Thermal barrier coating, turbine member, and gas turbine

Patent metadata

Field	Value
Publication number	US-10808308-B2
Application number	US-201716306635-A
Country	US
Kind code	B2
Filing date	Jun 6, 2017
Priority date	Jun 8, 2016
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A thermal barrier coating includes a highly porous layer and a dense layer. The highly porous layer is formed on a heat-resistant base, is made of ceramic, has pores, has a layer thickness of equal to or larger than 0.3 mm and equal to or smaller than 1.0 mm, and has a pore ratio of equal to or higher than 1 vol % and equal to or lower than 30 vol %. The dense layer is formed on the highly porous layer, is made of ceramic, has a pore ratio of equal to or lower than 0.9 vol % that is equal to or lower than the pore ratio of the highly porous layer, and has a layer thickness of equal to or smaller than 0.05 mm.

First claim

The invention claimed is:

1. A thermal barrier coating comprising:
a highly porous layer formed on a heat-resistant base, the highly porous layer being made of ceramic; and having pores, the highly porous layer having a layer thickness of equal to or larger than 0.3 mm and equal to or smaller than 1.0 mm, and having a pore ratio of equal to or higher than 1 vol % and equal to or lower than 30 vol %, the highly porous layer being made of an ytterbia-stabilized zirconia material;
a dense layer formed on the highly porous layer, the dense layer having a pore ratio of equal to or lower than 0.9 vol % that is lower than the pore ratio of the highly porous layer, and the dense layer having a layer thickness of equal to or smaller than 0.05 mm and being made of an ytterbia-stabilized zirconia material or an yttria-stabilized zirconia material; and
a molten layer formed on the dense layer by melting a portion of the dense layer;
wherein a thickness of the dense layer remaining under the molten layer is equal to or larger than 0.01 mm, and the molten layer has a thickness of equal to or larger than the thickness of the dense layer and no greater than 0.04 mm.

2. The thermal barrier coating according to claim 1 , further comprising:
a metal bonding layer formed between the heat-resistant base and the highly porous layer.

3. The thermal barrier coating according to claim 2 , wherein the metal bonding layer is made of an MCrAlY alloy, wherein M is a metal comprising Ni, Co, Fe, or a combination thereof.

4. The thermal barrier coating according to claim 1 , wherein the dense layer is made of the ytterbia-stabilized zirconia material.

5. The thermal barrier coating according to claim 1 , wherein the dense layer has a Vickers hardness of equal to or higher than 800 Hv.

6. The thermal barrier coating according to claim 5 , wherein the highly porous layer has a Vickers hardness of equal to or higher than 800 Hv.

7. The thermal barrier coating according to claim 1 , wherein the highly porous layer has vertical cracks in a surface where the dense layer is provided.

8. The thermal barrier coating according to claim 7 , wherein the vertical cracks of the highly porous layer have one to ten vertical cracks per mm in a surface where the dense layer is provided.

9. The thermal barrier coating according to claim 1 , wherein the dense layer has a particle size distribution in which the average particle diameter of ceramic is equal to or smaller than 20 μm.

10. A turbine member comprising the thermal barrier coating according to claim 1 on a surface.

11. The turbine member of claim 7 , wherein the turbine member is a compressor blade or vane.

12. A gas turbine comprising the turbine member according to claim 10 .

13. A method of producing a thermal barrier coating comprising:
forming a highly porous layer on a heat-resistant base by atmospheric plasma spraying, the highly porous layer being made of ceramic and having pores, the highly porous layer having a layer thickness of equal to or larger than 0.3 mm and equal to or smaller than 1.0 mm, and having a pore ratio of equal to or higher than 1 vol % and equal to or lower than 30 vol %;
forming a dense layer on the highly porous layer by atmospheric plasma spraying, cold spraying method, or an aerosol deposition method, the dense layer being made of ceramic and having a pore ratio of equal to or lower than 0.9 vol % that is lower than the pore ratio of the highly porous layer, and the dense layer having a layer thickness of equal to or smaller than 0.05 mm;
melting a portion of the dense layer to form a molten layer on the dense layer;
wherein a thickness of the dense layer remaining under the molten layer is equal to or larger than 0.01 mm, and the molten layer has a thickness of equal to or larger than the thickness of the dense layer and no greater than 0.04 mm.

14. The method of producing a thermal barrier coating according to claim 13 , wherein the dense layer is formed on a surface of the highly porous layer by short-distance spraying of equal to or shorter than 100 mm by the atmospheric plasma spraying.

15. The method of producing a thermal barrier coating according to claim 13 , wherein melting the portion of the dense layer is performed by laser scanning the outer surface of the dense layer.

16. The method of producing a thermal barrier coating according to claim 13 , further comprising:
prior to forming the highly porous layer, forming a metal bonding layer on the heat resistant base by low pressure plasma spraying (LPPS), high velocity oxygen fuel (HVOF) spraying, or atmospheric plasma spraying (APS).

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Tanigawa Shuji
• Mega Masahiko
• Torigoe Taiji
• Okajima Yoshifumi
• Kudo Daisuke

Classifications

• C23C30/00

  Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process (C23C26/00, C23C28/00 take precedence) · CPC title

• C23C28/36

  including layers graded in composition or physical properties · CPC title

• C23C28/3455 Primary

  with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer · CPC title

• C23C28/345

  with at least one oxide layer · CPC title

• C23C28/3215

  at least one MCrAlX layer · CPC title