Method for estimating the lifespan of an additively manufactured aeronautical part and an assembly comprising the part and a test piece

Abstract

TITLE IN APPBODY-TITLE One aspect of the invention relates to an assembly comprising an aeronautical part comprising a first portion composed of a material resulting from additive manufacturing from a powder and a test piece composed of a material identical to the material of the first portion of the aeronautical part, the test piece 3 comprising two fixing heads 31 and a central portion 30 extending between the two fixing heads 31, the central portion 30 and the part being of shape and dimension identical to the shape and dimension. Figure to be published with the abstract: Figure 4

Description

Title of the invention: Method for estimating the lifespan of an additively manufactured aeronautical part and an assembly comprising the part and a test piece TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of estimating the lifespan of an additive manufacturing part in the field of aeronautics, in particular turbomachines.

[0002] The present invention relates to a method for estimating the lifespan of an additive manufacturing part and in particular a part produced by a selective laser melting printing process. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] In the field of aeronautics, in particular turbomachines, in aeronautics, more and more turbomachine parts are manufactured by an additive manufacturing process such as the selective laser melting printing process.

[0004] Generally speaking, to characterize a material, it is known to use a test piece representative of the material to be characterized, to install this test piece on a test bench and to subject it to tests and trials representative of the conditions to which the material will be subjected when the turbomachine is in operation.

[0005] To calculate the lifetime of a part, there are finite element calculation methods based on the characteristics of the material.

[0006] The advantage of the additive manufacturing process makes it possible to produce parts with one or more very complex shapes and possibly thin thicknesses (less than 2 mm). These shapes may also have an inaccessible surface and therefore difficult to measure in series using conventional dimensional control means. In addition, due to inaccessibility, the surface conditions may be required to remain as manufactured (certain areas cannot be machined), with localized significant levels of roughness. These different parameters mean that the thickness actually manufactured cannot be measured on each part. This may therefore present a certain variability (for example, greater than 10%).In fact, there is a manufacturing tolerance dimension chain which is equal to a tolerance of the additive manufacturing process + tolerance of the cutting of the separation wire of the plate + possibly the tolerances of the subsequent manufacturing operations such as machining, turning etc. In addition, the complex shape associated with a low thickness and possibly particular surface conditions induces a lack of representativeness between the traditional test pieces used to establish the material lines (cylindrical test piece. of diameter approximately equal to 4mm) and the particular area of ​​the part. All these constraints prevent finite element calculations from being carried out.

[0007] A known expensive solution for these parts is to carry out engine tests (very expensive in the aeronautical field) which allow the part to be tested in its overall environment.

[0008] There is therefore a real need for a characterization technique to enable, at low cost, the evaluation (calculation or mechanical testing) of the robustness and / or the service life of a part having an area with a so-called complex shape and / or dimension (i.e. one that cannot be considered representative of traditional cylindrical mechanical characterization specimens) produced by an additive manufacturing process during the dimensioning phase. Summary of the invention

[0009] The invention offers a solution to the problems mentioned above, by making it possible to carry out mechanical or thermomechanical tests on an area that is too complex to calculate a lifetime per finite element.

[0010] A first aspect of the invention relates to an assembly comprising: • an aeronautical part comprising a first portion having a shape composed of a material resulting from additive manufacturing from a powder, • a test piece composed of a material identical to the material of the first portion of the aeronautical part, the test piece comprising two fixing heads and a central portion extending between the two fixing heads, the central portion being of shape and dimension identical to the shape and dimension of a part of the first portion of the aeronautical part.

[0011] Thanks to the invention, it is possible to easily determine a lifetime of an area of ​​a part even if it comprises complex parts having a shape and / or a dimension with high variability, thanks to additive manufacturing for the shape or because of additive manufacturing for the dimension.

[0012] By complex part having a complex shape is meant a volumetric shape that cannot be considered representative of traditional cylindrical mechanical characterization specimens. Thus, the boundary conditions cannot easily be imposed in a finite element model. A wall of a complex part includes an unknown thickness or at least a rough surface state that is not accessible from the outside for inspection. Thus, a complex part has mechanical characteristics that are easier and less expensive to calculate by testing and manufacturing a specimen than by finite element calculation since the internal surface is difficult to grasp by simulation. For example, a complex shape can be a shape of a wall forming a closed internal volume with walls inside high curvature tolerance (not measurable) formed by an additive manufacturing process or a wall comprising an internal surface delimiting a portion of a closed or open cavity whose wall thickness is less than 10 times the roughness Ra of the internal rough surface. In the case of an open cavity, the portion comprises an undercut wall partially closing the volume by forming a section at the opening less than that measured between two faces of the internal rough surface. This complex shape and / or dimension (here thickness) prevents on the one hand the part from being produced by molding or from machining the rough surface.

