CN116605904A

CN116605904A - Pyrochlore/defective fluorite zirconates

Info

Publication number: CN116605904A
Application number: CN202211525827.5A
Authority: CN
Inventors: A·森古普塔; M·纳亚克; S·库马; V·拉朱·S
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2022-02-16
Filing date: 2022-11-30
Publication date: 2023-08-18

Abstract

A composition is provided that includes a rare earth doped zirconium/hafnium oxide having a defective fluorite structure or pyrochlore structure. The rare earth doped zirconium/hafnium oxide has the formula: (Ln) ¹ _a Ln ² _a Ln ³ _a Ln ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇ Wherein Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ And Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; a is 0.2 or 0.25; b is 0.2 when a is 0.2, and b is 0 when a is 0.25; and M is Zr, hf or mixtures thereof. Methods of forming a coating comprising the composition and the resulting coated parts are also provided.

Description

Pyrochlore/defective fluorite zirconates

PRIORITY INFORMATION

The present application claims priority from indian provisional patent application No. 202211008138 filed on day 2022, month 2 and 16.

Technical Field

The present application relates broadly to ultra low thermal conductivity pyrochlore/defective fluorite zirconate (pyrochlore/defect fluorite zirconates). More particularly, the present application relates generally to compositions suitable for use in coating systems on components exposed to high temperature environments (e.g., hot gas flow paths through a gas turbine engine).

Background

The use of thermal barrier coatings on components such as combustors, high Pressure Turbine (HPT) blades, and gas turbine engine vanes (vane) is increasing. Generally, the thermal insulation of TBCs enables such components to withstand higher operating temperatures, increases component durability, and improves engine reliability. In order for a TBC to remain effective throughout the planned life cycle of the component it protects, it is desirable that the TBC have a low thermal conductivity throughout the life cycle of the component, including a high Wen Piaoyi (high temperature excursion). In addition, it is desirable for TBCs to have high toughness, thereby reducing damage to the rotating, combustor, and static turbine components (e.g., turbine nozzles) of the HPT from erosion and shock. Low thermal conductivity TBCs can improve efficiency by reducing heat loss and potentially allowing higher temperature operation.

Current TBC materials 8YSZ are known for their high toughness and high thermal conductivity. Low thermal conductivity components such as 55YSZ lack high toughness. Accordingly, further improvements in TBC technology are desired, particularly when the TBC is used for thermal insulation for components of more demanding engine designs.

Disclosure of Invention

The present application provides a composition comprising: a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, wherein the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _a Ln ² _a Ln ³ _a Ln ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇ ，

wherein, the liquid crystal display device comprises a liquid crystal display device,

Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ and Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78;

a is 0.2 or 0.25;

b is 0.2 when a is 0.2, and b is 0 when a is 0.25; and

m is Zr, hf or a mixture thereof.

Preferably, in the above formula, a is 0.2 such that the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _0.2 Ln ² _0.2 Ln ³ _0.2 Ln ⁴ _0.2 Ln ⁵ _0.2 ) ₂ M ₂ O ₇ ，

Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ and Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; and

m is Zr, hf or a mixture thereof.

Preferably, in the above formula, a is 0.25 and b is 0, such that the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _0.25 Ln ² _0.25 Ln ³ _0.25 Ln ⁴ _0.25 ) ₂ M ₂ O ₇ ，

Ln ¹ 、Ln ² 、Ln ³ and Ln ⁴ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; and

m is Zr, hf or a mixture thereof.

Preferably, M is 50 atomic% to 100 atomic% Zr, more preferably, M is 95 atomic% to 100 atomic% Zr, still more preferably, M consists of Zr.

Preferably, in the above formula, ln ¹ And Ln ² Is a different rare earth element selected from Tb, dy, Y, ho, er, tm, yb and Lu.

Preferably, in the above formula, ln ³ And Ln ⁴ Is a different rare earth element selected from La, ce, pr, nd, pm, sm, eu and Gd.

Preferably, the composition has a thermal conductivity of 0.5W/m-K to 1.5W/m-K at 1000℃in a 95-100% dense disk as measured by laser flash method according to ASTM E1461-13.

