Thermal barrier coating material method of production thereof, gas turbine member using the thermal barrier coating material, and gas turbine

• US 20040156724A1
• Filed: 12/08/2003
• Published: 08/12/2004
• Est. Priority Date: 06/15/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Aoki, Sunao, Takahashi, Kouji, Okada, Ikuo, Mori, Kazutaka, Torigoe, Taiji, Hirata, Takehiko, Kaneko, Hideaki, Ohara, Minoru
• Granted Patent: US 7,655,326 B2
• Time in Patent Office: Days
• US Class Current: 416/241R
• CPC Class Codes: C23C 28/3215 at least one MCrAlX layer
• CPC Class Codes: C23C 28/3455 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 Class Codes: C23C 4/073 containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements
• CPC Class Codes: C23C 4/11 Oxides
• CPC Class Codes: C23C 4/18 After-treatment
• CPC Class Codes: F01D 5/288 Protective coatings for blades
• CPC Class Codes: F05D 2230/31 Layer deposition
• CPC Class Codes: F05D 2230/311 by torch or flame spraying
• CPC Class Codes: F05D 2230/312 by plasma spraying
• CPC Class Codes: F05D 2230/40 Heat treatment
• CPC Class Codes: F05D 2230/90 Coating; Surface treatment
• CPC Class Codes: F05D 2300/2118 Zirconium oxides

Abstract

The invention relates to a thermal barrier coating material for coating a gas turbine member that provides a higher thermal barrier property and a higher peeling resistance. In a first aspect of the invention, a metal binding layer 22 and a porous ZrO₂-based ceramic layer 23 are laminated successively on a base material 21, and microcracks that extend in the thickness direction are formed in the ceramic layer 23. After laminating the ceramic layer 23 on the metal binding layer 22 by thermal spraying, etc., microcracks 24 are formed by irradiating with a laser beam a surface of the ceramic layer 23 and thereby heating the surface of the ceramic layer 23 at 1000° C. to 1700° C., while cooling the rear surface of the base material 21. Thus, microcracks 24 are formed by a heating and cooling cycle.

Claims

1. A thermal barrier coating material, comprising a metal binding layer laminated on a base material and a ceramic layer laminated on the metal binding layer, the ceramic layer comprising partially stabilized ZrO₂ which is porous and has microcracks that extend in a thickness direction of the ceramic layer.

2. The thermal barrier coating material according to claim 1, wherein a porosity of a porous portion of said ceramic layer is in a range of 1% to 30%.

3. The thermal barrier coating material according to claim 1 or 2, wherein a density of a porous portion of said ceramic layer is in a range of 4 g/mm³ to 6.5 g/mm³.

4. The thermal barrier coating material according to any one of claims 1 to 3, wherein a thermal conductivity of said ceramic layer is in a range of 0.5 w/m·

K to 5 w/m·

K.

5. The thermal barrier coating material according to claim 1, wherein the number of said microcracks per unit length (1 mm) on a section of said ceramic layer is in a range of 1 to 10.

18. A gas turbine member, comprising the thermal barrier coating material according to any one of claims 1 to 5 and claims 14 to 17.

19. A gas turbine, comprising the gas turbine member according to claim 18.

6. A method for producing a thermal barrier coating material comprising the steps of:

laminating a metal binding layer on a surface of a base material;

laminating a ceramic layer on a surface of the metal binding layer; and

forming microcracks that extend in a thickness direction in said ceramic layer by irradiating a surface of said ceramic layer with a laser beam and thereby heating the surface of said ceramic layer while cooling a rear surface of said base material.

7. The method for producing a thermal barrier coating material according to claim 6, wherein said surface of said ceramic layer is irradiated with said laser beam at a diameter range of 10 to 40 mm.

8. The method for producing a thermal barrier coating material according to claim 6 or 7, wherein the surface of said ceramic layer is heated to a temperature in a range of 1000 to 1700°

C. by irradiation of said laser beam.

9. The method for producing a thermal barrier coating material according to any one of claims 6 to 8, wherein said irradiation with said laser beam is carried out from 5 to 1000 times with a proviso that neither phase modification nor sintering of partially stabilized ZrO₂ occurs.

10. The method for producing a thermal barrier coating material according to any one of claims 6 to 9, wherein said ceramic layer has a porosity in a range of 1 to 30%.

11. The method for producing a thermal barrier coating material according to any one of claims 6 to 10, wherein said ceramic layer has a density in a range of 4 g/mm³ to 6.5 g/mm³.

12. The method for producing a thermal barrier coating material according to any one of claims 6 to 11, wherein said microcracks are formed so that thermal conductivity is in a range of 0.5 w/m·

K to 5 w/m·

K.

13. The method for producing a thermal barrier coating material according to any one of claims 6 to 12, wherein said microcracks are formed so that the number of said microcracks per unit length (1 mm) of a section of said ceramic layer is in a range of 1 to 10.

14. A thermal barrier coating material, comprising a metal binding layer laminated on a base material and a ceramic layer laminated on the metal binding layer, the ceramic layer comprising partially stabilized ZrO₂ which is partially stabilized by additives of Dy₂O₃ and Yb₂O₃.

15. The thermal barrier coating material according to claim 14, wherein said Dy₂O₃ is in a range of 0.01 wt % to 16.00 wt %, said Yb₂O₃ is in a range of 0.01 wt % to 17.00 wt %, a sum of said Dy₂O₃ and said Yb₂O₃ is in a range of 10 wt % to 20 wt %, and said ZrO₂ excluding stabilizers is in a range of 80 wt % to 90 wt %.

16. The thermal barrier coating material according to claim 14 or 15, wherein said ceramic layer is a film produced by thermal spraying of a ZrO₂—

Dy₂O₃—

Yb₂O₃ powder which has been obtained from a solid solution of a mixture of ZrO₂, Dy₂O₃ and Yb₂O₃ powders.

17. The thermal barrier coating material according to any one of claims 14 to 16, wherein said ceramic layer is a film formed by an electron beam physical vapor deposition of an ingot having a predetermined composition.

20. A TBC raw material for thermal spraying, comprising a zirconia powder having a specific surface area of at least 10 m²/g and a rare earth oxide powder having a specific surface area of at least 10 m²/g.

22. A gas turbine member comprising a film produced by thermal spraying of the TBC raw material according to claim 20.

21. A method for producing a TBC raw material for thermal spraying, comprising steps of mixing a zirconia powder having a specific surface area of at least 10 m²/g and a rare earth oxide powder having a specific surface area of at least 10 m²/g along with a binder or dispersant so as to form a slurry, then granulating to form particles having a mean particle diameter of 10 to 100 μ

m, and then heating at 1300 to 1600°

C. for 1 to 10 hours.

23. A gas turbine comprising the gas turbine member according to claim 21.