THERMALLY STABLE THERMAL BARRIER COATINGS THAT EXHIBIT IMPROVED THERMAL CONDUCTIVITY AND EROSION RESISTANCE

Abstract

A thermal spray material that exhibits improved thermal conductivity and solid particle erosion resistance is provided for thermal barrier coatings. The thermal spray material forms a thermally stable coating when thermally sprayed. The coating includes at least one phase that exhibits improved thermal conductivity and at least one phase that exhibits improved solid particle erosion resistance.

Claims

1. A thermal spray material for thermal barrier coatings, comprising: component (A) having erosion resistance; and component (B) having thermal conductivity.

2. The thermal spray material according to claim 1, wherein the component (A) comprises a partially stabilized zirconium oxide.

3. The thermal spray material according to claim 2, wherein the partially stabilized zirconium oxide comprises a primary stabilizer in an amount of 0.1-7 mol %, and wherein the primary stabilizer is an ytterbium oxide and/or a dysprosium oxide.

4. The thermal spray material according to claim 3, wherein the partially stabilized zirconium oxide comprises a primary stabilizer in an amount of 4-7 mol %, and wherein the primary stabilizer is an ytterbium oxide and/or a dysprosium oxide.

5. The thermal spray material according to claim 3, wherein the partially or the fully stabilized zirconia comprises a stabilizer oxide, and wherein the stabilizer oxide comprises 4-7 mol % ytterbium oxide.

6. The thermal spray material according to claim 1, wherein the component (B) comprises a partially or a fully stabilized zirconia.

7. The thermal spray material according to claim 6, wherein the partially or the fully stabilized zirconia comprises a stabilizer oxide in an amount of 3-35 mol %, and wherein the stabilizer oxide is selected from the group consisting of yttrium oxide, gadolinium oxide, dysprosium oxide, and ytterbium oxide.

8. The thermal spray material according to claim 6, wherein the partially or the fully stabilized zirconia comprises a stabilizer oxide, and wherein the stabilizer oxide comprises 5-6 mol % yttrium oxide and 1-3 mol % gadolinium oxide.

9. The thermal spray material according to claim 6, wherein the partially or the fully stabilized zirconia comprises a stabilizer oxide, and wherein the stabilizer oxide comprises 2-5 mol % dysprosium oxide.

10. A method for manufacturing a thermally stable multiphase coating material for thermal barrier coatings comprising: blending component (A) having erosion resistance with component (B) having thermal conductivity to obtain a thermal spray material; and plasma spraying the thermal spray material to obtain the thermally stable multiphase coating material comprising at least one erosion resistant phase and at least one thermal conductivity phase.

11. The method according to claim 10, wherein the component (A) and the component (B) are not alloyed together prior to plasma spraying.

12. A thermally stable multiphase coating material obtained from the thermal spray material according to claim 1, comprising: at least one erosion resistance phase; and at least one thermal conductivity phase.

13. The thermal stable multiphase coating material according to claim 12, wherein the at least one erosion resistance phase is in a range of 50-90 wt % of the thermal stable multiphase coating material and the at least one thermal conductivity phase is in a range of 10-50 wt % of the thermal stable multiphase coating material.

14. The thermal stable multiphase coating material according to claim 13, wherein the at least one erosion resistance phase is in a range of 60-80 wt % of the thermal stable multiphase coating material and the at least one thermal conductivity phase is in a range of 20-40 wt % of the thermal stable multiphase coating material.

15. The thermal stable multiphase coating material according to claim 13, wherein the at least one erosion resistance phase is in a range of 65-75 wt % of the thermal stable multiphase coating material and the at least one thermal conductivity phase is in a range of 25-35 wt % of the thermal stable multiphase coating material.

16. The thermal stable multiphase coating material according to claim 12, wherein the at least one erosion resistance phase comprises an ytterbium-oxide stabilized zirconium oxide comprising 84-86 wt % ZrO.sub.2 and 14-16 wt % Yb.sub.2O.sub.3, and wherein the at least one thermal conductivity phase comprises a cubic-zirconium oxide comprising 78-81 wt % ZrO.sub.2, 9-10 wt % Y.sub.2O.sub.3, 5-6 wt % Gd.sub.2O.sub.3, and 5-6 wt % Yb.sub.2O.sub.3.