Preferably, the composition is selected from the following:

(Nd _0.2 Eu _0.2 Y _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Tb _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Gd _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Y _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 La _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Y _0.2 Dy _0.2 Er _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Er _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.25 Eu _0.25 Ho _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ ；

(Nd _0.25 Eu _0.25 Y _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ ；

(Sm _0.25 Eu _0.25 Ho _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ the method comprises the steps of carrying out a first treatment on the surface of the And mixtures thereof.

The present application also provides a coated member, wherein the coated member comprises:

a substrate having a surface; and

a thermal barrier coating on the surface, wherein the thermal barrier coating comprises a layer comprising the composition of the present application.

a substrate having a surface; and

a thermal barrier coating on the surface, wherein the thermal barrier coating comprises a layer comprising a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, the layer having a thermal conductivity of 0.5W/m "K to 1.5W/m" K at 1000 ℃ in a 95-100% dense disk as measured by laser flash method according to ASTM E1461-13.

Preferably, in the coated part, the layer has an indentation fracture toughness in the 95-100% dense disk of 2MPa-m ^0.5 ～3MPa-m ^0.5 。

Preferably, in the coated component, the rare earth doped zirconium/hafnium oxide comprises 4 or 5 different rare earth elements each present in substantially equal atomic percentages.

Preferably, in the coated member, the layer comprises a single phase rare earth doped zirconium/hafnium oxide having a defect-fluorite structure.

Preferably, in the coated member, the layer comprises a single phase rare earth doped zirconium/hafnium oxide having a pyrochlore structure.

Preferably, in the coated member, the rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or pyrochlore structure has the formula:

(Ln ¹ _a Ln ² _a Ln ³ _a Ln ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇ ，

a is 0.2 or 0.25;

b is 0.2 when a is 0.2, and b is 0 when a is 0.25; and

m is Zr, hf or a mixture thereof.

Preferably, M is 95 atomic% to 100 atomic% Zr in the coated member.

In another aspect, the present application also provides a method of forming a rare earth doped zirconium/hafnium oxide, the method comprising:

combining 4 or 5 different rare earth zirconium/hafnium oxides to form rare earth doped zirconium/hafnium oxides having a defect-fluorite structure or pyrochlore structure,

wherein the first rare earth oxide contains a first rare earth element, the first atomic radius ratio of the first rare earth element to Zr is 1.35-1.45, the second rare earth oxide contains a second rare earth element, the second atomic radius ratio of the second rare earth element to Zr is 1.35-1.45, the third rare earth oxide contains a third rare earth element, the third atomic radius ratio of the third rare earth element to Zr is 1.46-1.78, the fourth rare earth oxide contains a fourth rare earth element, the fourth atomic radius ratio of the fourth rare earth element to Zr is 1.46-1.78,

wherein each of the different rare earth zirconium/hafnium oxides is present at substantially equal atomic weights of their respective rare earth elements.

Drawings

A full and enabling disclosure of the present application, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 is a cross-sectional side view of an exemplary coated component; and

FIG. 2 is a schematic cross-sectional view of an exemplary gas turbine engine according to various embodiments of the present subject matter.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the application.

Detailed Description

Definition of the definition

As used herein, the term "exemplary" means "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. In addition, all embodiments described herein should be considered exemplary unless specifically indicated otherwise.

The term "gas turbine engine" refers to an engine having a turbine as all or part of its power source. Exemplary gas turbine engines include turbofan engines, turboprop engines, turbojet engines, turboshaft engines, and the like, as well as hybrid versions of one or more of these engines. The term "turbomachinery" or "turbomachinery" refers to a machine that includes one or more compressors, a heat-generating section (e.g., a combustion section), and one or more turbines that together produce a torque output.

In the present application, when a layer is described as being "on" or "over" another layer or substrate, it is to be understood that the layers can either be in direct contact with each other or have another layer or feature between the layers unless expressly stated to the contrary. Thus, these terms merely describe the relative position of the layers to one another and do not necessarily mean "on top of … …" because the relative position above or below depends on the orientation of the device with respect to the viewer.

In the present application, chemical elements are discussed using their common chemical abbreviations, such as those common on the periodic table of elements. For example, hydrogen is represented by its common chemical abbreviation H; helium is represented by its common chemical abbreviation He; etc.

