Standard piece for being subjected to non-destructive testing

Abstract

A standard part (1, 100, 200) used as a standard for nondestructive testing or for measuring the performance of nondestructive testing, the standard part being obtained by additive manufacturing, including defects formed in a controlled manner.

Description

Technical Field

[0001] This disclosure relates to the field of nondestructive testing of standard parts. Background Technology

[0002] There are existing non-destructive testing methods that can be used to assess the condition of manufactured parts. In particular, these methods allow for the detection of defects, such as cracks, in parts without damaging their condition.

[0003] These nondestructive testing methods sometimes require calibration. For this purpose, a special part called a standard is manufactured and subjected to nondestructive testing. Defects (in other words, artificial defects) are intentionally created in the standard in a controlled manner to approximate real natural defects as consistently as possible, in order to best reproduce the most representative and accurate calibration conditions.

[0004] However, these defects are still "artificial" because they cannot be easily formed in a controlled manner using traditional manufacturing methods, nor can so-called natural defects be precisely replicated. Therefore, the standard part structures that can be obtained through the aforementioned traditional manufacturing methods are limited. Summary of the Invention

[0005] One object of the present invention is to overcome the above-mentioned disadvantages.

[0006] This objective is achieved by a standard component intended to serve as a standard for nondestructive testing or to measure the performance of nondestructive testing, said standard component being obtained through additive manufacturing and including defects formed in a controlled manner.

[0007] The standard components that constitute the first subject of this disclosure may also include optional features, either individually or in combination.

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

[0009] Optionally, the surface includes two second side surfaces that are inclined relative to each other, the two inclined second side surfaces being connected to each other by a second straight edge, the second straight edge being connected to the straight edge and inclined relative to the straight edge.

[0010] Optionally, the surface includes two mutually inclined third side surfaces connected to each other by a third straight edge, the third straight edge being connected to the straight ridge and inclined relative to the straight edge, the straight edge extending between the second straight edge and the third straight edge.

[0011] Optionally, the standard part also has a concave surface opposite the surface defining the cavity, the concave surface having no edges.

[0012] Optionally, the standard part includes a first end, a second end, and a thinned portion relative to the first and second ends, the thinned portion extending between the first and second ends, and the surface defining the cavity is formed in the thinned portion.

[0013] In the second embodiment, the defect is a self-sealing hole located inside the standard part.

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

[0015] The second subject of this disclosure is a method for obtaining a standard part intended to be used as a standard for nondestructive testing, the method comprising manufacturing the standard part by additive manufacturing and forming defects in the standard part in a controlled manner.

[0016] Optionally, the standard part conforms to the first embodiment of the first subject matter, and the method after additive manufacturing includes applying a tensile force to the standard part in a direction perpendicular to the straight edge to form a crack.

[0017] The third subject of this disclosure is a non-destructive testing method for standard parts used in the first subject of this disclosure or for standard parts obtained by the method of forming the second subject of this disclosure.

[0018] Optionally, nondestructive testing methods include applying at least one of the following testing techniques to standard parts: penetrant testing, ultrasonic testing, tomography, radiography, and eddy current testing. Attached Figure Description

[0019] Other features, objects, and advantages of the invention will become apparent from the following illustrative and non-limiting description, which should be read in conjunction with the accompanying drawings, wherein: Figure 1 This is a perspective view of a standard part according to the first embodiment.

[0020] Figure 2 It is a definition Figure 1 A front view of a portion of the surface of a cavity in a standard part.

[0021] Figure 3 yes Figure 1 A sectional view of a standard Chinese component.

[0022] Figure 4 and Figure 5 This is a schematic diagram of a standard component according to the second embodiment.

[0023] Figure 6 This is a perspective view of a standard part according to the third embodiment.

[0024] In all the accompanying drawings, similar elements are labeled with the same reference numerals. Detailed Implementation

[0025] Reference Figure 1 The illustration shows a standard component according to the first embodiment, which is intended to calibrate nondestructive testing (advantageously by penetrant testing) or measure the performance of the nondestructive testing device.