[0013] By composed of a material resulting from additive manufacturing from a powder, we mean that the part was produced by additive manufacturing from a powder and therefore that it includes traces of this manufacturing process.

[0014] By "test piece composed of a material identical to the material of the first portion of the aeronautical part" is meant that the test piece is made from the same material or the same material and by the same manufacturing process.

[0015] In addition to the characteristics which have just been mentioned in the preceding paragraph, the assembly according to one aspect of the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations:

[0016] According to one embodiment, the central part of the test piece has the same shape as a section of part of the first portion. According to one example, the section is a radial section and the first portion has a shape of revolution around an axis.

[0017] According to one embodiment, the first portion and the central portion are made of a material resulting from additive manufacturing from a powder.

[0018] According to one embodiment, the first portion comprises a wall comprising a thickness less than 7 times a roughness Ra of one of the surfaces of the first portion. Indeed, a tolerance dimension chain exists during the separation of the wall from the plate, equal to the tolerance of the additive manufacturing process + a tolerance of the separation wire cutting of the plate. Furthermore, in the case where machining is carried out on a surface of this wall, the tolerance dimension chain further comprises the tolerance of the machining operation, for example that of turning. This characteristic results in too large an unknown in thickness to be able to carry out a finite element calculation.

[0019] According to one embodiment, the aeronautical part is entirely composed of a material resulting from additive manufacturing from a powder.

[0020] According to one embodiment, the aeronautical part is a part of a turbomachine, for example a distributor.

[0021] According to one embodiment, the aeronautical part comprises other first portions each of which may have a different shape and / or dimension and in that the assembly comprises other test pieces each comprising a central part having a shape and dimension corresponding to one of the complex shapes of the first portions of the aeronautical part.

[0022] According to one embodiment, the central portion comprises the same roughness Ra as the first portion. By same roughness is meant a value Ra of the central portion equal to + or - 5% of the roughness value Ra of the first portion.

[0023] According to one embodiment, the first portion of the aeronautical part comprises a wall with a thickness less than a value equal to five times a roughness Ra of one of the surfaces of the first portion. This thickness to roughness ratio implies a difficulty in calculation by finite element. Thus the test piece makes it possible to facilitate the determination of the service life at a lower cost. According to one embodiment, the first portion of the aeronautical part comprises an undercut wall partially closing an internal volume formed by the part of the first portion and in that the part comprises a wall having a thickness less than 1 mm. This low thickness as well as the difficulty in surface control of the first portion defining the internal volume lead to a difficulty in calculation by finite element while the test piece makes it possible to facilitate the determination of the service life at a lower cost.

[0024] According to one embodiment, the part of the first portion of the aeronautical part comprises an internal raw surface comprising a first internal face and a second internal face facing the first internal face and in that the central portion of the test piece comprises an internal raw surface corresponding to the internal raw surface of the first portion. The fact that the internal raw surface comprises two internal faces facing each other implies a complex shape. Indeed, for example, the shape is U-shaped. According to one example, the distance between the two faces is less than 3 mm. Such a distance prevents a measurement and therefore complicates a finite element calculation.

[0025] According to one embodiment, the first portion of the aeronautical part comprises a machined external surface comprising traces of striations, in that the central portion of the test piece comprises a machined external surface corresponding to that of the first portion comprising traces of striations oriented in the same direction. This makes it possible to have the same characteristics of an aeronautical part further comprising machining tolerances increasing the tolerance dimension chain.

[0026] According to one embodiment, the central portion and the first portion of the aeronautical part comprise a metal-based composite.

[0027] A second aspect of the invention relates to a method of manufacturing the assembly according to the first aspect of the invention (with or without the different characteristics of the different embodiments), in which the additive manufacturing is carried out by a laser powder bed fusion process, the aeronautical part and the test piece having the same manufacturing tolerances and were produced by the same characteristics of the following additive manufacturing: • manufacturing direction, • laser parameters including at least the same power, vector deviation, movement speed.