As used herein, "Ln" refers to a rare earth element or a mixture of rare earth elements. More specifically, "Ln" refers to rare earth elements in scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or mixtures thereof.

As used herein, the term "substantially free" is to be understood as either completely free of the recited ingredient or containing trace amounts of the same ingredient. "traces" are quantitative levels of chemical components that are barely detectable and provide no benefit to the functional or aesthetic properties of the subject composition (subject composition). The term "substantially free" also includes complete absence.

As used herein, the term "substantially equal" should be understood to include minor trace changes at quantitative levels that are barely detectable and provide no benefit to the functional or aesthetic properties of the subject composition. The term "substantially equal" also includes perfect equality.

Reference now will be made in detail to embodiments of the application, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the application, not limitation of the application. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope of the application. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a further embodiment. Accordingly, it is intended that the present application cover such modifications and variations as come within the scope of the appended claims and their equivalents.

Compositions based on rare earth-zirconium/hafnium oxides having pyrochlore or defective fluorite structures and coatings formed from the compositions are generally disclosed. These compositions and coatings may have relatively low thermal conductivities (e.g., 0.5W/m-K to 1.5W/m-K at 1000℃, such as 0.5W/m-K to 1.4W/m-K at 1000℃ in 95-100% dense disk (dense puck) as measured by laser flash according to ASTM E1461-13). In general, these compositions are useful for forming films having ultra-low thermal conductivity and suitable toughness (e.g., indentation fracture toughness in 95-100% dense disks of 2 MPa-m) ^0.5 ～3MPa-m ^0.5 ) Is included in the TBC layer of (C).

In one particular embodiment, the TBC layer may have a single phase (i.e., a pyrochlore structure or a defect-fluorite structure). Thus, the resulting TBC will allow for a higher component surface temperature and/or reduced coating thickness for the same surface temperature. Reduced TBC thickness (particularly in applications such as combustors where a relatively thick TBC is required) will result in significant cost reduction as well as weight benefits.

The composition generally comprises a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore-structure. In one embodiment, the rare earth doped zirconium/hafnium oxide has the formula shown in formula 1:

formula 1: (Ln) ¹ _a Ln ² _a Ln ³ _a Ln ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇

Wherein Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ And Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio of 1.46 to 1.78, and Ln ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; a is 0.2 or 0.25; b is 0.2 when a is 0.2, and b is 0 when a is 0.25; m is Zr, hf or a mixture thereof.

In general, ln ¹ And Ln2 are each a different rare earth element, which forms a defective fluorite Ln ₂ Zr ₂ O ₇ (e.g., tb, dy, Y, ho, er, tm, yb and Lu) and/or forming defective fluorite Ln ₂ Hf ₂ O ₇ (e.g., dy, Y, ho, er, tm, yb and Lu). In a particular embodiment, ln ¹ And Ln ² Each of which is a different rare earth element selected from Tb, dy, Y, ho, er, tm, yb and Lu.

Alternatively, ln ³ And Ln ⁴ Each of which is a different rare earth element, which forms pyrochlore Ln ₂ Zr ₂ O ₇ (e.g., la, ce, pr, nd, pm, sm, eu and Gd) and/or pyrochlore Ln formation ₂ Hf ₂ O ₇ (e.g., la, ce, pr, nd, pm, sm, eu, gd and Tb). In a particular embodiment, ln ¹ And Ln ² Is a different rare earth element selected from La, ce, pr, nd, pm, sm, eu, gd and Tb.

In a particular embodiment, a is 0.2 such that the rare earth doped zirconium/hafnium oxide has the formula shown in formula 2:

formula 2: (Ln) ¹ _0.2 Ln ² _0.2 Ln ³ _0.2 Ln ⁴ _0.2 Ln ⁵ _0.2 ) ₂ M ₂ O ₇

Wherein Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ And Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio of 1.46 to 1.78, and Ln ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; m is Zr, hf or a mixture thereof. In such an embodiment, ln ⁵ And M may have a second atomic radius ratio of 1.35 to 1.45 or 1.46 to 1.78.