17. The thermal stable multiphase coating material according to claim 12, wherein the at least one erosion resistance phase comprises an ytterbium-oxide stabilized zirconium oxide comprising 82-86 wt % ZrO.sub.2 and 14-18 wt % Yb.sub.2O.sub.3, and wherein the at least one thermal conductivity phase comprises a dysprosium-oxide stabilized zirconium oxide comprising 88-92 wt % ZrO.sub.2 and 9-11 wt % Dy.sub.2O.sub.3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present disclosure is further described in the detailed description which follows, in reference to the noted plurality of drawings, by way of non-limiting examples of preferred embodiments of the present disclosure.

[0019] FIG. 1 illustrates a multiphase coating layer applied onto a substrate, according to various embodiments.

[0020] FIG. 2A is a scanning electron microscope (SEM) image showing a thermal spray material, according to an embodiment of the present disclosure.

[0021] FIG. 2B is a SEM image showing a thermally sprayed coating applied by atmospheric plasma spraying (APS), according to an embodiment of the present disclosure.

[0022] FIG. 3A is a SEM image showing a thermal spray material, according to an embodiment of the present disclosure.

[0023] FIG. 3B is a SEM image showing a lower conductivity phase of a thermally sprayed coating applied by APS, according to an embodiment of the present disclosure.

[0024] FIG. 3C is a SEM image showing an erosion resistant phase of a thermally sprayed coating applied by APS, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0025] In FIG. 1, the multiphase coating layer 15 includes at least one erosion resistant phase 110 and at least one thermal conductivity phase 120. The term phase refers to attributes of each component in the thermal spray material prior to plasma spraying the thermal spray material to obtain the multiphase coating layer 15. The multiphase coating layer 15 is applied onto a substrate layer 10 (e.g., metal or ceramic).

[0026] In one embodiment, the erosion resistant phase 110 includes a partially stabilized zirconium oxide that includes primary stabilizers, such as ytterbium oxide and/or dysprosium oxide in an amount ranging from 0.1-6.0 mol %.

[0027] In one embodiment, the low thermal conductivity phase 120 includes a partially or a fully stabilized zirconia (or zirconates) that includes stabilizer oxides, including yttrium, gadolinium, dysprosium, and/or ytterbium. In embodiments, the total amount of the stabilizer oxides in the thermal conductivity phase is in a range of 3-35 mol %.

[0028] A thermal spray material can be manufactured by blending or cladding the at least one erosion resistant phase 110 and the at least one thermal conductivity phase 120. A multiphase coating layer 15 is formed by plasma spraying the thermal spray material onto a substrate 10.

EXAMPLES

Example 1

[0029] A thermal spray material according to a preferred embodiment of the present disclosure was produced by blending component (A) 210 having erosion resistance and component (B) 200 having thermal conductivity. The resulting microstructure of the thermal spray material is shown in FIG. 2A. The chemical composition of component (A) 210 was as follows: 93-96 mol % ZrO.sub.2 and 4-7 mol % Yb.sub.2O.sub.3 (or 82-86 wt % ZrO.sub.2 and 14-18 wt % Yb.sub.2O.sub.3). The chemical composition of component (B) 200 was as follows: 88-93 mol % ZrO.sub.2, 1-3 mol % Yb.sub.2O.sub.3, 5-6 mol % Y.sub.2O.sub.3, and 1-3 mol % Gd.sub.2O.sub.3 (or 78-81 wt % ZrO.sub.2, 5-6 wt % Yb.sub.2O.sub.3, 9-10 wt % Y.sub.2O.sub.3, and 5-6 wt % Gd.sub.2O.sub.3).

[0030] Then, the thermal spray material was thermally sprayed by Atmospheric Plasma Spraying (APS) to obtain the thermally stable multiphase coating material. The resulting microstructure of the thermally stable multiphase coating material is shown in FIG. 2B.

[0031] FIG. 2B shows a SEM image of a thermally stable multiphase coating material that includes at least two phases: (1) a thermal conductivity phase 230, and (2) an erosion resistant phase 220. The thermal conductivity phase 230 constituted 30 wt % of the total thermally stable multiphase coating material. The chemical composition of the thermal conductivity phase 230 was a cubic-zirconium oxide that included 78-81 wt % ZrO.sub.2, 9-10 wt % Y.sub.2O.sub.3, 5-6 wt % Gd.sub.2O.sub.3, and 5-6 wt % Yb.sub.2O.sub.3.

[0032] The erosion resistant phase 220 was 70 wt % of the total thermal stable multiphase coating material. The chemical composition of the erosion resistant phase 220 constituted an ytterbium-oxide stabilized zirconium oxide that included 84-86 wt % ZrO.sub.2 and 14-16 wt % Yb.sub.2O.sub.3.