[0028] The fact of producing the test piece in an identical manner makes it possible to increase the precision of the tests and therefore of the measurement parameters.

[0029] According to one example, the method comprises a step of machining a surface of the first portion and a step of machining a surface of the central portion corresponding to that of the surface of the first portion, the two machining steps having the same orientation forming machining striations on the surfaces according to the same orientation.

[0030] A third aspect of the invention relates to a method for estimating the characteristic of a portion of an aeronautical part of the assembly according to the first aspect of the invention comprising: • a step of manufacturing the test piece of the assembly in a manner identical to the manufacturing of the first portion of the aeronautical part, • a step of fixing the heads of the test piece to a mechanical or thermomechanical testing machine, • a step of mechanical or thermomechanical testing of the test piece by the machine, • a step of recovering characterization data obtained by machine measurements during the test.

[0031] A fourth aspect of the invention relates to a method for estimating the lifespan of the aeronautical part of the assembly according to the first aspect of the invention (with or without the different characteristics of the different embodiments), comprising: • a step of manufacturing the test piece of the assembly in a manner identical to the manufacturing of the first portion of the aeronautical part, • a step of fixing the heads of the test piece to a mechanical or thermomechanical testing machine, • a step of mechanical or thermomechanical testing of the test piece by the machine, • a step of recovering test result data obtained by machine measurements, • a step of calculating a lifetime of the first portion from the result data, • a step of calculating the life of the part from the calculation of a lifetime of the first portion and lifetimes of other second portions of the part calculated by finite elements.

[0032] The aeronautical part in fact comprises second portions having shapes different from those of the first portion, and the method further comprises the steps of: • finite element calculation of the lifetime of the second portions, • the step of calculating a part's lifetime being the lifetime value the smallest among those calculated for at least one first portion and the second portions. • According to one embodiment, the service life estimation method further comprises the step of manufacturing several test pieces in a manner identical to the manufacturing of the first portion of the aeronautical part, each test piece being manufactured by a different machine manufacturing aeronautical parts having first portions of shape and dimension identical to that of the first portion of the aeronautical part of the assembly and • in that the steps of: fixing, mechanical or thermomechanical testing of the test piece and data recovery are carried out on each test piece and preferably by the same machine, this allows better characterization of the dispersion resulting from the production process, the test pieces were manufactured on several machines to understand the mechanical dispersion resulting from these parametric variations.

[0033] this allows better characterization of the dispersion resulting from the production process, the test pieces were manufactured according to several batches of powder to understand the mechanical dispersion resulting from these parametric variations.

[0034] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0035] The figures are presented for information purposes only and in no way limit the invention.

[0036] [Fig. 1] is a schematic representation of a machine conventionally used for implementing a laser powder bed fusion process.

[0037] [Fig.2A] is a schematic representation of a portion of an aeronautical part formed by the machine of [Fig.l] comprising a portion of this portion having a complex shape and / or dimension.

[0038] [Fig.2B] is an enlargement of the portion of the aeronautical part shown in [Fig.2A].

[0039] [Fig.3] is a schematic representation of a thickness at the portion of the aeronautical part represented in [Fig.2B].

[0040] [Fig.4] is a schematic representation of a test piece comprising a complex shape identical to that of the portion of [Fig.2B]. DETAILED DESCRIPTION

[0041] The figures are presented for information purposes only and in no way limit the invention.

[0042] A first aspect of the invention relates to an assembly comprising on the one hand a aeronautical part 10, an example of which is partially shown in [Fig.2A], comprising a first portion 100 having a part 100a, the example of which is shown in FIGS. 2A and 2B, composed of a material resulting from additive manufacturing from a powder, and on the other hand a test piece 3, an example of which is shown in [Fig.4], composed of a material identical to the material of the first portion 100 of the aeronautical part 10. The test piece 3 comprises two fixing heads 31 and a central portion 30 extending between the two fixing heads 31, the central portion 30 and the part 100a being of identical shape and dimension.