In another particular embodiment, a is 0.25 and b is 0, such that the rare earth doped zirconium/hafnium oxide has the formula shown in formula 3:

formula 3: (Ln) ¹ _0.25 Ln ² _0.25 Ln ³ _0.25 Ln ⁴ _0.25 ) ₂ M ₂ O ₇

Wherein Ln ¹ 、Ln ² 、Ln ³ And Ln ⁴ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio of 1.46 to 1.78, and Ln ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; m is Zr, hf or a mixture thereof.

As described above, due to ZrO ₂ And HfO ₂ Chemical similarity of (2) and Zr ⁴⁺ () And Hf ⁴⁺ (/>) Since M in any of the formulae 1, 2 or 3 may be Zr, hf or a mixture thereof. Thus, M may be 0 atomic% to 100 atomic% Zr. Conversely, M may be 0 atomic% to 100 atomic% Hf. However, in particular embodiments, zr may form half or more of the atomic percent of M, such that M is 50 atomic% to 100 atomic%Zr. In a particular embodiment, zr is the major component of M (e.g., M is 95 atomic% to 100 atomic% Zr). For example, in certain embodiments, M may consist of Zr (i.e., M is 100 atomic% Zr).

Particularly suitable compositions of rare earth doped zirconium/hafnium oxides having a defect-fluorite structure or pyrochlore structure may include, but are not limited to:

(Nd _0.2 Eu _0.2 Y _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Tb _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Gd _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Y _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 La _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Y _0.2 Dy _0.2 Er _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Er _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.25 Eu _0.25 Ho _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ ；

(Nd _0.25 Eu _0.25 Y _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ ；

(Sm _0.25 Eu _0.25 Ho _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ the method comprises the steps of carrying out a first treatment on the surface of the Or a mixture thereof.

As noted above, compositions of rare earth doped zirconium/hafnium oxides having a defect-fluorite structure or pyrochlore structure are particularly useful as layers in thermal barrier coatings on components.

For example, referring to FIG. 1, an exemplary coated component 100 is shown formed from a substrate 102 having a surface 103 and a coating system 106 thereon. In general, coating system 106 includes bond coat layer 104 on surface 103 of substrate 102 and TBC 108 on bond coat layer 104. In the embodiment shown, the bond coat 104 is directly on the surface 103 without any layer in between. Bond coat materials widely used in TBC systems may include, but are not limited to: an oxidation resistant overlay coating, such as MCrAlX (where M is iron, cobalt and/or nickel, and X is yttrium or other rare earth element), and an oxidation resistant diffusion coating, such as a diffusion aluminide containing aluminum intermetallic compounds.

The substrate 102 may be any suitable material, for example, a metal, such as steel or a superalloy (e.g., a nickel-based superalloy, a cobalt-based superalloy, or an iron-based superalloy, such as Rene N5, N500, N4, N2, IN718, hastelloy X, or Haynes 188) or other suitable material for withstanding high temperatures. The coating system 106 may be disposed along one or more portions of the substrate 102 or substantially on the entire exterior of the substrate 102. In particular embodiments, the coating system 106 can have a total thickness of 50 μm (e.g., microns or μm) to 2500 μm, such as 100 μm to 700 μm.

TBC 108 may be formed from a plurality of individual layers 114. In one embodiment, at least one of the layers 114 of the TBC 108 comprises a layer comprising a composition comprising a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, such as the formula of formula 1. For example, at least one of the layers 114 of the TBC 108 may comprise at least 80 wt.% of a composition of a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, such as a formula having formula 1. In one embodiment, at least one of the layers 114 of the TBC 108 may comprise 90 wt% to 100 wt% of a composition of a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, such as that having formula 1.

In particular embodiments, each of the layers 114 of the TBC 108 may have a layer thickness of 25 μm to 100 μm (e.g., 25 μm to 50 μm).