[0033] The chemical composition of the combination of both the thermal conductivity phase 230 and the erosion resistant phase 220 was as follows: 91-94.5 mol % ZrO.sub.2, 4-5 mol % Yb.sub.2O.sub.3, 1-3 mol % Y.sub.2O.sub.3, and 0.5-1.0 mol % Gd.sub.2O.sub.3 (or 81-83 wt % ZrO.sub.2, 12-14 wt % Yb.sub.2O.sub.3, 2-4 wt % Y.sub.2O.sub.3, and 2-4 wt % Gd.sub.2O.sub.3).

[0034] The thermal conductivity of individual and combined phases were determined by comparing coatings with comparable porosity. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Normalized Thermal Coating Conductivity at 25 C. Component A 1.0 Component B 0.8 70% Component A and 0.75 30% Component B

[0035] The erosion resistance of individual and combined phases were determined by comparing coatings with comparable porosity. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Normalized Solid Erosion Coating Resistance Component A 1.0 Component B 0.25 70% Component A and 0.45 30% Component B

Example 2

[0036] A thermal spray material according to another preferred embodiment of the present disclosure was produced by blending component (A) 300 having erosion resistance and component (B) 310 having thermal conductivity. The resulting microstructure of the thermal spray material is shown in FIG. 3A. The chemical composition of component (A) 300 was as follows: 93-96 mol % ZrO.sub.2 and 4-7 mol % Yb.sub.2O.sub.3 (or 82-86 wt % ZrO.sub.2 and 14-18 wt % Yb.sub.2O.sub.3). The chemical composition of component (B) 310 was as follows: 95-98 mol % ZrO.sub.2 and 2-5 mol % Dy.sub.2O.sub.3 (or 88-92 wt % ZrO.sub.2 and 8-12 wt % Dy.sub.2O.sub.3).

[0037] Then, the thermal spray material was thermally sprayed by APS to obtain the thermally stable multiphase coating material. The resulting microstructure of the thermal conductivity phase in the thermally stable multiphase coating material is shown in FIG. 3B. The resulting microstructure of the erosion resistance layer in the thermally stable multiphase coating material is shown in FIG. 3C.

[0038] FIG. 3B shows a SEM image of a thermal conductivity phase in the thermally stable multiphase coating material that included 88-92 wt % ZrO.sub.2 and 9-11 wt % Dy.sub.2O.sub.3. The thermal conductivity phase was 30 wt % of the total thermal stable multiphase coating material. The chemical composition of the thermal conductivity phase in the thermal stable multiphase coating material was a dysprosium-oxide stabilized zirconium oxide that included 88-92 wt % ZrO.sub.2 and 9-11 wt % Dy.sub.2O.sub.3.

[0039] FIG. 3C shows a SEM image of an erosion resistance phase in the thermally stable multiphase coating material. The erosion resistant phase was 70 wt % of the total thermal stable multiphase coating material. The chemical composition of the erosion resistant phase in the thermal stable multiphase coating material was an ytterbium-oxide stabilized zirconium oxide that included 82-86 wt % ZrO.sub.2 and 14-18 wt % Yb.sub.2O.sub.3.

[0040] The chemical composition of the combination of both the thermal conductivity phase and the erosion resistant phase was as follows: 91-98 mol % ZrO.sub.2, 2-6 mol % Yb.sub.203, and 0.3-3 mol % DyO.sub.3 (or 80-92 wt % ZrO.sub.2, 7-14 wt % Yb.sub.2O.sub.3, and 1-6 wt % Dy.sub.2O.sub.3).

[0041] The thermal conductivity of individual and combined phases were determined by comparing coatings with comparable porosity. The results are shown in Table 3.

TABLE-US-00003 TABLE 3 Normalized Thermal Coating Conductivity at 25 C. Component A 1.0 Component B 0.95 70% Component A and 0.80 30% Component B

[0042] The erosion resistance of individual and combined phases were determined by comparing coatings with comparable porosity. The results are shown in Table 4.

TABLE-US-00004 TABLE 4 Normalized Solid Erosion Coating Resistance Component A 1.0 Component B 0.90 70% Component A and 0.95 30% Component B

[0043] Further, at least because the invention is disclosed herein in a manner that enables one to make and use it, by virtue of the disclosure of particular exemplary embodiments, such as for simplicity or efficiency, for example, the invention can be practiced in the absence of any additional element or additional structure that is not specifically disclosed herein.

[0044] It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.