Standard part intended to be subject to non-destructive testing

Abstract

Standard part (1, 100, 200), intended to serve as a standard for non-destructive testing or to measure a performance of the non-destructive testing, the standard part being obtained by additive manufacturing, the standard part comprising a defect formed in a controlled manner. Figure for the abstract: Fig. 1

Description

Title of the invention: Standard part intended to be subject to non-destructive testing FIELD OF THE INVENTION

[0001] The present invention relates to the field of non-destructive testing of standard parts. STATE OF THE ART

[0002] There are non-destructive testing methods that can be implemented to check the condition of a manufactured part. Such methods make it possible in particular to detect unwanted defects in a part, for example a crack, without altering the condition of the part.

[0003] These non-destructive testing processes sometimes require calibration. To do this, a special part, called a standard part, is manufactured, which is then subjected to non-destructive testing. In the standard part, a defect is deliberately formed in a controlled manner, in other words an artificial defect which aims to always be as close as possible to a real natural defect in order to best reproduce the most representative and precise calibration conditions possible.

[0004] However, these defects remain “artificial” because they cannot be easily formed in a controlled manner with conventional manufacturing means and be exact reproductions of so-called natural defects. The configurations of standard parts capable of being obtained with such conventional manufacturing means are thus limited. Statement of the invention

[0005] An object of the invention is to overcome the aforementioned drawback.

[0006] This aim is achieved by a standard part, intended to serve as a standard for non-standard control. destructive or to measure a performance of non-destructive testing, the standard part being obtained by additive manufacturing, the standard part comprising a defect formed in a controlled manner.

[0007] The standard part, which constitutes a first object of the present disclosure, may also comprise the following optional characteristics, taken alone or in combination.

[0008] In a first embodiment, the standard part has a surface delimiting a cavity, the surface comprising two sides inclined relative to each other, the two inclined sides being connected to each other by a rectilinear edge forming a bottom of the cavity, the defect being a crack formed at the level of the rectilinear edge by application of a tensile force to the standard part in a direction perpendicular to the edge. straight.

[0009] Optionally, the surface comprises two second sides inclined relative to each other, the two second inclined sides being connected to each other by a second rectilinear edge, the second rectilinear edge being connected to the rectilinear edge and inclined relative to the rectilinear edge.

[0010] Optionally, the surface comprises two third sides inclined relative to each other, the two third inclined sides being connected to each other by a third rectilinear edge, the third rectilinear edge being connected to the rectilinear edge and inclined relative to the rectilinear edge, the rectilinear edge extending between the second rectilinear edge and the third rectilinear edge.

[0011] Optionally, the standard part also has a concave surface opposite the surface delimiting the cavity, the concave surface being devoid of an edge.

[0012] Optionally, the standard part comprises: a first end portion, a second end portion, and a portion thinned relative to the first end portion and the second end portion, and extending between the first end portion and the second end portion, the surface delimiting the cavity being formed in the thinned portion.

[0013] In a second embodiment, the defect is a hole closed on itself located inside the standard part.

[0014] Optionally, which the self-enclosed hole is a flat-bottomed hole.

[0015] A second object of the present disclosure is a method for obtaining a standard part intended to serve as a standard for non-destructive testing, the method comprising additive manufacturing of the standard part, and the formation of a defect in a controlled manner in the standard part.

[0016] Optionally, the standard part is in accordance with the first embodiment of the first object, and the method comprises, after additive manufacturing, pulling the standard part in a direction perpendicular to the straight edge, so as to form the crack.

[0017] A third object of the present disclosure is a method of non-destructive testing of the standard part constituting the first object of the present disclosure or obtained by the method constituting the second object of the present disclosure.

[0018] Optionally, the non-destructive testing method comprises the application to the standard part of at least one of the following testing techniques: penetrant testing, ultrasonic testing, tomography, radiography, eddy current testing. DESCRIPTION OF FIGURES

[0019] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in with regard to the attached drawings in which:

[0020] [Fig. 1] is a perspective view of a standard part according to a first embodiment.

[0021] [Fig.2] is a front view of a surface portion delimiting a cavity in the standard part of [Fig.l].