One or more of the individual layers 114 may be formed of a stable ceramic capable of withstanding relatively high temperature gradients so that the coated metal component may be operated at gas temperatures above the melting point of the metal. For example, the stable ceramic material may be one or more of the following: yttrium Stabilized Zirconia (YSZ) and other rare earth stabilized zirconia compositions, mullite (3 Al) ₂ O ₃ -2SiO ₂ ) Alumina, ceria (CeO) ₂ ) Lanthanum zirconate, rare earth oxide (e.g. La ₂ O ₃ 、Nb ₂ O ₅ 、Pr ₂ O ₃ 、CeO ₂ ) And metal-glass composites and combinations thereof (e.g., alumina and YSZ, or ceria and YSZ). In addition to having high temperature stability, YSZ has a good combination of high toughness and chemical inertness, and the coefficient of thermal expansion of YSZ is quite suitably matched to that of the coated metal part.

Each individual layer 114 may be formed by any suitable process. For example, one or more of the individual layers 114 may be formed by air-plasma spraying (APS), suspension Plasma Spraying (SPS), solution Precursor Plasma Spraying (SPPS), electron Beam Physical Vapor Deposition (EBPVD), high Velocity Oxygen Fuel (HVOF), electrostatic Spray Assisted Vapor Deposition (ESAVD), and direct vapor deposition.

In one embodiment, TBC 108 may comprise a layer based on YSZ (e.g., 8 YSZ) closest to substrate 102 (e.g., directly on bond coat 104, if present). Thus, yttrium stabilized zirconia can form a barrier coating between a substrate and a layer comprising a rare earth doped zirconium/hafnium oxide composition having a defect-fluorite structure or pyrochlore structure, such as the formula of formula 1.

The coated component 100 is particularly suitable for use as a component present in high temperature environments, such as those found in gas turbine engines, for example, combustor components, turbine blades, shrouds, nozzles, heat shields, and vanes. In particular, the coated component 100 may be a component located within a hot gas flow path of a gas turbine such that the coating system 106 forms a thermal barrier for the underlying substrate 102 to protect the component 100 within the gas turbine when exposed to the hot gas flow path.

Coatings comprising rare earth doped zirconium/hafnium oxides can be obtained by using powder raw materials synthesized by: in a suitable solvent (e.g., aqueous or organic or a combination), a suitable metal (Ln, hf, zr) precursor (organic (e.g., metal alkoxides such as propoxide, butoxide, isopropoxide, ethoxide, tetraethoxide, or triethoxide) or inorganic (e.g., metal chlorides, oxychlorides, nitrates, oxynitrates, carbonates)) is used, synthesized by wet chemical synthetic routes. Suitable organic solvents may include, but are not limited to, isopropanol, ethanol, butanol, or ethylene glycol monobutyl ether. Other components in the wet chemical route may include organic acids (e.g., citric acid or acetic acid), inorganic acids (e.g., HCl or HNO) ₃ ) An organic base (e.g. diethylamine, triethylamine or diethylenetriamine) or an inorganic base (e.g. NaOH or NH) ₄ OH). Viscosity modifiers (e.g., glycerol, ethylene glycol, ethyl acetate, or polyethylene glycol) may also be present. Non-limiting examples of wet chemical routes include sol-gel, polymer precursor or gel-combustion, hydrothermal or solvothermal, co-precipitation hydrothermal combinations, and co-precipitation molten salt square combinations. In these methods, the initial treatment may be performed at room temperature to about 200 ℃, followed by a heat treatment at a low temperature of 500 ℃ to 1000 ℃ (which is relatively low compared to the solid state synthetic route) may result in the formation of a final composition having a low grain size (e.g., within a nanometer size, such as 10nm to 100 nm). The powder particles of the compositions obtained in this way can be sprayed by the above-described method to obtain a final coating with a fine-grained microstructure (for example, 2-10 μm), which, thanks to the inherent resistance to sintering, can be cycled through heatingThe fine-grained microstructure is maintained during the ring.

FIG. 2 is a schematic cross-sectional view of a gas turbine engine according to an exemplary embodiment of the application. More specifically, for the embodiment of FIG. 2, the gas turbine engine is a high bypass turbofan engine 10, referred to herein as "turbofan engine 10". As shown in fig. 2, turbofan engine 10 defines an axial direction a (extending parallel to longitudinal axis 12 for reference) and a radial direction R. Generally, turbofan engine 10 includes a fan section 14 and a core turbine engine 16 disposed downstream of fan section 14. Although described below with reference to turbofan engine 10, the present application is generally applicable to turbomachinery, including turbojet engines, turboprop engines, and turboshaft gas turbine engines, including industrial and marine gas turbine engines and auxiliary power units. It may also be suitable for other high temperature applications containing water vapor in the gas phase, such as those resulting from the combustion of hydrocarbon fuels.

