Method for characterizing a paint compaction on a part

Abstract

The invention relates to a method for characterizing a paint compaction on a part, in particular a turbomachine part for an aircraft, wherein the characterization method comprises the steps of: a) Applying (100) a paint layer onto the part; b) Positioning (200) an instrumented Almen strip in the vicinity of the part; c) Projecting (300) an impacting media onto the thus-painted part and the instrumented Almen strip in order to compact the paint layer applied onto the part; d) Measuring (400) an Almen intensity of the projection using the instrumented Almen strip; and, e) Characterizing (500) the paint layer thus compacted on the part.

Description

DESCRIPTION Title: Method for characterizing paint compaction on a part Technical field of 'invention' [G0G1JThe invention relates to the field of paint compaction on a part. In particular, the invention relates to a method for characterizing paint compaction on a part, notably a turbomachine part for an aircraft. Prior art

[0002] Currently, on high-strength martensitic steel parts (Rm > 1100 MPa), such as compressor and low-pressure turbine shafts, an aluminum pigment paint with an inorganic binder is applied to protect the substrate against atmospheric corrosion. This type of paint acts against corrosion in two ways: as a barrier against the environment and as a sacrificial anode. To achieve the sacrificial effect, a post-curing compaction process is necessary, achieved by projecting a media onto the painted surface. This process establishes electrical contact between the aluminum particles through plastic deformation under the impact of the projected media. This compaction process then allows the paint to act as a sacrificial anode, its purpose being to chemically degrade at the expense of the substrate.

[0003] During the projection of impacting media, to control surface compression, Aimen test specimens, known in themselves, are placed on the part(s). These Aimen specimens are made of XC65 or XC70 steel, with a hardness of 44 to 50 HRC. They measure 76.2 mm in length, 18.9 mm in width, and a thickness of 0.78 mm (type N), 1.29 mm (type A), or 2.38 mm (type C). Once a set of projection parameters (firing angle, flow rate, pressure, etc.) has been validated, the impacting media is projected onto the Aimen specimens. The specimens will deform, resulting in the appearance of a deflection, reflecting the transformation of the kinetic energy of the impacting media into plastic deformation. The face of Description of the invention

[0006] One aim of the invention is to provide a method for characterizing paint compaction on a part which addresses the aforementioned drawbacks.

[0007] To this end, the invention provides a method for characterizing paint compaction on a part, in particular a turbomachine part for an aircraft, in which the characterization method comprises the following steps: a) Application of a layer of paint to the part; b) Position an instrumented Almen test specimen in the vicinity of the part; c) Projection onto the painted part and the instrumented Almen test specimen of an impacting medium to compact the layer of paint applied to the part: d) Measurement of the Almen intensity of the projection using the instrumented Almen test tube; and, e) Characterization of the paint layer thus compacted on the part.

[0008] Advantageously, but optionally, the method according to the invention has at least one of the following technical characteristics: - the process includes an additional step of: f) developing a set of compaction parameters from the Almen intensity measurement and the characterization of the compacted paint layer; steps a) to f) are repeated until an optimal set of compaction parameters associated with the part is obtained; - steps a) to f) are repeated to develop Aimen / microstructure arrow charts from different Almen intensity measurements and different characterizations of the compacted paint layer; - the part is one of a reference test specimen and a turbomachine part; - during step b), several instrumented Almen test specimens are positioned in the vicinity of the part; the instrumented Almen test specimen includes a piezoelectric sensor; the paint layer is an aluminum pigment paint layer with an inorganic binder.

[0009] The invention also provides for a method of compacting paint on a part, in particular a turbomachine part for an aircraft, in which the compaction method includes a preliminary step of implementing a compaction characterization method having at least one of the preceding technical characteristics.

[0010] The invention also provides for a paint compaction installation comprising means for projecting an impacting media, a part and an instrumented Almen test specimen, in which the installation is arranged so as to implement a compaction characterization process having at least one of the preceding technical characteristics.

[0011] Advantageously, but optionally, the installation according to the invention has at least one of the following technical characteristics: - the installation also includes a protective cabin surrounding the projection equipment, the instrumented Almen test specimen and the part; - the protective cabin is soundproofed and includes a suction and filtration system. Brief description of the figures

[0012] Other features and advantages of the invention will become apparent from the following description of an embodiment of the invention. See the attached drawings. [Fig.1] is a schematic view of an installation implementing a method for characterizing paint compaction according to the invention: and, [Fig.2] is a flowchart of a process for characterizing a paint compaction according to the invention.

[0013] For clarity, identical or similar elements are identified by identical reference symbols across all figures.

Claims

7. A method according to any one of claims 1 to 6, wherein the instrumented Aimen test specimen includes a piezoelectric sensor (41).

8. A method according to any one of claims 1 to 7, wherein the paint layer is an aluminum pigment paint layer with an inorganic binder.

9. A method for compacting paint on a part (3), in particular a turbomachine part for an aircraft, wherein the compaction method includes a preliminary step of implementing a compaction characterization method according to any one of claims 1 to 8.

10. Paint compaction installation (1) comprising means for projecting an impacting media (16), a part (3) and an instrumented Aimen test specimen (4), wherein the installation is arranged so as to implement a characterization process according to any one of claims 1 to 8 or a compaction process according to claim 9.

11. Installation according to claim 10, wherein the installation further comprises a protective cabin (10) surrounding the projection means, the instrumented Aimen test specimen and the part.

12. Installation according to claim 11, in which the protective cabin is soundproofed and includes a suction and filtration system (14).

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