[0043] [Fig. 1] shows a schematic representation of an example of a machine 2 for additive manufacturing from a powder, in this case a 3D printer used for the production of at least the first portion of the aeronautical part 10 (this may be all or part of the aeronautical part) and of the test piece 3, by laser fusion on a powder bed 7. The machine 2 comprises: • a manufacturing tank 4 comprising a manufacturing plate 42 forming a base for the manufacturing of the portion 100 of the part 10 and of the test piece 3, the manufacturing plate 42 being movable in translation along a deposition axis Z, • a feed tray 5 for powder 7 arranged near the manufacturing tray 4 and comprising a bottom 52 movable in translation along the Z axis, • a scraper 6 movable in translation along a Y axis, perpendicular to the Z axis, on a first rail 22 of the machine 2, and • at least one laser 8 comprising a laser beam 82, the laser 8 being movable in translation along an X axis, perpendicular to the Z axis, and along the Y axis, on a second rail 24 of the machine 2.

[0044] The additive manufacturing of the portion 100 of the part 10 and of the test piece 3 requires the prior creation of a digital production file via suitable software comprising: • a division of the 3D model of the part into a plurality of slices having a predetermined thickness, and • the manufacturing direction, • the parameters of the laser 8 such as its power, movement speed, the vector deviation (the scanning pattern of the laser beam 82), the thickness of the slices of the portion of the aeronautical part 10 etc.

[0045] These laser parameters are identical for manufacturing the test piece or the portion of the part.

[0046] The method for manufacturing an aeronautical part 10 and the test piece 3 by laser fusion on a powder bed comprises the following successive steps: • translation of the bottom 52 of the feed tray 5 along the Z axis, upwards, so as to obtain a raised quantity of powder 7, • translation of the bottom 42 of the manufacturing tank 4 along the Z axis, downwards, so as to obtain a free space above the powder bed 7 present in the manufacturing tank 4, • transfer by the scraper 6 of a quantity of powder 7 from the feed tank 5 to the manufacturing tank 4 and distribution of the powder 7 uniformly in the manufacturing tank 4 so as to create a new layer of powder 7 whose thickness is substantially equal to that of a slice of the part 10, • selective scanning by the laser beam 82 of the laser 8 of certain areas of the newly deposited powder layer 7 so as to fuse and solidify the powder particles to create a two-dimensional slice of the part 10, and • repeating the three previous steps until obtaining the final three-dimensional part 10.

[0047] Such a machine 2 and such a method make it possible to produce parts or portions of parts (adding a layer to an existing part) such as that shown in radial section in [Fig.2A] corresponding to a distributor of a turbomachine of an aircraft.

[0048] In this example, the part 10 comprises at least a first portion 100 surrounded by a frame in [Fig.2A], represented by an enlargement in [Fig.2B]. The first portion 100 comprises a part 100a surrounded in [Fig.2B]. The first portion 100 is a part of revolution around an axis X, comprising a wall 101 of revolution around the axis X, having the part 100a of this first portion 100 surrounded in [Fig.2B].

[0049] The first portion 100 comprises in this case an undercut wall 102 extending from the wall 101 towards another wall 103 extending from the wall 101 partially closing (there remains a clearance between the undercut wall 102 and the wall 103) an internal volume formed by the part 100a of the first portion 100. This part 100a is very difficult or even impossible to manufacture by machining or molding, and is therefore produced by an additive manufacturing process from powder, for example by the machine 2. The internal volume therefore also has a shape of revolution.

[0050] The wall 101 of the part 100a comprises a smooth external surface 100e, in this case machined but could be polished. The wall 101 of the part 100a comprises an internal surface 100i delimiting the internal volume. Given that this internal volume is very difficult to access, this internal surface 100i is rough, that is to say not machined, not polished. It is the roughness of this internal surface 100i relative to the thickness of this wall measured between the internal surface 100i and the external surface 100e which makes this part complex. In this case, the shape is a U-shape which a priori is not complex but the thickness of the wall between the internal surface 100i and external surface 100e has a variability of more than 10% making the part 100a complex.

[0051] [Fig.3] represents an enlargement of a section at the level of an area of ​​the part 100a of the wall 101. This wall 101 comprises in this area a small thickness measured between the internal surface 100i and the external surface 100e. Here, due to the manufacturing tolerances and in particular the internal surface 100i which is therefore a rough surface having a roughness Ra, here of 150 pm, the thickness of the wall 101 is between an average maximum thickness Emax and an average minimum thickness Emin whose difference is greater than + or - 10%. In this example, it can be seen that the average maximum thickness is approximately 740 pm and the average minimum thickness is approximately 600 pm. This area of ​​the wall 101 thus comprises an average thickness of 670 pm having a high tolerance + or - 70 pm due to the roughness Ra of the raw internal surface.The thickness tolerance in this area is therefore + or - 10% (i.e. a variability of 20%) the average thickness leading to too much variability to calculate a lifetime per finished element. As can be seen from the side of the external surface 100e is a machined (or polished) surface and includes traces of striations from machining.