The exemplary core turbine engine 16 shown generally includes a generally tubular outer casing 18 defining an annular inlet 20. The housing 18 encloses, in serial flow relationship, a compressor section including a booster or Low Pressure (LP) compressor 22 and a High Pressure (HP) compressor 24; a combustion section 26; a turbine section including a High Pressure (HP) turbine 28 and a Low Pressure (LP) turbine 30; and an injection exhaust nozzle section 32. A High Pressure (HP) shaft or spool (spool) 34 drivingly connects HP turbine 28 to HP compressor 24. A Low Pressure (LP) shaft or spool 36 drivingly connects LP turbine 30 to LP compressor 22.

For the illustrated embodiment, the fan section 14 includes a variable pitch fan 38, the variable pitch fan 38 having a plurality of fan blades 40 connected to a disk 42 in a spaced apart manner. As shown, the fan blades 40 extend generally outwardly from the disk 42 in a radial direction R. Since the fan blades 40 are operatively connected to a suitable actuating member 44 (the actuating member 44 is configured to collectively and consistently vary the pitch (pitch) of the fan blades 40), each fan blade 40 is rotatable relative to the disk 42 about a pitch axis P (a pitch axis). The fan blades 40, disk 42, and actuating member 44 are rotatable together about the longitudinal axis 12 by the LP spool 36 on an optional power gearbox 46. The power gearbox 46 includes a plurality of gears for reducing the rotational speed of the LP spool 36 to a more efficient rotational fan speed.

Still referring to the exemplary embodiment of FIG. 2, the disk 42 is covered by a rotatable forward nacelle 48, the forward nacelle 48 having an aerodynamic profile to facilitate airflow through the plurality of fan blades 40. Further, the exemplary fan section 14 includes an annular fan casing or nacelle 50 that circumferentially surrounds at least a portion of the fan 38 and/or the core turbine engine 16. It should be appreciated that the nacelle 50 may be configured to be supported relative to the core turbine engine 16 by a plurality of circumferentially spaced outlet guide vanes 52. Further, the downstream section 54 of the nacelle 50 may extend beyond the exterior of the core turbine engine 16 to define a bypass airflow passage 56 therebetween.

During operation of turbofan engine 10, a volume of air 58 enters turbofan engine 10 through nacelle 50 and/or an associated inlet 60 of fan section 14. As a volume of air 58 passes over the fan blades 40, a first portion 62 of the air 58 is directed or channeled into the bypass airflow passage 56 as indicated by the arrows, and a second portion 64 of the air 58 is directed or channeled into the LP compressor 22 as indicated by the arrows. The ratio between the first portion of air 62 and the second portion of air 64 is commonly referred to as the bypass ratio. The pressure of the second portion 64 of air then increases as it is passed through the High Pressure (HP) compressor 24 and into the combustion section 26, where the second portion 64 of air mixes with fuel and combusts to provide combustion gases 66.

The combustion gases 66 are channeled through HP turbine 28 wherein heat energy and/or a portion of the kinetic energy from combustion gases 66 are extracted via stages of sequential HP turbine stator vanes 68 (connected to casing 18) and HP turbine rotor blades 70 (connected to HP shaft or spool 34) thereby causing HP shaft or spool 34 to rotate, thereby supporting operation of HP compressor 24. The combustion gases 66 are then channeled through LP turbine 30 wherein thermal energy and a second portion of the kinetic energy are extracted from combustion gases 66 via stages of sequential LP turbine stator vanes 72 (coupled to casing 18) and LP turbine rotor blades 74 (coupled to LP shaft or spool 36), thereby causing LP shaft or spool 36 to rotate, thereby supporting operation of LP compressor 22 and/or rotation of fan 38.

