Draft of a part produced by additive manufacturing and production process

Abstract

TITLE: Rough of a part produced by additive manufacturing and method of obtaining it The invention relates to a rough (10) of a part (1) comprising a first lateral wall (11) from which extends a supported portion (13), the rough (10) being produced by additive manufacturing comprising the melting and solidification of successive layers of powder, the rough (10) comprising a support (3) intended to support the supported portion (13) during its manufacture, the support (3) extending under the supported portion (13) and comprising a plurality of lamellae (31) extending side by side, each lamella (31) extending along the manufacturing direction V from an internal end (311) connected to the supported portion (13) and forming a breakable zone, to an external end (312), the support (3) being configured to be removed from the part (1),Each of the lamellae (31) is configured to be broken at least at the level of said breakable zone by application of a force at its outer end (312) and in a direction transverse to a direction of elongation of the lamella (31). Figure 2,

Description

Title of the invention: Rough draft of a part produced by additive manufacturing and method of obtaining it. Technical field

[0001] The field of this disclosure is that of additive manufacturing, more specifically of powder bed fusion laser manufacturing. Previous technique

[0002] A number of processes for shaping parts, which may be metallic or composed of a polymer, are known in the prior art. Some of these processes differ from so-called "conventional" methods involving material removal, such as machining. Such processes consist of the selective consolidation of powder layers to build up, layer by layer, a three-dimensional object.

[0003] More specifically, such a selective melting process can be described as follows: first, a digital production file is created using suitable software. This instruction file is typically generated by slicing the CAD model of an object into layers, generally of a given thickness. The production file includes all the instructions necessary to execute the process: in particular, the laser paths required to produce the object, layer by layer.

[0004] The equipment for implementing the process may include a build platform that serves as the base for manufacturing the object. A powder spreading device allows a layer of powder of the desired material to be spread onto the build platform, to a desired thickness. This device may be a roller or a scraper that moves in translation along an axis on either side of the powder bed.

[0005] Once the powder layer is deposited, one or more lasers selectively scan certain areas of the powder bed, corresponding to a slice of the object to be produced, according to the instruction file created beforehand. Indeed, the scanning pattern, as well as all the parameters of this laser scanning (such as the laser power, the scanning speed, the spacing between two laser passes, etc.), can be dictated to the equipment by the instruction file. The laser's passage over the powder bed raises the powder to a temperature above its melting point. A molten pool is thus created. It can also be provided that another heat source preheats the powder bed to a temperature slightly below its melting point, to accelerate the laser scanning. Upon cooling, at least to a temperature below its melting point, this pool solidifies and forms A solid metal cord defines a "slice" of the object to be created. Following the laser scanning of a layer of powder, a 2D section of the desired object is thus obtained.

[0006] The powder spreading device then deposits a new layer of powder on top of the previous one. A new laser scan is performed to consolidate a new "slice" of the object.

[0007] Thus, iteratively, a 3-dimensional object is reconstituted by successive consolidation of 2-dimensional sections, or slices, one on top of the other.

[0008] Only a certain amount of powder is solidified by the laser as the process progresses, so the object is "embedded" in the remaining powder. This technique can therefore have the advantage of using the powder as a support for the creation of successive layers of the part, unlike, for example, the rapid prototyping process by fused deposition modeling (FDM), which requires specific supports for the overhanging parts of the part.

[0009] However, with regard to the production of metal parts by powder bed fusion, it may be necessary to create supports to enable the feasibility of the part. In particular, such supports are useful for parts of the part where a large portion does not rest on the build platform or on a previous layer. This is especially the case for portions of the part that extend between two other portions of the part, or that protrude from a wall, thus creating a cantilever.

[0010] These supports can also act as thermal bridges, connecting the part to the build platform. After such a rough part is produced, the supports are removed during a removal operation and then possibly adjusted before assembly of the resulting part. The supported portion, of course, is not intended to be removed.

[0011] Such a removal operation generally involves the use of a tool, for example a chisel, robotic or manual, allowing a local force to be applied to break the support in order to separate it from the part.

[0012] This removal operation is not always easy to perform. Indeed, in some cases, the supported portion, the manufacture of which requires the creation of such a support, may extend into a confined volume that hinders access for the tool and makes the removal operation difficult or even impossible. This part shape can be found for all types of parts, for example, for structural parts or for aerodynamic or hydrodynamic parts.

[0013] Such difficulties are encountered particularly on bladed parts, for example, where the blades, which can be supported, extend between two inner and outer ferrules (meridians), or where the blades extend from a The single ferrule is too close together to allow easy access to the support.

[0014] An important challenge is to be able to remove the support without damaging the supported surface, which in some cases may play a functional role and have precise nominal dimensions. This is particularly true for aerodynamic parts, whose supported surface may contribute to the flow of a fluid.