[0022] [Fig.3] is a sectional view of the standard part of [Fig.l].

[0023] [Fig.4] and [Fig.5] are two schematic views of a standard part according to a second embodiment.

[0024] [Fig.6] is a perspective view of a standard part according to a third method of realization.

[0025] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0026] With reference to [Fig.l], a standard part 1 is shown according to a first embodiment, intended to calibrate a non-destructive test advantageously by penetrant testing or to measure the performance of this non-destructive test means.

[0027] The standard part 1 comprises three parts: a first end part 2, and a second end part 4 opposite the first end part 2, and a thinned part 6 between the end parts 2, 4.

[0028] The first end portion 2 has a first lower surface 8 and a first upper surface 10 opposite the first lower surface 8. The first lower surface 8 and the first upper surface 10 are planar and parallel. The first portion has a thickness called the “first end thickness”, measured in a direction normal to the first lower surface 8. Thus, the first end thickness is the distance which separates the first lower surface 8 from the first upper surface 10.

[0029] Similarly, the second end portion 4 has a second lower surface 12 and a second upper surface 14 opposite the second lower surface 12. The second lower surface 12 and the second upper surface 14 are planar and parallel. The second end portion 4 has a thickness called the "second end thickness", measured in a direction normal to the second lower surface 12. Thus, the second end thickness is the distance which separates the lower surface from the upper surface.

[0030] The second end thickness is equal to the first end thickness. The first lower surface 8 and the second lower surface 12 are coplanar. The first upper surface 10 and the second upper surface 14 are coplanar.

[0031] The thinned portion 6 connects the first end portion 2 to the second end portion 4.

[0032] The thinned portion 6 has different thicknesses, called intermediate thicknesses, which are less than the first end thickness and the second end thickness. The portion 6 is therefore thinned relative to the first end portion 2 and the second end portion 4.

[0033] The thinned portion 6 has a lower surface, called the intermediate lower surface 16, and an upper surface, called the intermediate upper surface 18 opposite the intermediate lower surface 16.

[0034] The intermediate upper surface 18 is connected to the first upper surface 10. A first straight edge 20 is formed at the junction of the curved portion with the first upper surface 10. Similarly, the curved portion is connected to the second upper surface 14. A second straight edge 22 is formed at the junction of the curved portion with the second upper surface 14.

[0035] The second straight edge 22 is parallel to the first straight edge 20.

[0036] The intermediate upper surface 18 is curved and concave. It therefore contributes to the thinned character of the part 6 of the standard part 1. The intermediate upper surface 18 is cylindrical in a broad sense, that is to say it is a ruled surface whose generatrices are all parallel.

[0037] The intermediate upper surface 18 is devoid of an edge.

[0038] The bottom of the intermediate upper surface 18 is formed by a line parallel to the first rectilinear edge 20 and to the second rectilinear edge 22. This bottom line is equidistant from the first rectilinear edge 20 and from the second rectilinear edge 22. This bottom line is shown in [Fig.l] for purely indicative purposes, but does not form an edge.

[0039] The intermediate lower surface 16 comprises two portions: a central portion 24 delimiting a cavity (visible by transparency in [Fig.l]), and a portion 26 surrounding the central portion 24, called the surrounding portion 26.

[0040] The surrounding portion 26 is connected to the first lower surface 8, and to the second lower surface 12.

[0041] The surrounding portion 26 is planar, and coplanar with the first lower surface 8 and with the second lower surface 12. Thus, the first lower surface 8, the surrounding portion 26 of the intermediate lower surface 16 and the second lower surface 12 together form a planar surface of the standard part 1.

[0042] The central portion 24 constitutes a frangible zone of the standard part. The central portion 24 delimits a cavity opening into the intermediate lower surface 16. The central portion 24 therefore contributes to the thinning character of the part 6 of the standard part 1.

[0043] The upper intermediate surface 18, which is concave, is opposite the surface central 24.

[0044] With reference to [Fig.2] and [Fig.3], the central portion 24 delimiting the cavity is connected to the surrounding surface 26 by an edge closed on itself forming a perimeter of the cavity.

