and subsequently using the outer shell thus formed as a mold for an inner core, the inner core being formed by introducing a flowable mixture into the outer shell, and forming the flowable mixture and the outer shell into the blade by a heat treatment.

10 . The method of claim 9 , wherein the outer shell is produced by a generative method.

11 . The method of claim 10 , wherein the outer shell is produced by a three-dimensional printing method.

12 . The method of claim 9 , wherein the outer shell is produced by a wax or plastic melting method.

13 . The method of claim 9 , wherein a ceramic slurry, which is formed into a green body, is used for producing the outer shell, the green body being used directly or after a heat treatment as a mold for the inner core.

14 . The method of claim 9 , wherein the flowable mixture comprises a starting material comprising from 10 to 30 vol % of fibers and from 20 to 30 vol % of one or more pore-forming agents, the remainder being ceramic material and/or one or more intermetallic compounds.

15 . The method of claim 14 , wherein the flowable mixture comprises a starting material comprising from 15 to 25 vol % of fibers.

16 . The method of claim 14 , wherein the starting material is mixed with a solvent to form the flowable mixture.

17 . The method of claim 16 , wherein the solvent comprises hexane and/or distilled water.

18 . The method of claim 9 , wherein the flowable mixture is homogenized before introduction into the outer shell.

19 . The method of claim 9 , wherein the ceramic material for at least one constituent from a group that comprises the ceramic slurry and the ceramic material of the flowable mixture and the fibers of the flowable mixture, is selected from at least one material selected from HfB 2 , ZrB 2 , HfN, ZrN, TiC, TiN, ThO 2 , TaC and mixtures of at least one of the aforementioned materials with SiC.

20 . The method of claim 9 , wherein the outer shell and the flowable mixture in the outer shell are aged at a temperature ranging from about 1300° C. to about 1700° C. for at least about 2 hours.

Assignees

• MTU Aero Engines AG

Inventors

• Borto Artur
• Kapusta Piotr
• Luczyniec Dawid

Classifications

• B22F5/04

  of turbine blades · CPC title

• C04B2111/00413

  Materials having an inhomogeneous concentration of ingredients or irregular properties in different layers · CPC title

• F01D5/282 Primary

  Selecting composite materials, e.g. blades with reinforcing filaments · CPC title

• C04B35/5607

  based on refractory metal carbides · CPC title

• F05D2300/20

  Oxide or non-oxide ceramics · CPC title