Yttrium aluminum garnet based thermal barrier coatings

Patent metadata

Field	Value
Publication number	US-2016257618-A1
Application number	US-201615040871-A
Country	US
Kind code	A1
Filing date	Feb 10, 2016
Priority date	Feb 10, 2015
Publication date	Sep 8, 2016
Grant date	—

Abstract

Embodiments of a microstructure that allows arrest of contaminant infiltration includes an inter layer and at least one highly reactive ceramic layer. The inter layer is not reactive to an infiltrating reactive species. The HRC layer includes materials that react with a reactive contaminant species to slow or arrest infiltration of such contaminant species.

First claim

What is claimed is:

1 . A method of making thermal barrier coatings having improved resistance to CMAS:
wherein the thermal barrier coatings comprise YAG.

2 . The method of claim 1 , wherein inherent inert properties of YAG provide some, most or all of the CMAS resistance/blocking.

3 . The method of claim 2 , wherein improved resistance to CMAS is further provided by promoting CMAS blocking reactions only in cracks, pores, and pore channels of the thermal barrier coatings.

4 . The method of claim 3 , wherein highly reactive ceramics (HRC) are selectively deposited into the cracks and porous locations and near surface locations of YAG.

5 . The method of claim 4 , wherein the HRC comprise yttria, and one or more of an oxide of the lanthanides (La, Ce, Pr, Nd, Pm, SM, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu).

6 . The method of claim 2 , further comprising increasing the Y content of YAG thermal barrier coatings to produce more reactive coatings that will react with CMAS to stop its infiltration.

7 . The method of claim 6 , wherein the thermal barrier coatings are made with YAG based compositions wherein the amount of Y relative to Al in YAG is increased to increase the amount of YAM and/or to increase the amount of YAP in the thermal barrier coatings.

8 . The method of claim 7 , wherein the thermal barrier coatings comprise a multiphase coating that comprises more than one of YAG, YAM, and YAP.

9 . The method claim 8 , wherein thermal barrier coatings enriched with Yttrium comprise more YAG with YAM than YAP.

10 . The method of claim 7 , wherein the thermal barrier coatings enriched with Yttrium comprise more YAG with YAM than YAP.

11 . The method of claim 1 , wherein improved resistance to CMAS is further provided by promoting CMAS blocking reactions only in cracks, pores and pore channels of the thermal barrier coatings.

12 . A microstructure that allows arrest of contaminant infiltration comprising:
at least one inter layer, wherein inter layer is not very reactive to an infiltrating reactive species; and at least one highly reactive ceramic layer (HRC layer), wherein the HRC layer comprises materials that react with a reactive contaminant species to slow or arrest infiltration of such reactive contaminant species.

13 . The microstructure of claim 12 , wherein the at least one HRC layer comprises one or more oxides of Y and/or one or more oxides of any lanthanide (La, Ce, Pr, Nd, Pm, SM, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu).

14 . The microstructure of claim 12 , comprising more than one inert phase, or more than one reactive phase, or both more than one inert phase and more than one reactive phase.

15 . The microstructure of claim 12 , wherein the microstructure comprises a layer of Y 2 O 3 between layers of YAG and a layer of Gd 2 O 7 Zr 2 between layers of YAG.

16 . The microstructure of claim 12 , wherein the microstructure comprises a first layer of Y 2 O 3 +Gd 2 O 7 Zr 2 between layers of YAG and a second layer of Y 2 O 3 +Gd 2 O 7 Zr 2 between layers of YAG.

17 . A thermal barrier coating comprising:
a YAG-based composition, wherein the composition is on the Y 2 O 3 rich side of the Y 2 O 3 —Al 2 O 3 phase diagram relative to stoichiometric YAG.

18 . The thermal barrier coating of claim 17 , further comprising a multiphase coating that comprises more than one of YAG, YAM, and YAP.

Assignees

• Univ Connecticut

Inventors

• Jordan Eric H
• Gell Maurice
• Kumar Rishi
• Jiang Chen

Classifications

• C01F17/34

  Aluminates, e.g. YAlO3 or Y3-xGdxAl5O12 · CPC title

• B32B18/00

  Layered products essentially comprising ceramics, e.g. refractory products · CPC title

• C04B2237/343

  Alumina or aluminates · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C04B2237/348

  Zirconia, hafnia, zirconates or hafnates · CPC title