[0045] The central portion 24 comprises two main faces 30, 32 inclined relative to each other. The two inclined main faces 30, 32 are connected to each other by a main rectilinear edge 34 which forms a bottom of the cavity. These characteristics make it possible to promote the appearance of a localized crack at the level of the rectilinear edge.

[0046] Each of the two inclined sides 30, 32 is rectangular.

[0047] The main rectilinear edge 34 forming the bottom of the cavity is parallel to the surrounding surface 26.

[0048] Furthermore, the main rectilinear edge 34 is parallel to the first rectilinear edge 20 and to the second rectilinear edge 22 forming a junction between the thinned part 6 and the two end parts of the standard part 1.

[0049] The main rectilinear edge 34 advantageously has a length of between 1 and 3 millimeters, for example 2 millimeters.

[0050] The central portion 24 delimiting the cavity further comprises two secondary sides 36, 38 inclined relative to each other, the two secondary sides 36, 38 being connected to each other by a secondary rectilinear edge 40, the secondary rectilinear edge 40 being connected to the main rectilinear edge 34 at a junction point, and inclined relative to the main rectilinear edge 34. Thus, the secondary rectilinear edge 40 extends the main rectilinear edge 34.

[0051] The two secondary sides 36, 38 are triangular.

[0052] The straight edge 40 is inclined at an angle of less than 45 degrees relative to the main straight edge 34 (assuming that if this angle were 0 degrees, the two edges would be parallel).

[0053] The secondary rectilinear edge 40 is the complement to the edge 34 allowing it to connect to the plane formed by 26.

[0054] The central portion 24 delimiting the cavity further comprises two other secondary sides 42, 44 inclined relative to each other, the two other secondary sides 42, 44 being connected to each other by another secondary rectilinear edge 46, the other secondary rectilinear edge 46 being connected to the main rectilinear edge 34 at another junction point, and inclined relative to the main rectilinear edge 34. Thus, the other secondary rectilinear edge 46 extends the main rectilinear edge 34.

[0055] The two other secondary sides 42, 44 are triangular.

[0056] The other straight edge 46 is inclined at an angle of less than 45 degrees relative to the main straight edge 34 (assuming that if this angle were 0 degrees, the two edges would be parallel).

[0057] The other secondary rectilinear edge 46 is the complement to the edge 34 allowing it to connect to the plane formed by 26.

[0058] The secondary sides 36, 38 and the other secondary sides 42, 44 are symmetrical.

[0059] The main straight edge 34 extends between the secondary straight edge 40 and the other secondary straight edge 46, and connects them to each other.

[0060] The main rectilinear edge 34, and the two secondary rectilinear edges 40, 46 are coplanar. [Fig.3] shows a section of the standard part 1 in the plane in which these edges 34, 40, 46 extend. This section is a section of minimum thickness of the standard part 1. It is in fact in this plane that the thickness of the part 1 is minimum.

[0061] As indicated previously, the standard part 1 is obtained by additive manufacturing. Additive manufacturing is for example of the powder bed fusion type, in particular of the selective laser melting (SLM) type.

[0062] The standard part 1 is made of a metallic material. The manufacturing therefore uses metallic powder.

[0063] The standard part 1 further comprises a defect formed in a controlled manner. In this embodiment, the defect is a crack formed at the level of the straight edge during a tensile step subsequent to the additive manufacturing of the standard part 1.

[0064] During this traction step, a traction tool is used comprising: • two first jaws gripping the first end part 2 (one of the jaws coming into contact with the first upper surface 10 and the other jaw coming into contact with the first lower surface 8); and • two second jaws gripping the second end part 4 (one of the jaws coming into contact with the second upper surface 14 and the other jaw coming into contact with the second lower surface 12).

[0065] The traction tool applies a traction force to the standard part 1 in a direction perpendicular to the rectilinear edge 34. This force tends to move the first end part 2 away from the second end part 4. The traction force makes it possible to locally exceed the breaking limit of the material in which the standard part 1 is made, and therefore to cause it to crack.

[0066] During this traction, the crack discussed previously forms at the level of the rectilinear edge 34. The concave and edgeless character of the upper surface 18 helps to concentrate stresses at the level of this edge.