The combustion gases 66 are then channeled through injection exhaust nozzle section 32 of core turbine engine 16 to provide propulsion thrust. At the same time, as the first portion of air 62 is channeled through bypass airflow passage 56 (also providing propulsive thrust) before it is discharged from fan nozzle exhaust section 76 of turbofan engine 10, the pressure of first portion of air 62 increases substantially. The HP turbine 28, the LP turbine 30, and the injection exhaust nozzle section 32 at least partially define a hot gas path 78 for channeling the combustion gases 66 through the core turbine engine 16.

Other aspects of the application are provided by the subject matter of the following clauses:

1. a composition comprising: a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, wherein the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _a Ln ² _a Ln ³ _a Ln ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇ ，

wherein Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ And Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; a is 0.2 or 0.25; b is 0.2 when a is 0.2, and b is 0 when a is 0.25; m is Zr, hf or a mixture thereof.

2. The composition of any of the preceding clauses wherein a is 0.2 such that the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _0.2 Ln ² _0.2 Ln ³ _0.2 Ln ⁴ _0.2 Ln ⁵ _0.2 ) ₂ M ₂ O ₇ ，

wherein Ln ¹ 、Ln ² 、Ln ³ 、Ln ⁴ And Ln ⁵ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; m is Zr, hf or a mixture thereof.

3. The composition of any of the preceding clauses wherein Ln ⁵ And M has a second atomic radius ratio of 1.35 to 1.45 or 1.46 to 1.78.

4. The composition of any of the preceding clauses wherein a is 0.25 and b is 0 such that the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _0.25 Ln ² _0.25 Ln ³ _0.25 Ln ⁴ _0.25 ) ₂ M ₂ O ₇ ，

wherein Ln ¹ 、Ln ² 、Ln ³ And Ln ⁴ Each of which is a different rare earth element such that Ln ¹ And M has a first atomic radius ratio, ln, of from 1.35 to 1.45 ² And M has a second atomic radius ratio of 1.35 to 1.45, ln ³ And M has a third atomic radius ratio, ln, of from 1.46 to 1.78 ⁴ And M has a fourth atomic radius ratio of 1.46 to 1.78; m is Zr, hf or a mixture thereof.

5. The composition of any of the preceding clauses wherein M is 50 atomic% to 100 atomic% Zr.

6. The composition of any of the preceding clauses wherein M is 95 atomic% to 100 atomic% Zr.

7. The composition of any of the preceding clauses wherein M consists of Zr.

8. The composition of any of the preceding clauses wherein Ln ¹ And Ln ² Each of which is not selected from Tb, dy, Y, ho, er, tm, yb and LuThe same rare earth element.

9. The composition of any of the preceding clauses wherein Ln ³ And Ln ⁴ Each of which is a different rare earth element selected from La, ce, pr, nd, pm, sm, eu and Gd.

10. The composition of any of the preceding clauses wherein the composition has a thermal conductivity of 0.5W/m-K to 1.5W/m-K at 1000 ℃ in a 95-100% dense disk as measured by laser flash method according to ASTM E1461-13.

11. The composition of any of the preceding clauses, wherein the composition is selected from the group consisting of:

(Nd _0.2 Eu _0.2 Y _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Tb _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Gd _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Y _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 La _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Y _0.2 Dy _0.2 Er _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Er _0.2 ) ₂ Zr ₂ O ₇ ；

(Sm _0.2 Eu _0.2 Ho _0.2 Dy _0.2 Lu _0.2 ) ₂ Zr ₂ O ₇ ；

(Nd _0.25 Eu _0.25 Ho _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ ；

(Nd _0.25 Eu _0.25 Y _0.25 Dy _0.25 ) ₂ Zr ₂ O ₇ ；

12. A coated component comprising: a substrate having a surface; a thermal barrier coating on the surface, wherein the thermal barrier coating comprises a layer comprising the composition of any of the preceding clauses.

13. A coated component comprising: a substrate having a surface; a thermal barrier coating on the surface, wherein,

the thermal barrier coating comprises a layer comprising a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, wherein the layer has a thermal conductivity of 0.5W/m-K to 1.5W/m-K at 1000 ℃ in a 95-100% dense disk as measured by laser flash method according to ASTM E1461-13.