[0052] Thus, to characterize the mechanical part, in particular the first portion, the example of this first aspect of the invention concerns the assembly according to this example further comprising the aeronautical part 10, the test piece 3 shown in [Fig.4], comprising a central portion 30 having the same shape and the same dimensions and manufactured with the same powder composition as the part 100a. The test piece 3 further comprises two fixing heads 31 on either side of the central portion. The heads 31 of the test piece make it possible to test it on a conventional fatigue machine.

[0053] A second aspect of the invention relates to a method for manufacturing an assembly according to the first aspect of the invention in which the additive manufacturing is carried out by a powder bed laser fusion method, for example that described in relation to [Fig.l]. The aeronautical part 10 and the test piece 3 have the same manufacturing tolerances and were produced by the same following additive manufacturing characteristics:

[0054]

[0055]

[0056]

[0057] • manufacturing direction, • laser parameters including at least the same power, vector deviation, movement speed. The manufacturing method may comprise a step of machining a surface of the first portion 100 and a step of machining a surface of the central portion corresponding to that of the surface of the first portion, the two machining steps having the same orientation forming machining striations in the same orientation. A third aspect of the invention relates to a method for estimating the characteristic of a portion of an aeronautical part, such as the aeronautical part 10, of the assembly according to the first aspect of the invention comprising a step of manufacturing the test piece of the assembly in a manner identical to the manufacturing of the first portion (100) of the aeronautical part, • a step of fixing the heads of the test piece to a mechanical or thermomechanical testing machine, • a step of mechanical or thermomechanical testing of the test piece by the machine, • a step of retrieving test result data obtained by machine measurements. A fourth aspect of the invention relates to a method for estimating the lifespan of an aeronautical part, such as the aeronautical part 10 of the previous example, of the assembly according to the first aspect of the invention. The method for estimating the lifespan of the aeronautical part 10 comprises: • a step of manufacturing the test piece 3 of the assembly in a manner identical to the manufacturing of the first portion 100 of the aeronautical part 10, • a step of fixing the heads 31 of the test piece 3 to a mechanical or thermomechanical testing machine, • a mechanical or thermomechanical testing step of the test piece 3 by the testing machine, • a step of recovering test result data obtained by measurements from the test machine, • a step of calculating a lifetime of the first portion 100 from the result data, • a step of calculating a lifetime of the part 10 from the calculation of a lifetime of the first portion 100 and lifetimes of other second portions of the part 10 calculated by finite elements.

[0058] According to one example, the lifetime estimation method further comprises the steps of: • manufacturing several test pieces 3 in an identical manner to the manufacturing of the first portion 100 of the aeronautical part 10, each test piece 3 being manufactured by an additive manufacturing machine from a powder, different manufacturer of the aeronautical parts having first portions of shape and dimension identical to that of the first portion 100 of the aeronautical part 10 of the assembly and • in that the steps of: fixing, mechanical or thermomechanical testing of the test piece and data recovery are carried out on each test piece and preferably by the same testing machine.

[0059] According to another example, which can be combined with the previous example, the lifetime estimation method further comprises the steps of: • manufacturing several test pieces 3 in an identical manner to the manufacturing of the first portion 100 of the aeronautical part 10, each test piece 3 being manufactured using additive manufacturing from a powder from different batches of powder and in that the steps of: fixing, mechanical or thermomechanical testing of the test piece 3 and data recovery are carried out on each test piece 3 and preferably by the same machine.

[0060] In these two examples, the step of calculating a lifetime of the first portion 100 is carried out from the result data obtained by the machine on each sample 3.

[0061] The steps of calculation and data recovery are carried out using a computer.