[0015] The purpose of this disclosure is therefore to mitigate at least in part the disadvantages of the prior art mentioned above. Summary

[0016] The objectives mentioned above are achieved in particular by a rough part comprising a first lateral wall from which a supported portion projects, the rough part being produced by additive manufacturing comprising the melting and solidification of successive layers of powder along a vertical manufacturing direction V, the rough part comprising a support intended to support the supported portion during its manufacture, the support extending under the supported portion and comprising a plurality of lamellae extending side by side, each lamella extending along the manufacturing direction V from an internal end connected to the supported portion and forming a breakable zone at said internal end, to an external end, the support being configured to be removed from the part,Each of the lamellae is configured to be broken at least at the level of said breakable zone by applying a force at its outer end and in a direction transverse to a direction of elongation of the lamella.

[0017] Thus, although the part typically has a shape which should make removal of the support difficult, or even impossible, the part blank according to the present disclosure has a support which is particularly easy to remove.

[0018] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other:

[0019] According to an improvement, the lamellae extend substantially parallel to each other along their elongation direction. Thus, advantageously, all the lamellae can be removed by applying a force in a single direction.

[0020] According to an improvement, the blank includes a second side wall, the supported portion extending from the first side wall to the second side wall, and the support includes the plurality of slats extending under the supported portion and between the first side wall and the second side wall.

[0021] According to an improvement, the blank is the blank of an annular aerodynamic or hydrodynamic part, in which: - the supported portion is a blade of the aerodynamic or hydrodynamic part comprising a leading edge and a trailing edge, - the first lateral wall is an internal or external ferrule, the support slats each extending lengthwise from the vicinity of the leading edge to the vicinity of the trailing edge, forming a curve extending parallel to the first lateral wall.

[0022] Such an improvement, in which the slats extend according to the curvature of the ferrules, allows any imperfections arising from the breakage of the slats and remaining on the supported surface of the blades to be oriented in the direction of the aerodynamic flow lines of the part, from the leading edge to the trailing edge of the supported portion, and do not interfere with the flow of the fluid on the blade.

[0023] According to an improvement, the second lateral wall is an external ferrule of the annular aerodynamic or hydrodynamic part. In this case, the blades can extend substantially radially from the inner ferrule to the outer ferrule.

[0024] According to an improvement, the support comprises N successive lamellae extending along an elongation direction, the free outer end of a k-th lamella among N lamellae comprising at least one notch positioned opposite, along the direction transverse to the elongation direction of the lamellae, a solid portion of a (k+l)-th lamella.

[0025] Such notches allow the formation of passages traversing transversely through the slat, intended to provide physical access to the second slat adjacent to the first slat. In this way, it is easier to apply a transverse force to detach the second slat from the workpiece.

[0026] According to an improvement, a notch in a (kl)th lamella is provided, on a first side of a solid portion of a kth lamella, opposite in the direction transverse to the direction of elongation of the lamellae, a notch in a (k+l)th lamella, on a second side of said solid portion of the kth lamella opposite to the first side.

[0027] Such a "checkerboard" or "quincunx" arrangement allows transverse breaking forces to be applied at various longitudinal positions on the second slat, which makes it possible to guarantee a uniform break, exclusively localized at the level of its internal end.

[0028] According to an improvement, at least one notch extends vertically so as to open onto the outer end of the slat over a height of between 1 and 50mm.

[0029] Thus, depending on the height of the notch, it is possible to adapt to different slat heights, and / or to apply a transverse breaking force at a height intermediate, under the outer end of the slat, so as to generate less bending of the latter.

[0030] According to an improvement, each lamella is separated from adjacent lamellae by a distance of between 0.1mm and 5mm.

[0031] In this way, the supported portion is effectively supported and the shape of the nominal surface of the part is controlled.

[0032] According to an improvement, one or more of the lamellae comprise a chamfer at their outer end.

[0033] Such chamfers allow for easier removal of the unsolidified powder, advantageously after the manufacture of the part and before the support removal operation.

[0034] Furthermore, this disclosure relates to a method for obtaining a part from a blank of a part as described above, the method comprising: - Manufacturing of the rough part including the support, by additive manufacturing including the melting and solidification of successive layers of powder.

[0035] According to an improvement of the method, the lamellae extend longitudinally, and the method includes breaking the lamellae of the support by applying a force in a direction transverse to the direction of elongation of the lamellae. Brief description of the drawings

[0036] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0037] [Fig. 1] shows a schematic representation of an installation for implementing an additive manufacturing process and for producing a rough part according to an example in this disclosure,

[0038] [Fig.2] shows a perspective view of a rough part according to the example in [Fig.1], which has been turned over to reveal strips of the support according to an example,

[0039] [Fig.3A],

[0040] [Fig.3B],

[0041] [Fig.3C] each show a schematic representation viewed from below of several examples varying in particular the orientation of the lamellae as well as the shapes of the side walls,

[0042] [Fig.4] shows a schematic representation of an aerodynamic part according to a particular application of the present disclosure,

[0043] [Fig.5] shows a schematic representation of the aerodynamic part of [Fig.4] seen from below,

[0044] [Fig. 6A] shows a schematic representation of a supported portion (here, a blade) of the aerodynamic part, viewed from below, without support,

[0045] [Fig. 6B] shows a schematic representation of the supported portion of [Fig. 6A], viewed from below, with a support comprising slats extending parallel to the side walls, according to one example,

[0046] [Fig.7] shows a schematic representation of a vertical and longitudinal cross-sectional view of a blade of the aerodynamic part of [Fig.4], the cutting plane being located between the two inner and outer ferrules, and on which the support is visible under the blade, according to an example,

[0047] [Fig.8] shows a schematic representation of a vertical and transverse cross-sectional view of a blade of the aerodynamic part of [Fig.4], on which a plurality of blades, cut transversely, are seen, and including a detailed view of an example of a breakable area,

[0048] [Fig.9] shows a schematic representation of an improvement according to an example in which the support slats have notches; an example of a particular notch distribution pattern is shown,

[0049] [Fig. 10] shows a more detailed schematic side view representation of a first slat comprising notches and a second slat, according to a particular example,

[0050] [Fig. 11] shows a schematic representation of a support comprising lamellae each comprising two chamfers, on either side of their external end, according to a particular example.

[0051] [Fig. 12] shows a schematic representation of a part having a single lateral wall, in this case an internal ferrule, from which extend supported portions, constituted according to this example, by blades. Description of the implementation methods

[0052] The drawings and description below contain, essentially, elements of a definite nature. They may therefore not only serve to better understand this disclosure, but also contribute to its definition, if necessary.

[0053] In the various figures, the same reference numerals designate identical or similar elements. For the sake of brevity, only the elements that are useful for understanding the described embodiment are shown in the figures and are described in detail below.

[0054] In the following description, when referring to absolute positional qualifiers, such as the terms "front", "back", "top", "bottom", "left", " "Right," etc., or relative terms such as "above," "below," "superior," "inferior," etc., or orientation qualifiers such as "horizontal," "vertical," etc., refers, unless otherwise specified, to the orientation of the figures. Furthermore, the term "approximately" is to be interpreted as indicating that the result obtained includes a margin of error of + / - 10%, unless otherwise stated.

[0055] Reference is now made to [Fig. 1], which shows a rough draft 10 of a part 1, obtained by an additive manufacturing process comprising the melting and local solidification of successive layers of powder. The installation for implementing this manufacturing process may include, in particular, a tank 2 filled with powder 21 and may also include a build platform 22 moving along a vertical build direction V. Typically, at each solidification of a layer of powder, the platform 22 lowers along this build direction V so that a new, as yet unsolidified, layer of powder is deposited on top of the previous one.

[0056] For example, melting can be achieved by scanning a laser beam that can be configured to locally heat the powder and thus "draw" the outline of the "slice" of the blank to be produced. Solidification occurs through cooling, for example, by allowing the temperature to fall below the powder's melting point after the laser has passed. Means for accelerating this cooling can also be provided.

[0057] According to this disclosure, the part 1 whose roughing is being made has a particular shape. Indeed, it has at least one first lateral wall 11, from which a so-called "supported" portion 13 extends. The supported portion 13 therefore requires the presence of a support 3 for its manufacture.

[0058] According to a particular example in this disclosure, the part 1 whose roughing is being carried out has another particular shape. Indeed, in this case, the part 1 has two lateral walls 11, 12, joined to each other by a supported portion 13. The lateral walls 11, 12 and the supported portion 13 then form a difficult-to-access volume in which a support 3 is formed, allowing the solidification of the powder that forms the supported portion 13.

[0059] According to one example, such a volume is difficult to access, particularly when the first side wall 11 and the second side wall 12 extend at least partially opposite each other. The first and second side walls 11, 12, as well as the supported portion 13, then form three U-shaped sides, and the support 3, included in this volume and bordered by the three sides, is difficult to remove.

[0060] Reference is now made to [Fig. 2], which shows an example of a part blank 10 according to this disclosure. It will be noted that the part blank shown in [Fig.2] is similar to that of [Fig.1], but it is reversed so that the vertical manufacturing direction is oriented downwards on [Fig.2].

[0061] Such a part blank 10 comprises a part 1 and a support 3 that enables the manufacturability of the supported portion 13. Indeed, the support 3 supports the supported portion 13 during its manufacture. Such a support typically extends from the manufacturing platform 22 to a lower surface of the supported portion 13. It can also extend from another part of the already manufactured part blank to the lower surface of the supported portion 13. The supported portion 13 is thus stabilized during the melting and solidification process of the powder layers that constitute it.

[0062] To facilitate the removal of the support 3 by manual or robotic adjustment, the support 3 comprises several individually breakable slats 31 extending side by side, each slat 31 having a sufficiently small contact surface with the workpiece 1. To this end, the slats may have a relatively small thickness, for example between 1 and 15 mm, so that their inner end 311 is easily breakable. However, to effectively perform their function of supporting the supported portion 13, the slats 31 extend very close to each other. In fact, they extend at a distance from each other so as to form a gap 32 to allow the passage of a tool 4 between the slats 31 and to exert a force substantially perpendicular, or transverse, to their direction of elongation to detach them from the workpiece 1.

[0063] Here, "along a substantially perpendicular direction" means that the applied force includes at least one component along a transverse direction T to the longitudinal elongation direction L of the slat 31 considered at the point of application of the force. In particular, when the slat 31 extends lengthwise in a curved manner, the applied force includes at least one component normal to a tangent to the elongation direction of the slat 31 at the point of application of the force.

[0064] Such an effort can be made manually by an operator, particularly using a tool, or it can be made by an automated solution. Such a tool could, for example, be a chisel, or a clamp capable of gripping each slat or group of slats to apply transverse stress. Typically, the force applied at the outer end 312 of a slat induces, through the lever arm formed by the height of the slat 31, a moment at its inner end 311 which causes it to break at the breakable area. To this end, the slat 31 can be dimensioned in width so as to be neither too flexible nor too rigid.

[0065] The dimensions of the slats may also depend on the material used to manufacture the blank part. Typically, the slats 31 of the support 3 may be made of the same material as the part 1. According to other examples, it is possible that the support is made of another material. In particular, the material of the slats 31 and of part 1 is a metallic material.

[0066] Generally, we consider directions L and T, corresponding to the longitudinal and transverse directions at a point of each slat 31, both extending in a plane normal to the vertical direction V. If the slat extends lengthwise along one or more curves, the direction L corresponds to the direction of the tangent to said slat 31 at a particular point, and the direction T corresponds to its perpendicular, in the plane normal to the vertical V. Thus, in the present text, when reference is made to the longitudinal and transverse directions, these directions are to be interpreted at a particular point of the slat 31 in question.

[0067] Typically, each slat extends along the vertical direction V, to a certain height from an inner end 311 attached to the workpiece and a free outer end 312, and extends lengthwise along an elongation direction from a first edge 30.1 of the support to a second edge 30.2 of the support opposite the first edge 30.1. Each slat also has a width, measured transversely to its elongation direction. Generally, the width dimension of a slat 31 is less than its length dimension along the elongation direction.

[0068] According to examples, the lamellae can be of different shapes, lengths and widths (in other words, "thickness") from each other.

[0069] The outer end 312 is said to be "free" because the workpiece blank 10, before the removal of the support 3, is removed from the manufacturing platform 22 in contact with which it can be manufactured.

[0070] It is possible that, from the first edge 30.1 to the second edge 30.2 of the support 3, each slat 31 defines one or more curves. According to examples, the slats 31 extend lengthwise parallel to each other.

[0071] Generally, the strips 31 are such that when a cut is made along a plane perpendicular to the manufacturing direction V at an intermediate height of the strips 31, an observer sees a succession of solid bands (corresponding to the cut strips) and gaps 32 between the solid bands. Advantageously, the gaps 32 are narrower than the width of the strips 31. For example, the gaps 32 may have a width DI of between 0.1 and 5 mm, while the strips 31 may have a width of between 1 and 15 mm.

[0072] The height of the cut is said to be "intermediate" in that it is made between the inner end 311 and the outer end 312 of the lamellae 31.

[0073] In particular, when such a cut is made, the side walls 11, 12 and the support 3 are such that the succession of solid bands and gaps 32 are contained between the two side walls 11, 12.

[0074] Generally, the height of a slat is defined according to the vertical direction V, and with reference to the distance from a manufacturing platform 22, or in other words, from the outer end 312 of the slat 31. According to examples, each slat has, over at least a portion of its height, a portion which is solid over the entire length of the slat 31 from a first edge 30.1 of the support to a second edge 30.2 of the support 3.

[0075] Each of the lamellae 31 comprises an inner end 311 connected to the supported portion 13 and forming a breakable zone, and a free outer end 312. Typically, the two inner and outer ends 311, 312 of each lamella are separated from each other along at least one vertical component in the manufacturing direction V.

[0076] The support 3 is configured to be removed from the part and, for this purpose, each of the slat 31 is configured to be broken at least at the level of the breakable area by applying a force at the level of its free end 312 and in a direction substantially perpendicular to the extent of the slat 31.

[0077] The breakable zone can advantageously be designed to exhibit localized weakness at the inner end of the lamella 31. This means, in particular, that it can be intentionally weakened relative to the rest of the lamella 31. This localized weakness can be achieved through specific design techniques, such as the introduction of recesses, thickness reductions, or modifications to the material density at this precise location. Furthermore, simply presenting angles, rounded or otherwise, at the junction with the supported portion 13, where stress concentration occurs, may be sufficient to create a breakable zone.

[0078] Typically, the breakable area can extend continuously over the entire length of the slat 31, from the first edge 30.1 to the second end edge 30.2 of the support 3.

[0079] One advantage of this design is that it facilitates the removal process of the support 3 after the fabrication of the workpiece blank 10. When a force is applied at the free outer end 312 of the slat 31, the breakable area breaks easily, thus allowing the support to be detached, for example slat by slat, limiting damage to the supported portion 13 of the workpiece 1. This simplifies post-processing and reduces the risk of deformation or deterioration of the nominal surface of the supported portion 13.

[0080] Furthermore, this localized fragility allows for precise control of the fracture site, thus ensuring a clean and precise separation between the support 3 and the part 1. This can be of particular interest in applications where the precision and nominal surface quality of the part 1 are crucial, as may be the case with aerodynamic components. Indeed, the presence of such a breakable zone makes it possible to limit the risks that a slat 31 may break at an intermediate height between the end

[0081] Figure 3 gives three examples of particular arrangements of the lamellae and the side walls. Of course, other configurations are possible without departing from the scope of this disclosure. In particular, in an example not shown, the lamellae 31 may extend obliquely with respect to the side walls 11, 12, or the lamellae may not extend lengthwise parallel to each other.

[0082] In particular examples, notably represented in figures 3A and 3B, the lamellae can extend parallel to the lateral walls 11, 12 or substantially perpendicular to them.

[0083] In a particular example in which the slats 31 extend substantially perpendicularly to the side walls 11, 12, in particular as shown in [Fig. 2] or 3, each slat 31 can be separated from the side walls 11, 12, so that it does not present any other areas of failure than the breakable area formed at its inner end 311. In other words, according to examples, the slats 31 of the support 3 are connected to the part 1 only by their inner ends 311. In this way, the breaking force required to remove the support is reduced and the side walls 11, 12 do not suffer any damage during this removal.

[0084] The solution in this disclosure is of particular interest for aerodynamic or hydrodynamic components. "Aerodynamic" components are defined as those having at least one surface that "works" in cooperation with the flow of a gas, typically air or another gas, so as to guide that fluid and / or receive a force from an aerodynamic resultant induced by its flow. "Hydrodynamic" components are defined as those having at least one surface that works in cooperation with a liquid, typically water or another liquid. These components are typically bladed annular components, for example, of turbine distributors or diffusers (aerodynamic), or a pump impeller (hydrodynamic), having circumferentially distributed blades.

[0085] By way of non-limiting example, a turbine distributor is shown in [Fig.4] and 5, which may be an aerodynamic part whose rough 10 includes a support 3 with a blade 31.

[0086] In this particular case where the workpiece blank 10 is the workpiece blank 10 of a turbine distributor, the supported portion 13 can typically be a blade, and the side walls 11, 12 can typically be inner and outer ferrules. In cases where the workpiece in question is generally annular in shape, it typically comprises a plurality of blades distributed circumferentially between the two inner and outer ferrules.

[0087] Fig. 12 also shows an example of a part comprising a single side wall, in this case an inner ferrule 11, and a plurality of blades distributed circumferentially around the inner ferrule 11 and extending substantially radially from the inner ferrule to a free distal end. In this example, the support 3 (not shown) may extend under each blade, between the inner ferrule 11 and the free distal end of the blade in question.

[0088] More specifically, [Fig. 5] shows the distributor of [Fig. 4] viewed from below. In particular, the blade faces shown in the figure are said to be "downskinned," meaning that they are opposite the plate 22 during its manufacture by powder bed fusion. It is this lower face 131 that is then connected to the support 3 necessary for the manufacturing of the blades, which are connected only to the inner and outer ferrules and are not supported vertically by any other part of the component. Such a face is shown in more detail in [Fig. 6A] and [Fig. 6B]. In particular, view 6A represents the visible "downskin" face, without support, and [Fig.ôB] shows the same face with its support 3. In other words, [Fig.ôA] shows the nominal face of the blade, once the support is removed, and for example after a possible adjustment during which a major part of the imperfections resulting from the breakage of the lamellae 31 of the support 3 are removed.

[0089] In this case, the lamellae 31 can extend lengthwise along a curve, and parallel to the lateral walls 11, 12, formed by the inner and outer ferrules. Such an example is notably shown in [Fig. 3C] and in [Fig. 3B].

[0090] Such a direction of elongation of the blades 31, according to the curvature of the ferrules, allows any imperfections remaining on the lower surface 131 of the blades resulting from the rupture of the blades 31 at their inner end to be oriented in the direction of the flow lines of the part, and does not interfere with the airflow over the blade. Schematically, a principal flow direction E illustrating the direction of such flow lines on the blades is shown in [Fig. 3C] and [Fig. 6B].

[0091] Reference is now made to [Fig. 7], which shows a cross-section in a vertical plane, parallel to the manufacturing direction V, and intersecting the supported portion 13 formed by a fixed distributor vane. It can be seen in this figure that the support extends "under" the supported portion 13, and in particular under the lower surface 131, referred to as the "downskin" surface, of the supported portion 13.

[0092] Such a blade may have a leading edge 133 and a trailing edge 132, particularly visible in [Fig.7]. According to a particular example, the support 3 extends from the vicinity of the leading edge 133 to the vicinity of the trailing edge 132 of a blade.

[0093] In particular, it is possible that the slats 31 of the support 3 extend lengthwise from the vicinity of the leading edge 133 to the vicinity of the trailing edge 132. In this way, the spacings 32 between the slats 31 extend from the leading edge 133 to the trailing edge 132. In particular, the slats 31 extend lengthwise so as to follow a curve, parallel to the internal and external ferrules that form the side walls 11, 12.

[0094] Fig. 8 shows a section along another vertical plane perpendicular to the cutting plane of Fig. 7, the cutting plane being here transverse to the two lateral walls 11, 12 and in particular to the slats 31 of the support 3.

[0095] The configuration of [Fig.8] allows us to see in particular the U-shaped form formed by the two lateral walls 11, 12 and the supported portion 13. Indeed, the two lateral walls 11, 12 extend vertically and each has, at least over a portion of their height, preferably over at least 50% of their height, an internal wall opposite each other. In other words, the first side wall 11 has a first internal wall 111 which extends, at least partially, opposite a second internal wall 121 of the second side wall 12. The support 3 is thus advantageously made between the first and second internal walls 111, 121 of the side walls 11, 12, in a volume delimited by a U shape with three sides formed respectively by the first side wall 11, the supported portion 13, and the second side wall 12.

[0096] Generally, and as is the case in the particular example of [Fig. 8], it is possible for the slats 31 to extend vertically in a way that is not strictly vertical, also exhibiting a transverse component. According to the application example to an aerodynamic part, the vertical extent of the slats 31 may follow the possibly slightly frustoconical shape of the internal and external ferrules that form the side walls 11, 12.

[0097] If the support comprises N slats 31 extending side by side, a first slat 31 can be distinguished, extending first, in the vicinity of the first lateral wall 11, and a last Nth slat 31 extending last in the vicinity of the second lateral wall 12. As illustrated in the example of [Fig.8], the 1st slat 31 can extend vertically in a slightly inclined manner towards the other intermediate slats 31, and the Nth slat 31 can extend in a slightly inclined manner also towards the other slats 31, so that their respective inner end 311 is closer to each other in a transverse direction than their respective outer end 312. In such an example, the lamellae 31 which are located in the vicinity of the mid-transverse distance between the 1st and the Nth lamella 31 extend vertically in height.

[0098] A detailed view of [Fig. 8] shows an example of a breakable zone formed at the inner end of several lamellae 31. The illustrated example shows that a plurality of fins 313 can be arranged at the junction between the lamella 31 and the supported portion 13, so as to form a succession of joints and hollows exhibiting local weakness. Other examples of breakable zones are conceivable without departing from the scope of this disclosure.

[0099] For any type of part, and in order to support as fully as possible the lower surface 131 referred to as "downskin" of the supported portion 13, the slats 31 of the support 3 extend longitudinally very close to each other, so as to form spacings 32 of relatively small width compared to the thickness of the slats 31, and / or compared to the thickness of the side walls 11, 12. The application of the breaking force can then be carried out at the level of a first or last slat 31, extending at the level of one of the end edges of the support 3. This can be advantageous in particular if the slats extend transversely to the side walls 11, 12, as illustrated by way of example in Figures 2 and 3A.

[0100] However, in particular examples where the slats 31 extend parallel to the side walls 11, 12, as shown in particular in [Fig. 3B], and in the examples of aerodynamic parts in Figures 9 to 11, the application of the breaking force may be difficult to implement, due to the presence of the side walls 11, 12 which hinder access to the first and last slat 31. Indeed, the distance which separates the first and / or the last slat from the first or the second side wall 11, 12 may be substantially equal to the width of the spacing 32 which separates two slats 31, or may be at least of the same order of magnitude.

[0101] The particular example in Figures 9 and 10 proposes an improvement to further facilitate the removal of the support 3. By way of example, such an improvement is illustrated on a portion of the aerodynamic part in [Fig.4], but it is understood that such an improvement is suitable for all types of parts.

[0102] According to such an improvement, one or more of the slats 31 of the support 3 includes at least one notch 33 at its free end 312.

[0103] Typically, the notches form recesses opening vertically onto the outer end 312 of the slat 31 in question, and also cross transversely through said slat 31. In other words, the notch or notches 33 are made so as to create, at the outer end 312 of the slat 31, a "crenellated" shape, comprising a succession of solid parts 34 and one or more hollow parts 33 which constitute the notch or notches 33.

