Thermal spray coating

Patent metadata

Field	Value
Publication number	US-2019177828-A1
Application number	US-201816217961-A
Country	US
Kind code	A1
Filing date	Dec 12, 2018
Priority date	Dec 13, 2017
Publication date	Jun 13, 2019
Grant date	—

Abstract

Example systems and techniques for controlling thermal spray processes and for determining properties of thermal spray coatings. A computing device may control a thermal spray gun to thermally spray a substrate in a thermal spray cycle including a plurality of passes of a coating material to form a coating. The computing device may determine a change in curvature of the substrate during the thermal spraying, and determine properties of the coating based on the changes in the curvature. The computing device may control the thermal spray gun based on the determined properties.

First claim

1 . A method comprising:
thermally spraying a substrate in a thermal spray cycle comprising a plurality of passes of a coating material to form a coating; determining, by a computing device, a change in curvature of the substrate Δκ during a central pass of the plurality of passes; and determining, by the computing device, residual stress σ of the coating based on the change in the curvature Δκ.

2 . The method of claim 1 , wherein determining the residual stress σ comprises determining, by the computing device, a change in a thickness Δt D of the coating during the central pass and determining the residual stress σ based on a relationship including Δt D and Δκ.

3 . The method of claim 2 , wherein determining the residual stress σ comprises evaluating, by the computing device, a thin film equation

σ
=

E
s
′



t
s
2


Δκ

6

Δ




t
D

,

where t s is a thickness of the substrate, wherein

E
s
′

=

E
s

1
-

v
s

,

wherein E s is the Young's modulus of the substrate, and wherein v s is the Poisson's ratio of the substrate.

4 . The method of claim 2 , wherein determining the residual stress σ comprises evaluating, by the computing device, a thick film equation

σ
=

E
s
′



t
s



(

t
s

+

β

5
/
4


Δ




t
D

)


Δκ

6

Δ




t
D

,

where t s is a thickness of the substrate, wherein

β
=

E
D
′

E
s
′

wherein

E
s
′

=

E
s

1
-

v
s

,

wherein E s is the Young's modulus of the substrate, wherein v s is the Poisson's ratio of the substrate, wherein

E
D
′

=

E
D

1
-

v
D

,

wherein E D is the Young's modulus of the coating, and wherein v D is the Poisson's ratio of the coating.

5 . The method of claim 1 , wherein determining the change in curvature of the substrate comprises determining a bending deflection of the substrate at at least one predetermined location along the substrate.

6 . The method of claim 5 , wherein the at least one predetermined location comprises at least three locations.

7 . The method of claim 5 , wherein determining the bending deflection comprises receiving, by the computing device, from a respective laser sensor adjacent each respective predetermined location of the at least one predetermined location or from a respective strain gauge in contact with the substrate at each respective predetermined location of the at least one predetermined location, a signal indicative of a respective deflection of the substrate at the respective predetermined location.

8 . The method of claim 1 , wherein the central pass is a respective pass of the plurality of passes that comprises the mid-point in time of the spraying cycle.

9 . The method of claim 1 , further comprising:
determining, by the computing device, a plurality of thermal spray parameters based on the residual stress σ, wherein the coating parameters are configured to produce a second coating with residual stress within a predetermined acceptable range; and thermally spraying a component with a plurality of passes based on the plurality of thermal spray parameters to produce the second coating.

10 . A system comprising:
a therm

Assignees

• Rolls Royce Corp
• Rolls Royce Plc

Inventors

• Shi Jun
• Mcintyre Roy Peter
• Sun Edward

Classifications

• G01B7/18

  using change in resistance · CPC title

• C23C4/134 Primary

  Plasma spraying · CPC title

• G01L5/00

  Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes · CPC title

• G01B11/16

  for measuring the deformation in a solid, e.g. optical strain gauge · CPC title

• C23C4/123

  Spraying molten metal · CPC title