[0067] If the tensile force is sufficiently high, the crack can cross the two junction points constituting the ends of the main rectilinear edge 34, and extend along the secondary edges which extend the main rectilinear edge 34. The fact that the secondary edges 40, 46 are inclined relative to the main rectilinear edge 34 allows for more precise control of crack length.

[0068] It should be noted that the secondary rectilinear edges 40, 46 make it possible to reduce the risk of breakage of the standard part during the traction step.

[0069] In practice, the crack can be observed along the bottom line of the intermediate upper surface 18, facing the straight main edge 34. The crack has been represented in [Fig.2] by an irregular line.

[0070] It could be considered to form the crack during additive manufacturing. However, it is difficult to obtain a realistic crack by additive manufacturing. Although it is possible to program the obtaining of "a very thin void" by additive manufacturing, this volume of lack of material will not exactly resemble a natural cracking of the material. Forming the crack during the subsequent tensile step has the advantage of allowing a realistic crack to be obtained.

[0071] The standard part 1 thus obtained can then be used during a non-destructive testing process.

[0072] For example, this non-destructive testing method includes penetrant testing.

[0073] During the penetrant testing, the standard part 1 is coated with a penetrant, in particular on the intermediate upper surface 18 where the crack can be observed (due to the absence of an edge which would form an interpretation artifact). Then, the observation of the standard part is carried out, while the part is illuminated by natural light in the case of colored penetrant or by ultraviolet light in the case of fluorescent penetrant.

[0074] It will be noted that the absence of an edge on the intermediate upper surface 18 limits the risk of the appearance of a visual artifact, making it possible not to hinder the highlighting of the crack revealed by penetrant testing. Here we see the full advantage of this type of standard making it possible to improve the calibration in penetrant testing.

[0075] Alternatively or additionally, the non-destructive testing method comprises at least one of the following techniques: ultrasonic testing, tomography, eddy current testing, thermography and / or ultrasonic resonance spectroscopy.

[0076] With reference to [Fig.4] and [Fig.5], a standard part 100 is shown according to a second embodiment intended to be the subject of calibration for non-destructive testing, advantageously by ultrasound.

[0077] The standard part 100 has a lower surface and an upper surface opposite the lower surface. The lower surface and the upper surface are flat and parallel. The standard part has a parallelepiped shape (which implies the presence of four lateral surfaces in addition to the lower surface and the upper surface). Alternatively, the standard part 100 may have a more complex shape, for example the shape of an aerodynamic part for a turbomachine.

[0078] As in the first embodiment, the standard part 100 is obtained by additive manufacturing, and the standard part 100 comprises a defect formed in a controlled manner.

[0079] In this second embodiment, the defect is formed during additive manufacturing, and not subsequently as in the first embodiment, and has a different shape.

[0080] In this second embodiment, the defect is a hole 102 closed on itself, located inside the standard part 100.

[0081] The self-closing hole is a flat-bottomed hole 102.

[0082] The flat-bottomed hole is, for example, cylindrical in shape. It is delimited by a bottom surface, a ceiling surface opposite the bottom surface, and a cylindrical side surface.

[0083] The bottom surface may be parallel to the lower surface (as shown in figure [Fig.4]) or not (see [Fig.5]).

[0084] Additive manufacturing makes it easy to form such a self-enclosed hole 102, unlike other methods requiring drilling of the part to form a hole inside. Such drilling would leave a passage opening into the hole and to the outside of the part. However, a passage would be likely to disrupt the non-destructive testing carried out on the part subsequently, especially if this testing involves the emission of a wave towards the part. Since the hole 102 formed by additive manufacturing is closed, a subsequent non-destructive testing is not subject to this problem.

[0085] Another advantage of additive manufacturing is the ease of forming the flat-bottomed hole in any orientation.

[0086] This standard part 100 can be subjected to non-destructive testing comprising at least one of the techniques mentioned in relation to the first embodiment, but is particularly suitable for testing involving the emission of a wave on the part (in particular with an ultrasonic technique, involving the emission of an ultrasonic wave on the part, or in radiography or tomography). In the example of [Fig.4], the wave is emitted in a direction normal to the bottom surface of the hole 102. In the example of [Fig.5], the direction of the wave forms an angle greater than 0° relative to this normal direction.

[0087] Alternatively, the standard part 100 could be a more complete part for the purpose of measuring the performance of non-destructive testing on real parts with the intention of providing sizing curves associated with the detection performance of each of the areas of the parts.

[0088] [Fig.6] shows a standard part 200 intended to be calibrated for non-destructive testing, advantageously by eddy current according to a third embodiment. Here again, the standard part is obtained by additive manufacturing and the standard part comprises a defect formed in a controlled manner. In this third embodiment, the standard part is a shim comprising a plurality of through holes of different diameters. The defect is a sub-surface defect. This part can be subjected to non-destructive testing comprising at least one of the techniques mentioned in relation to the first embodiment, but is particularly suitable for eddy current testing.

[0089] Other standard parts are possible, with different types of defects obtained in a controlled manner, in particular: • a stacking defect of layers formed during additive manufacturing. Such a defect may aim to characterize additive manufacturing, particularly when this manufacturing is of the SLM type. • a porosity defect intentionally obtained by using incorrect SLM firing parameters for the additive manufacturing of the part. Such a defect may be intended to assess the capability of non-destructive testing such as X-ray radiography, i.e. by introducing porosity variability to test the detection limit. • a bubble or vacuum programmed and incorporated during additive manufacturing.

Claims

Claims

1. Standard part (1, 100, 200), intended to serve as a standard for non-destructive testing or to measure a performance of the non-destructive testing, the standard part being obtained by additive manufacturing, the standard part comprising a defect formed in a controlled manner.

2. Standard part (1) according to the preceding claim, having a surface (24) delimiting a cavity, the surface (14) comprising two inclined sides (30, 32) relative to each other, the two inclined sides (30, 32) being connected to each other by a rectilinear edge (34) forming a bottom of the cavity, the defect being a crack formed at the level of the rectilinear edge by application of a tensile force to the standard part (1) in a direction perpendicular to the rectilinear edge (34).

3. Standard part (1) according to the preceding claim, in which the surface (24) comprises two second sides (36, 38) inclined relative to each other, the two second inclined sides (36, 38) being connected to each other by a second rectilinear edge (40), the second rectilinear edge (40) being connected to the rectilinear edge (34) and inclined relative to the rectilinear edge (34).

4. Standard part (1) according to the preceding claim, in which the surface comprises two third inclined faces (42, 44) with respect to each other, the two third inclined faces (42, 44) being connected to each other by a third rectilinear edge (46), the third rectilinear edge (46) being connected to the rectilinear edge (34) and inclined with respect to the rectilinear edge (34), the rectilinear edge (34) extending between the second rectilinear edge (40) and the third rectilinear edge (46).

5. Standard part (1) according to any one of claims 2 to 4, furthermore having a concave surface (18) opposite the surface delimiting the cavity, the concave surface being devoid of an edge.

6. Standard part (1) according to any one of claims 2 to 5, comprising: • a first end portion (2), • a second end portion (4), • a thinned portion (6) relative to the first end portion (2) and to the second end portion (4), and extending between the first end portion (2) and the second end portion (4), the surface delimiting (24) the cavity being formed in the thinned portion (6).

7. A standard part (100) according to claim 1, wherein the defect is a self-enclosed hole located inside the standard part.

8. Standard part (100) according to the preceding claim, in which the hole closed on itself is a flat-bottomed hole.

9. A method of obtaining a standard part (1, 100, 200) intended to serve as a standard for non-destructive testing, the method comprising additive manufacturing of the standard part (1, 100, 200), and the formation of a defect in a controlled manner in the standard part (1, 100, 200).

10. Production method according to the preceding claim, in which the standard part (1) conforms to any one of claims 2 to 6, the method comprising, after additive manufacturing, pulling the standard part (1) in a direction perpendicular to the rectilinear edge, so as to form the crack.

11. Method for non-destructive testing of a standard part according to any one of claims 1 to 8 or obtained by a method according to any one of claims 9 and 10, comprising the application to the standard part (1, 100, 200) of at least one of the following testing techniques: • penetrant testing, • ultrasonic testing, • tomography, • radiography, • eddy current testing.

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