14. The coated member according to any one of the preceding clauses wherein,

the layer has an indentation fracture toughness in a 95-100% dense disk of 2MPa-m ^0.5 ～3MPa-m ^0.5 。

15. The coated member according to any one of the preceding clauses wherein,

the rare earth doped zirconium/hafnium oxide contains 4 or 5 different rare earth elements each present in substantially equal atomic percentages.

16. The coated member according to any one of the preceding clauses wherein,

the layer comprises a single phase defect-fluorite structured rare earth doped zirconium/hafnium oxide.

17. The coated member according to any one of the preceding clauses wherein,

the layer comprises a rare earth doped zirconium/hafnium oxide of a single phase pyrochlore structure.

18. The coated member according to any one of the preceding clauses wherein,

rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or pyrochlore structure has the formula:

(Ln ¹ _a Ln ² _a Ln ³ _a Ln ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇ ，

19. The coated member according to any one of the preceding clauses wherein M is 95 to 100 atomic% Zr.

20. A method of forming a rare earth doped zirconium/hafnium oxide, the method comprising:

combining 4 or 5 different rare earth zirconium/hafnium oxides to form a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or pyrochlore structure, wherein a first rare earth oxide comprises a first rare earth element having a first atomic radius ratio to Zr of 1.35-1.45, a second rare earth oxide comprises a second rare earth element having a second atomic radius ratio to Zr of 1.35-1.45, a third rare earth oxide comprises a third rare earth element having a third atomic radius ratio to Zr of 1.46-1.78, and a fourth rare earth oxide comprising a fourth rare earth element having a fourth atomic radius ratio to Zr of 1.46-1.78, wherein each of the different rare earth zirconium/hafnium oxides is present at substantially equal atomic weights of their respective rare earth elements.

This written description uses example embodiments to disclose the application, including the best mode, and also to enable any person skilled in the art to practice the application (including making and using any devices or systems and performing any incorporated methods). The patentable scope of the application is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A composition comprising:

a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, wherein the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _a Ln ² _a Ln ³ aLn ⁴ _a Ln ⁵ _b ) ₂ M ₂ O ₇ ，

in the method, in the process of the application,

a is 0.2 or 0.25;

b is 0.2 when a is 0.2, and b is 0 when a is 0.25; and

m is Zr, hf or a mixture thereof.

2. The composition of claim 1, wherein a is 0.2 such that the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _0.2 Ln ² _0.2 Ln ³ _0.2 Ln ⁴ _0.2 Ln ⁵ _0.2 ) ₂ M ₂ O ₇ ，

in the method, in the process of the application,

m is Zr, hf or a mixture thereof.

3. The composition of claim 2, wherein Ln ⁵ And M has a second atomic radius ratio of 1.35 to 1.45 or 1.46 to 1.78.

4. The composition of claim 1, wherein a is 0.25 and b is 0 such that the rare earth doped zirconium/hafnium oxide has the formula:

(Ln ¹ _0.25 Ln ² _0.25 Ln ³ _0.25 Ln ⁴ _0.25 ) ₂ M ₂ O ₇ ，

in the method, in the process of the application,

m is Zr, hf or a mixture thereof.

5. The composition of claim 1, wherein M is 50 atomic% to 100 atomic% Zr.

6. The composition of claim 1, wherein M is 95 atomic% to 100 atomic% Zr.

7. The composition of claim 1, wherein M consists of Zr.

8. A coated member, wherein the coated member comprises:

a substrate having a surface; and

a thermal barrier coating on the surface, the thermal barrier coating comprising a layer comprising the composition of claim 1.

9. A coated member, wherein the coated member comprises:

a substrate having a surface; and

a thermal barrier coating on the surface, the thermal barrier coating comprising a layer comprising a rare earth doped zirconium/hafnium oxide having a defect-fluorite structure or a pyrochlore structure, the layer having a thermal conductivity of 0.5W/m-K to 1.5W/m-K at 1000 ℃ in a 95-100% dense disk as measured by laser flash method according to ASTM E1461-13.

10. A method of forming a rare earth doped zirconium/hafnium oxide, the method comprising: