METHOD AND DEVICE FOR ESTIMATING A THICKNESS OF A CERAMIC THERMAL BARRIER COATING

• US 20150310133A1
• Filed: 12/21/2012
• Published: 10/29/2015
• Est. Priority Date: 12/23/2011
• Status: Active Grant

• Current Assignee: Safran Aircraft Engine Company
• Original Assignee: Snecma (Safran SA)
• Inventors: BOHEAS, Marie-Ange, HAMADI, Sarah, MALIE, Andr, PASQUET, Annie
• Granted Patent: US 10,445,434 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 17/10 Complex mathematical operations function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: G06F 30/23 using finite element methods [FEM] or finite difference methods [FDM]

Abstract

An estimation method for estimating thickness of a ceramic thermal barrier coating that is to be deposited by physical vapor deposition from at least one target and onto a gas turbine hot part mounted on a support tooling, the method including: digitally modeling a geometrical shape of the hot part and its movements relative to the target; representing the modeled hot part as a surface mesh; and estimating, for at least one mesh element of the hot part exposed to the radiation from the target during deposition of the coating, a coating thickness to be deposited on the mesh element at a given instant by using a radiation model modeling radiation from the target and taking account of the position of the mesh element at that given instant relative to the target.

Claims

1-12. -12. (canceled)

13. An estimation method for estimating thickness of a ceramic thermal barrier coating that is to be deposited by physical vapor deposition from at least one target and onto a gas turbine hot part mounted on support tooling, the method comprising:

digitally modeling a geometrical shape of the hot part and its movements relative to the at least one target;

representing the hot part as digitally modeled as a surface mesh;

digitally modeling the geometrical shape of the at least one target;

representing the at least one target as digitally modeled as a surface mesh; and

estimating, for at least one mesh element of the hot part exposed to radiation from the at least one target during deposition of the coating, a coating thickness to be deposited on the mesh element at a given instant by using a radiation model modeling radiation from the at least one target and taking account of a position of the mesh element at that given instant relative to the at least one target, the radiation model being defined for a mesh element of the at least one target by;

I(θ

)=I₀[cos(θ

)]ⁿ

wherein;

I(θ

) designates intensity of a ray emitted by the mesh element of the at least one target in a direction at an angle θ

relative to the normal to the mesh element; and

n and I₀ designate predetermined constants.

14. A method according to claim 13, further comprising:

digitally modeling at least one mask configured to prevent a zone of the hot part being exposed to the radiation from the at least one target; and

representing the at least one mask as a surface mesh; and

wherein the mesh elements of the hot part that are taken into consideration during the estimating comprise mesh elements that are not masked at the given instant from the at least one target by mesh elements of the at least one mask during deposition of the coating.

15. A method according to claim 14, wherein the at least one mask comes from an element of the support tooling for supporting the hot part.

16. A method according to claim 15, further comprising:

digitally modeling the support tooling for supporting the hot part; and

representing the support tooling as digitally modeled as a surface mesh.

17. An estimation method according to claim 13, wherein during the estimating, account is also taken of a loss factor corresponding to rays that are emitted by the at least one target during deposition but that do not reach the hot part.

18. A method according to claim 16, wherein fineness of the surface mesh varies between the hot part, the target, the mask, and/or the support tooling.

19. A method according to claim 13, wherein during the surface meshing the modeled hot part, the part is subjected to nonuniform surface meshing.

20. A non-transitory computer-readable data medium storing a computer program including instructions for executing the estimation method according to claim 13.

21. The use of the method according to claim 13, for estimating a thickness of a ceramic thermal barrier coating that is to be deposited by physical vapor deposition from at least one target on a rotor blade of a gas turbine.

22. The use of the method according to claim 13, for estimating a thickness of a ceramic thermal barrier coating that is to be deposited by physical vapor deposition from at least one target on a stator blade of a gas turbine.

23. A device for estimating thickness of a ceramic thermal barrier coating that is to be deposited by physical vapor deposition from at least one target and onto a gas turbine hot part mounted on support tooling, the device comprising:

means for digitally modeling a geometrical shape of the hot part and its movements relative to the at least one target;

means for representing the hot part as digitally modeled as a surface mesh;

means for digitally modeling the geometrical shape of the at least one target;

means for representing the at least one target as digitally modeled as a surface mesh; and

means for estimating, for at least one mesh element of the hot part exposed to the radiation from the at least one target during deposition of the coating, a coating thickness to be deposited on the mesh element at a given instant by using a radiation model modeling radiation from the at least one target and taking account of a position of the mesh element at that given instant relative to the at least one target, the radiation model being defined for a mesh element of the at least one target by;

I(θ

)=I₀[cos(θ

)]ⁿ

wherein;

I(θ

) designates intensity of a ray emitted by the mesh element of the at least one target in a direction at an angle θ

relative to the normal to the mesh element; and

n and I₀ designate predetermined constants.