[0062] Of course, in the case where the part 10 comprises other first portions each comprising another part 100a' called "complex", such as that circled in [Fig.l], the methods and the assembly may comprise a manufacture of one or more other test pieces 3 each comprising a central part of shape and dimension identical to the shape and dimension of a corresponding part 100a' of one of the other first portions of the aeronautical part. In this case the complex part 100a' is complex in its shape, in fact it comprises a wall forming a closed internal volume with internal walls in this closed volume, manufacturable only by additive manufacturing from a powder.

[0063] In order to further characterize the dispersion resulting from the production process, the test pieces were manufactured on several machines and with several batches of powder to understand the mechanical dispersion resulting from these parametric variations.

[0064] Unless otherwise specified, the same element appearing in different figures has a single reference.

Claims

Claims

1. Assembly comprising: - an aeronautical part (10) comprising a first portion (100) composed of a material resulting from additive manufacturing from a powder, - a test piece (3) composed of a material identical to the material of the first portion (100) of the aeronautical part (10), the test piece (3) comprising two fixing heads (31) and a central portion (30) extending between the two fixing heads (31), the central portion (30) being of shape and dimension identical to the shape and dimension of a part (100a) of the first portion (100) of the aeronautical part.

2. Assembly according to the preceding claim in which the central portion comprises the same roughness as the first portion (100).

3. Assembly according to one of the preceding claims in which the first portion (100) of the aeronautical part (10) comprises a wall comprising a thickness less than a value equal to five times a roughness Ra of one of the surfaces of the first portion (100).

4. Assembly according to one of the preceding claims in which the first portion (100) of the aeronautical part (10) comprises an undercut wall (102) partially closing an internal volume formed by the part (100a) of the first portion (100) and in that the part (100a) comprises a wall having a thickness of less than 1 mm.

5. Assembly according to any one of the preceding claims in which the part (101a) of the first portion (100) of the aeronautical part (10) comprises an internal raw surface (lOli) comprising a first internal face and a second internal face facing the first internal face and in that the central portion (30) of the test piece (3) comprises an internal raw surface (30i) corresponding to the internal raw surface (lOli) of the first portion (100).

6. Assembly according to any one of the preceding claims in which the first portion (100) of the aeronautical part (10) comprises a machined external surface (100e) comprising traces of striations, in that the central portion (30) of the test piece comprises a machined external surface corresponding to that of the first portion (100) comprising traces of striations oriented in the same direction.

7. Assembly according to the preceding claim in which the central portion and the first portion of the aeronautical part comprise a metal-based composite.

8. Method of manufacturing the assembly according to any one of the preceding claims in which the additive manufacturing is carried out by a powder bed laser fusion process, the aeronautical part (10) and the test piece (3) having the same manufacturing tolerances and having been produced by the same following additive manufacturing characteristics: - manufacturing direction, - laser parameters including at least the same power, vector deviation, displacement speed.

9. Method for estimating the lifespan of the aeronautical part (10) of the assembly according to one of the preceding claims 1 to 6, comprising: - a step of manufacturing the test piece (3) of the assembly in a manner identical to the manufacturing of the first portion (100) of the aeronautical part (10), - a step of fixing the heads (31) of the test piece (3) to a mechanical or thermomechanical testing machine, - a step of mechanical or thermomechanical testing of the test piece (3) by the machine, - a step of recovering test result data obtained by measurements of the machine, - a step of calculating a lifespan of the first portion (100) from the result data, - a step of calculating a lifespan of the part from the calculation of a lifespan of the first portion (100) and lifespans of other second portions of the part calculated by elements finished.

10. A method of estimating lifetime according to the preceding claim, further comprising the steps of: of manufacturing several test pieces (3) in an identical manner to the manufacture of the first portion (100) of the aeronautical part (10), each test piece (3) being manufactured by a different machine manufacturing aeronautical parts (10) having first portions of shape and dimension identical to that of the first portion (100) of the aeronautical part (10) of the assembly (3) and • in that the steps of: fixing, mechanical or thermomechanical testing of the test piece (3) and data recovery are carried out on each test piece (3) and preferably by the same machine.

11. A method for estimating a lifespan according to claim 9 or 10, further comprising the step of manufacturing several test pieces (3) in an identical manner to the manufacturing of the first portion (100) of the aeronautical part (10), each test piece (3) being manufactured using additive manufacturing from a powder from different batches of powder, and in that the steps of: fixing, mechanical or thermomechanical testing of the test piece (3) and data recovery are carried out on each test piece (3) and preferably by the same machine.

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