[0026] The standard part 1 comprises three parts: a first end 2 and a second end 4 opposite to the first end 2, and a thinned portion 6 located between the ends 2 and 4.

[0027] The first end portion 2 has a first bottom surface 8 and a first top surface 10 opposite to the first bottom surface 8. The first bottom surface 8 and the first top surface 10 are flat and parallel to each other. The first portion has a so-called "first end thickness," which is measured in a direction perpendicular to the first bottom surface 8. Therefore, the first end thickness is the distance between the first bottom surface 8 and the first top surface 10.

[0028] Similarly, the second end portion 4 has a second bottom surface 12 and a second top surface 14 opposite to the second bottom surface 12. The second bottom surface 12 and the second top surface 14 are flat and parallel to each other. The second end portion 4 has a so-called "second end portion thickness" measured in a direction perpendicular to the second bottom surface 12. Therefore, the second end portion thickness is the distance between the bottom surface and the top surface.

[0029] The thickness of the second end is equal to the thickness of the first end. The first bottom surface 8 and the second bottom surface 12 are coplanar. The first top surface 10 and the second top surface 14 are coplanar.

[0030] The thinned portion 6 connects the first end 2 to the second end 4.

[0031] The thinned portion 6 has a different thickness, referred to as the intermediate thickness, which is narrower than the thickness of the first end and the second end. Therefore, portion 6 is thinned relative to the first end 2 and the second end 4.

[0032] The thinned portion 6 has a bottom surface called intermediate bottom surface 16 and a top surface called intermediate top surface 18 opposite to intermediate bottom surface 16.

[0033] The intermediate top surface 18 is connected to the first top surface 10. A first straight edge 20 is formed at the junction between the curved portion and the first top surface 10. Similarly, the curved portion is connected to the second top surface 14. A second straight edge 22 is formed at the junction between the curved portion and the second top surface 14.

[0034] The second straight side 22 is parallel to the first straight side 20.

[0035] The intermediate top surface 18 is curved and concave. Therefore, it contributes to the thinning characteristics of part 6 of standard part 1. The intermediate top surface 18 is generally cylindrical, that is, it is a regular surface where all generatrices are parallel to each other.

[0036] The top surface 18 in the middle has no edges.

[0037] The bottom of the middle top surface 18 is formed by a line parallel to the first straight edge 20 and the second straight edge 22. This bottom line is equidistant from the first straight edge 20 and the second straight edge 22. Figure 1 This bottom line is shown for guidance purposes only, but it does not constitute a boundary.

[0038] The intermediate bottom surface 16 comprises two parts: a central portion 24 defining the cavity (in Figure 1 (The portion 24 is shown in a transparent manner) and the portion 26 surrounding the central portion 24 are called the surrounding portion 26.

[0039] The surrounding portion 26 is connected to the first bottom surface 8 and the second bottom surface 12.

[0040] The surrounding portion 26 is flat and coplanar with the first bottom surface 8 and the second bottom surface 12. Therefore, the surrounding portion 26 of the first bottom surface 8, the middle bottom surface 16, and the second bottom surface 12 together form the flat surface of the standard part 1.

[0041] The central portion 24 constitutes a vulnerable area of ​​the standard part. The central portion 24 defines a cavity leading to the intermediate bottom surface 16. Therefore, the central portion 24 contributes to the thinning characteristics of part 6 of the standard part 1.

[0042] The concave top surface 18 is opposite to the central surface 24.

[0043] refer to Figure 2 and Figure 3 The central portion 24 of the cavity is connected to the surrounding surface 26 by an edge, which together form the periphery of the cavity.

[0044] The central portion 24 includes two main side surfaces 30 and 32, each inclined relative to the other. The two inclined main side surfaces 30 and 32 are interconnected by a main straight edge 34 forming the bottom of the cavity. These characteristics facilitate the formation of localized cracks at the straight edge.