[0104] In other words, the lamella 31, comprising two lateral surfaces 342 each extending lengthwise to form the lamella 31, comprises at least one notch 33 open on each of the two lateral surfaces 342 to form passages crossing transversely the slat 31 from one side to the other. Thus, a notch 33 formed on a first slat 31 allows physical access to the lateral surface 342 of a second slat 31 adjacent to the first slat 31. In this way, it is easier to apply a transverse force to detach the slat 31 from the part 1. Moreover, depending on the height of the notch 33, it is possible to reach a point of application of the force F that is positioned lower, relative to the outer end 312 of the slat 31, than in the absence of a notch 33.

[0105] The notches 33 formed on the slats 31 of the support 3 can thus further facilitate the removal of the slats 31 after the fabrication of the blank part 10.They allow a more effective application of a transverse force F on the slats 31, which helps to break the slats 31 at their breakable zone, even in the presence of side walls 11, 12 extending very close to the support 3 and parallel to the slats 31, and / or in the case of greatly reduced spacings 32 between the slats 31 for better support of the supported portion 13. The notches 33 thus also contribute to a cleaner and more controlled separation between the support 3 and the part 1, which can prove crucial for maintaining the surface quality and dimensional accuracy of the nominal part 1.

[0106] The notches 33 can be distributed without any particular distribution, or on the contrary according to a precise pattern. It can be considered that when the support 3 comprises N successive lamellae 31 extending longitudinally, in a straight line or curve, the free external end 312 of a k-th lamella among the N lamellae comprises at least one notch 33 positioned opposite, in a transverse direction, a solid portion 34 of a (k+l)-th lamella 31. According to this definition, different patterns will now be described.

[0107] In particular, according to a specific example of notch distribution in a so-called "checkerboard" pattern, a notch 33 of a (kl)th slat 31 is formed, on one side of a solid portion 34 of a kth slat 31, opposite, in the transverse direction, a notch of a (k+l)th slat 31, on a second side of said solid portion 34 of the kth slat 31 opposite the first side. In this way, the notches 33 of every other slat 31 are aligned and are thus arranged "in a staggered pattern." This is notably the case in the example shown in [Fig. 9].

[0108] As illustrated in particular in [Fig. 9], such a motif is particularly suited to the use of pliers for removing the lamellae 31. Indeed, since the solid portions of the lamellae 31 are then accessible from both sides, it is possible to grasp them with pliers exerting two opposing forces F1, F2 so as to stress them transversely and break them. Of course, this motif is also suitable for the use of a chisel, with which one can apply force on one side only, or also on both sides, of each slat 31.

[0109] According to other examples, the slats 31 may include a single notch 33. For example, said notch may be positioned in the middle of the length of the slats 31. In particular, only one slat 31 out of two, or out of three, or more, may have one (or more) notch 33. Such a particular example may be especially suitable when the slats 31 are of reduced length and reduced thickness, so that a force F on a first slat may be sufficient to break the next slat as well, or even several of the following slats 31.

[0110] According to one embodiment, the number of slats 31 may depend on the length of the slat 31 in question. For example, the notches 33 may be distributed so that a notch is provided every 10 mm, 20 mm, or even 50 mm of the length of the slats 31.

[0111] Indeed, providing several notches 33 at different longitudinal positions of the slat 31 allows the adjacent slat to be stressed transversely at different points along its length, to ensure a homogeneous break at its internal end 311.

[0112] According to examples, the slats 31 may not include the same number of notches 33.

[0113] With reference to [Fig. 10], which represents, by way of non-limiting example, a first slat 31.1 and a second slat 31.2 positioned behind the first slat 31.1. The first slat 31.1 here, by way of example, comprises three notches evenly distributed along the longitudinal dimension of the slat. The notches 33 are distributed so as to allow the application of three distinct transverse forces F1, F2, and F3 through the passages formed by each notch 33.

[0114] In this example, each of the notches has a different height H. This makes it possible, in particular, to apply forces Fl, F2 and F3 at different heights on the second slat 31.2. Advantageously, this difference in height is proportional to the difference in height, in these longitudinal positions, of the entire slat 31, from its inner end 311 to its outer end 312.

[0115] In addition, the forces Fl, F2 and F3 are applied at distinct longitudinal positions, so as to break the second slat 31.2 uniformly. To this end, the notches 33 are spaced apart by a distance D2 dimensioned according to the length of the slats.

[0116] Of course, it is also possible that all the notches have the same height, or different heights from one slat 31 to another.

[0117] In general, the notches 33 can for example have a height H between 1mm and 50mm.

[0118] In this example, the bottom of the notch has two inclined faces and a horizontal side connecting the two inclined faces. This configuration is given by way of example and, in particular, allows for good manufacturability of notches by powder fusion. Other shapes are possible; in particular, it is possible to provide a rounded shape, or two rounded faces connected by a horizontal side, or other manufacturable shapes using this particular additive manufacturing process by powder fusion.

[0119] Furthermore, it is also possible that the notches 33 have a slightly flared shape at their vertically opening end, so as to facilitate the evacuation of the unsolidified powder 21 from the notches.

[0120] Generally, the spacing between two lamellae, which can be on the order of a tenth of a millimeter wide, may be too small to allow for proper natural evacuation of the powder. This is also the case when the lamellae 31 have notches 33. This can be a disadvantage because the powder 21 present at the end of melting in the spaces 32, and where applicable in the notches 33, must be removed, particularly to avoid hindering the support removal operations and any adjustments that may involve machining tools.

[0121] To this end, according to examples and in particular as shown in [Fig. 1 1], chamfers 35 can be added at the outer end 312 of one or more slats 31, at the junction with the manufacturing platform 22. These chamfers 35 make it possible to create passages, along the longitudinal direction of the slats 31, to facilitate the flow of the unfused powder 21 out of the gaps 32 and, where applicable, out of the notches 33, before the separation of the blank 10 of the part and the manufacturing platform 22.

[0122] Figure 12 shows a schematic representation of a part 10 having a The single lateral wall 11, in this case an internal ferrule, extends supported portions 13, formed, in this example, by blades. In an unshown variant, the ferrule 11 is an external ferrule, and the blades 13 extend radially towards the center of the ferrule. In yet another variant, the ferrule is an intermediate ferrule from which two respective annular rows of blades extend both radially outwards and radially inwards.

Claims

Demands

1. A blank (10) of a part (1) comprising a first side wall (11) from which a supported portion (13) projects, the blank (10) being produced by additive manufacturing comprising the melting and solidification of successive layers of powder along a vertical manufacturing direction V, the blank (10) comprising a support (3) for supporting the supported portion (13) during its manufacture, the support (3) extending under the supported portion (13) and comprising a plurality of lamellae (31) extending side by side, each lamella (31) extending along the manufacturing direction V from an internal end (311) connected to the supported portion (13) and forming a breakable zone at said internal end (311), to an external end (312), the support (3) being configured to be removed from the part (1),each of the lamellae (31) being configured to be broken at least at the level of said breakable zone by application of a force at its outer end (312) and in a direction transverse to a direction of elongation of the lamella (31).

2. A blank (10) according to the preceding claim, wherein the lamellae (31) extend substantially parallel to each other along their elongation direction.

3. A blank (10) according to any one of the preceding claims, comprising a second side wall (12), the supported portion (13) extending from the first side wall (11) to the second side wall (12), and the support (3) comprising the plurality of slats (31) extending under the supported portion (13) and between the first side wall (11) and the second side wall (12).

4. A blank (10) according to any one of the preceding claims, being a blank (10) of an annular aerodynamic or hydrodynamic part, wherein: - the supported portion (13) is a blade of the aerodynamic or hydrodynamic part comprising a leading edge (133) and a trailing edge (132), - the first lateral wall (11) is an inner ferrule, the slats (31) of the support (3) each extending lengthwise from the vicinity of the leading edge (133) to the vicinity of the trailing edge (132), forming a curve extending parallel to the first lateral wall (11).

5. A blank (10) according to claims 3 and 4, wherein the second side wall (12) is an external ferrule of the annular aerodynamic or hydrodynamic part.

6. A blank (10) according to any one of the preceding claims, the support comprising N successive slats extending along an elongation direction, the free outer end of a k-th slat among N slats comprising at least one notch (33) positioned opposite, along the direction transverse to the elongation direction of the slats (31), a solid portion (34) of a (k+l)-th slat (31).

7. A blank according to the preceding claim, wherein a notch (33) of a (kl)th lamella (31) is provided, on a first side of a solid portion (34) of a k-th lamella (31), opposite, in the direction transverse to the direction of elongation of the lamellae (31), a notch of a (k+l)-th lamella (31), on a second side of said solid portion (34) of the k-th lamella (31) opposite to the first side.

8. A blank according to any one of claims 6 or 7, wherein at least one notch (33) extends vertically so as to open onto the outer end (312) of the slat (31) over a height of between 1 and 50 mm.

9. A blank according to any one of the preceding claims, each slat (31) being separated from adjacent slats (31) by a distance DI between 0.1mm and 5mm.

10. A blank according to any one of the preceding claims, wherein one or more of the slats (31) comprise at their outer end (312) a chamfer (35).

11. A method for obtaining a part from a blank (10) of a part according to any one of the preceding claims, the method comprising the manufacture of the blank (10) of part comprising the support (3), by additive manufacturing comprising the melting and solidification of successive layers of powder.

12. A method according to the preceding claim, wherein the slats (31) extend longitudinally, and the method comprising breaking the slats (31) of the support (3) by applying a force along a direction transverse to the direction of elongation of the lamellae (31).

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