[0045] Each of the two sloping sides 30 and 32 is a rectangle.

[0046] The main straight edge 34 forming the bottom of the cavity is parallel to the surrounding surface 26.

[0047] Furthermore, the main straight edge 34 is parallel to the first straight edge 20 and the second straight edge 22 at the connection between the two ends forming the thinned portion 6 and the standard part 1.

[0048] The length of the main straight edge 34 is advantageously between 1 mm and 3 mm, for example 2 mm.

[0049] The central portion 24 defining the cavity also includes two secondary side surfaces 36 and 38 that are inclined relative to each other. These two secondary side surfaces 36 and 38 are connected to each other by a secondary straight edge 40, which connects to the main straight edge 34 at a joint point and is inclined relative to the main straight edge 34. Therefore, the secondary straight edge 40 extends the main straight edge 34.

[0050] The two secondary sides, 36 and 38, form a triangle.

[0051] The straight edge 40 is tilted at an angle of less than 45 degrees relative to the main straight edge 34 (the principle is that if the angle is 0 degrees, the two edges will be parallel).

[0052] Secondary straight edge 40 is a complement to edge 34, thereby connecting it to the plane formed by 26.

[0053] The central portion 24 defining the cavity also includes two additional secondary side surfaces 42 and 44 that are inclined relative to each other. These two additional secondary side surfaces 42 and 44 are connected to each other by another secondary straight edge 46, which is connected to the main straight edge 34 at another connection point and is inclined relative to the main straight edge 34. Therefore, the other secondary straight edge 46 extends from the main straight edge 34.

[0054] The two additional secondary sides, 42 and 44, are triangular.

[0055] The other straight edge 46 is tilted at an angle of less than 45 degrees relative to the main straight edge 34 (the principle is that if the angle is 0 degrees, the two edges will be parallel).

[0056] Another secondary straight edge 46 is the complementary edge of edge 34, thus it connects to the plane formed by 26.

[0057] Secondary sides 36 and 38 are symmetrical with other secondary sides 42 and 44.

[0058] The main straight edge 34 extends between the secondary straight edge 40 and another secondary straight edge 46, connecting the two together.

[0059] The main straight edge 34 and the two secondary straight edges 40 and 46 are coplanar. Figure 3 The cross-section of standard part 1 in the plane extending from these edges 34, 40, and 46 is shown. This cross-section represents the minimum thickness of standard part 1. In fact, it is precisely in this plane that the thickness of standard part 1 is minimal.

[0060] As previously mentioned, standard part 1 is obtained through additive manufacturing. Additive manufacturing, for example, is of the powder bed melting type, particularly selective laser melting (SLM).

[0061] Standard part 1 is made of metal. Therefore, it is manufactured using metal powder.

[0062] Standard part 1 also includes defects formed in a controlled manner. In this embodiment, the defect is a crack formed at the straight edge during a tensile testing step after additive manufacturing of standard part 1.

[0063] In this tensile testing procedure, the tensile fixtures used include: - Two first clamps, clamping the first end 2 (one clamp contacts the first top surface 10, and the other clamp contacts the first bottom surface 8); and - Two second clamps hold the second end 4 (one clamp contacts the second top surface 14, and the other clamp contacts the second bottom surface 12).

[0064] A tensioning fixture applies a tensile force to the standard part 1 in a direction perpendicular to the straight edge 34. This force tends to pull the first end 2 away from the second end 4. The tensile force causes local areas of the material of the standard part 1 to exceed its fracture strength, thereby resulting in cracks.

[0065] Throughout the application of tensile force, the previously discussed crack forms at straight edge 34. The concave structure and edge absence of the top surface 18 contribute to stress concentration at this edge.

[0066] If the tensile force is large enough, the crack can extend beyond the two connection points forming the end of the main straight edge 34 and propagate along the secondary edges that continue from the main straight edge 34. Since the secondary edges 40 and 46 are inclined relative to the main straight edge 34, this means that the crack length can be measured more accurately.

[0067] It should be noted that secondary straight edges of 40 and 46 help reduce the risk of breakage of standard parts during tensile testing.

[0068] In practice, the crack can be observed along the bottom line of the middle top surface 18 facing the main straight edge 34. This crack... Figure 2 It is represented by an irregular line.

[0069] It is conceivable to form cracks during additive manufacturing. However, obtaining realistic cracks through additive manufacturing is difficult. Although it is possible to plan to obtain "very thin voids" through additive manufacturing, such materialless spaces do not entirely resemble the natural cracking of a material. Forming cracks in subsequent tensile testing steps has the advantage of obtaining realistic cracks.

[0070] The standard part 1 obtained in this way can then be used for non-destructive testing methods.

[0071] For example, this non-destructive testing method includes penetrant testing.

[0072] For penetrant testing, standard part 1 is coated with a liquid penetrant, particularly on the central top surface 18 where the crack is visible (since there are no edges that would be interpreted as artifacts). The standard part is then placed under observation; if the penetrant is stained, the part is illuminated with natural light; if the penetrant is fluorescent, it is illuminated with ultraviolet light.

[0073] It should be noted that the absence of sharp edges on the central top surface 18 limits the risk of visual artifacts that could hinder the identification of cracks revealed by penetrant testing. This highlights the full advantage of this standard component, allowing for improved calibration through penetrant testing.

[0074] Alternatively or additionally, nondestructive testing methods include at least one of the following techniques: ultrasonic testing, tomography, eddy current testing, thermal imaging, and / or resonant ultrasonic spectroscopy.

[0075] refer to Figure 4 and Figure 5 The diagram shows a standard component 100 according to a second embodiment, which is intended as a calibration object for non-destructive testing (advantageously ultrasonic testing).

[0076] Standard part 100 has a bottom surface and a top surface opposite the bottom surface. The bottom and top surfaces are flat and parallel to each other. The standard part is a parallelepiped shape (including four sides in addition to the bottom and top surfaces). As a variation, standard part 100 may have a more complex shape, such as the shape of a pneumatic component of a turbine engine.

[0077] Similar to the first embodiment, the standard part 100 is obtained by additive manufacturing, and the standard part 100 includes defects formed in a controlled manner.

[0078] In this second embodiment, the defects are formed during the additive manufacturing process, rather than after additive manufacturing as in the first embodiment, and they take on a different form.

[0079] In this second embodiment, the defect is the self-sealing hole 102, which is located inside the standard part 100.

[0080] The self-sealing hole is a flat-bottomed hole 102.

[0081] For example, a flat-bottomed hole is cylindrical. It is defined by a bottom surface, a top surface opposite the bottom surface, and a cylindrical side surface.

[0082] The bottom surface can be parallel to the bottom surface (e.g.) Figure 4 As shown), they can also be non-parallel (see...). Figure 5 ).

[0083] Additive manufacturing can easily form the self-sealing hole 102, while other methods require perforating the standard part to form the hole internally. This perforation leaves a through-channel leading to both the inside of the hole and the outside of the standard part. However, this channel can interfere with subsequent non-destructive testing of the standard part, especially when the testing involves projecting waves onto the part. The hole 102 formed by additive manufacturing is closed, therefore this problem is not encountered during subsequent non-destructive testing.

[0084] Another advantage of additive manufacturing is that it can easily form flat-bottomed holes in any direction.

[0085] The standard part 100 can be used as an object for non-destructive testing, including at least one technique related to the first embodiment, but is particularly suitable for tests involving the emission of waves to the part (especially ultrasonic techniques, radiography, or tomography). Figure 4 In the example, the wave is emitted in a direction perpendicular to the bottom surface of aperture 102. Figure 5 In the example, the direction of the wave forms an angle greater than 0° with the direction of the normal.

[0086] As a variant, Standard Part 100 can be a more complete part used to measure the performance of nondestructive testing performed on an actual part, with the aim of providing dimensional curves related to the performance of each region in the tested part.

[0087] According to the third embodiment, Figure 6 A standard part 200 is shown, intended as an object for nondestructive testing calibration (advantageously by eddy current testing). This standard part is also obtained by additive manufacturing, and it contains defects formed in a controlled manner. In this third embodiment, the standard part is a gasket comprising multiple through holes of different diameters. The defect is a near-surface defect. This standard part can serve as an object for nondestructive testing incorporating at least one technique mentioned in the first embodiment, but is particularly suitable for eddy current testing.

[0088] Other standard parts can be envisioned, which have different types of defects obtained in a controlled manner, in particular: - Delamination defects formed during the additive manufacturing process. The purpose of these defects can be to characterize additive manufacturing, particularly SLM-type additive manufacturing.

[0089] - Porosity defects intentionally obtained through additive manufacturing of parts using incorrect SLM scanning parameters. The purpose of these defects may be to evaluate the capability of X-ray radiographic nondestructive testing, i.e., to test the detection limits by incorporating variable porosity.

[0090] - Pre-set bubbles or voids added during the additive manufacturing process.

Claims

1. A standard part (1, 100, 200) intended for use as a standard for nondestructive testing or to measure the performance of nondestructive testing, said standard part being obtained by additive manufacturing, said standard part including defects formed in a controlled manner.

2. The standard part (1) according to the preceding claim has a surface (24) defining a cavity, the surface (14) including two sides (30, 32) inclined to each other, the two inclined sides (30, 32) being connected to each other by a straight edge (34) forming the bottom of the cavity, the defect being a crack formed at the straight edge by applying a tensile force to the standard part (1) in a direction perpendicular to the straight edge (34).

3. Standard part (1) according to the preceding claim, wherein The surface (24) includes two second side surfaces (36, 38) that are inclined relative to each other, the two inclined second side surfaces (36, 38) being connected to each other by a second straight edge (40), the second straight edge (40) being connected to a straight edge (34) and inclined relative to the straight edge (34).

4. Standard part (1) according to the preceding claim, wherein The surface includes two third side surfaces (42, 44) that are inclined relative to each other, the two inclined third side surfaces (42, 44) being connected to each other by a third straight edge (46), the third straight edge (46) being connected to a straight edge (34) and inclined relative to the straight edge (34), the straight edge (34) extending between the second straight edge (40) and the third straight edge (46).

5. The standard part (1) according to any one of claims 2 to 4 further has a concave surface (18) opposite to the surface defining the cavity, said concave surface having no edges.

6. The standard part (1) according to any one of claims 2 to 5, comprising: - First end (2) - Second end (4) - A thinning portion (6) relative to the first end (2) and the second end (4), the thinning portion extending between the first end (2) and the second end (4), and a surface (24) defining the cavity is formed in the thinning portion (6).

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

8. The standard part (100) according to the preceding claim, wherein The self-sealing hole is a flat-bottomed hole.

9. A method of obtaining a standard piece (1, 100, 200) intended to be used as a standard for non-destructive testing, the method comprising: The standard parts (1, 100, 200) are manufactured by additive manufacturing, and defects are formed in the standard parts (1, 100, 200) in a controlled manner.

10. The method according to the preceding claim, wherein, The standard part (1) conforms to any one of claims 2 to 6, and the method after additive manufacturing includes: applying a tensile force to the standard part (1) in a direction perpendicular to the straight edge to form a crack.

11. Non-destructive testing method for a standard piece according to any one of claims 1 to 8, or for a standard piece obtained by the method of any one of claims 9 and 10, comprising: Apply at least one of the following inspection techniques to standard parts (1, 100, 200): - Penetration testing, - Ultrasonic testing. -Computed tomography, - X-ray photography - Eddy current detection.

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