Part obtained by powder injection

Abstract

The present invention relates to a part (50) obtained by injection moulding, in particular from a mixture comprising a binder and a powder, having a plurality of protuberances (40) projecting from a main face (241) of the part (50), the plurality of protuberances (40) comprising at least one first rib (41) and at least one second rib (42) intersecting at an intersection (400) comprising a midpoint (44) of the part (50).

Description

[0001] DESCRIPTION

[0002] TITLE: Part obtained by powder injection

[0003] TECHNICAL FIELD

[0004] The invention relates to a powder injection molding method, particularly in the aeronautical field. In particular, the present invention relates to the manufacture of parts, such as turbomachine blades, using such a powder injection molding method.

[0005] STATE OF THE ART

[0006] Metal injection molding technology, also known as MIM, consists of injection molding from a mixture of metal powder and polymer binder.

[0007] The powder can be a metal, for example a titanium or aluminum alloy, or a ceramic. The mixture forms a granulate, also known as "feedstock" in English, which is extruded and then cut into flakes, also known as "pellets" in English, to be received and molded in an injection press.

[0008] Such technology makes it possible to manufacture metal products while meeting high production rate needs with good repeatability and reproducibility.

[0009] Some parts molded by injection of metal powders can deform, crack and / or present imperfections after sintering, particularly when they have a complex and / or slender geometry.

[0010] Therefore, it can be difficult to apply the metal powder injection molding technique to manufacture turbomachine blades.

[0011] GENERAL STATEMENT

[0012] An aim of the present invention is therefore to improve powder injection molding, in particular for the manufacture of a turbomachine blade by powder injection. To this end, according to a first aspect of the invention, a part is provided obtained by injection molding, in particular from a mixture comprising a binder and a powder, the part comprising a plurality of protrusions extending in projection from a main face of the part. More specifically, the plurality of protrusions comprises at least one first rib and at least one second rib intersecting at an intersection comprising a midpoint of the part.

[0013] In particular, the powder comprises a metal and / or a ceramic. The part may comprise a turbomachine blade, the blade comprising a root, a heel and an airflow zone extending between the root and the heel. Where appropriate, each protrusion may extend projecting from a main face of the airflow zone.

[0014] Additionally, the plurality of protrusions may include:

[0015] - at least one third rib, the first rib, the second rib and the third rib being concurrent at the intersection; and / or

[0016] - at least two ribs connected to each other by an arch preferably having an arch, which advantageously forms one of the plurality of protuberances, the arch having a curvature facing away from the main face.

[0017] It may be provided that at least one of the protrusions, which is preferably a rib, comprises an upper edge having at least one flat. In particular, the upper edge is opposite the main face. Furthermore, the flat may take the form of a recess made in the upper edge. Preferably, the flat is configured to cooperate with a device for handling the part.

[0018] The part may also comprise at least one injection sprue extending from an external face of the part, typically an external face of the air vein zone, opposite the main face, in particular in a direction orthogonal to the external face, typically in a direction orthogonal to the air vein zone.

[0019] Furthermore, it may be provided that:

[0020] - two adjacent faces of a protuberance and / or two adjacent faces of the part, preferably of the foot or heel of the blade, are connected by at least one rounding;

[0021] - two adjacent faces, in particular internal faces, of the part, preferably of the foot or heel of the blade, which are oriented at an acute angle to each other, are connected by at least one radius;

[0022] - the plurality of protrusions comprises at least one reinforcement extending between the first rib and the second rib;

[0023] - the reinforcement extends from the intersection;

[0024] - the reinforcement connects a first face of the first rib to a second face of the second rib, the second face extending opposite the first face; and / or

[0025] - the part comprises at least one weight, preferably forming one of the plurality of protrusions, extending from an end portion of the part, typically the root or heel of the blade, and / or at least one boss, preferably forming one of the plurality of protrusions, connected to an end portion of the part, typically the root or heel of the blade.

[0026] According to a second aspect of the invention, a method is proposed for manufacturing a part, in particular a turbomachine blade, the method comprising at least one step of sintering a part according to the first aspect of the invention, the part resting on a support by means of the plurality of protuberances during the sintering step.

[0027] Additionally, the manufacturing process may also include at least one finishing step, during which protrusions from the part are removed.

[0028] According to a third aspect of the invention, there is provided a turbomachine blade obtained by means of a manufacturing method according to the second aspect of the invention.

[0029] According to a fourth aspect of the invention, there is provided a turbomachine comprising at least one blade according to the third aspect of the invention, and in particular a hub on which the blade is fixed.

[0030] According to a fifth aspect of the invention, there is provided an aircraft comprising a turbomachine according to the fourth aspect of the invention, the turbomachine being attached to an airframe of the aircraft.

[0031] DESCRIPTION OF FIGURES

[0032] The present invention will be better understood and other characteristics, aims and advantages will emerge from the detailed description which follows, comprising embodiments given for illustrative and non-limiting purposes, with reference to the appended figures, which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition, in which: Figure 1 is a schematic view from above of an aircraft; Figure 2 is a schematic half-sectional view of a turbomachine of an aircraft; Figure 3 is a schematic perspective view of a turbomachine blade; Figure 4a and Figure 4b schematically illustrate a deformation field of the blade of Figure 3; Figure 5 is a schematic perspective view of a part obtained by injection molding according to the invention; Figure 6 is a schematic front view of the part of Figure 5;Figures 7a to 8d are detailed views of various parts of the part of Figure 5; and Figure 9 is a flowchart of an embodiment of a manufacturing method according to the invention, in particular of a turbomachine blade.;

[0033] DETAILED DESCRIPTION

[0034] Figure 1 is a schematic top view of an aircraft 1. More specifically, the aircraft 1 is an apparatus configured to rise and move through the air, and may, for example, be an airplane, civil or military, a helicopter, etc.

[0035] According to an example presented in Figure 1, the aircraft 1 is an airplane comprising an airframe 10 composed of a fuselage, a wing comprising two wings, empennages, flight control surfaces and landing gear. The aircraft 1 further comprises a propulsion system 100 in order to give it the thrust necessary for its elevation and movement in the air.

[0036] Of course, the aircraft 1 may comprise a plurality of propulsion systems 100, for example one propulsion system 100 per wing according to the aircraft 1 illustrated as an example in FIG. 1.

[0037] Figure 2 is a schematic half-sectional view of a turbomachine 111 of the propulsion system 100 of the aircraft 1.

[0038] In particular, the propulsion system 100 thus comprises the turbomachine 111, having a main direction extending along a longitudinal axis X. The turbomachine 111 is configured to be fixed to the cell 10 of the aircraft 1, for example to the wings, in the case of the aircraft in FIG. 1, typically via a pylon. The turbomachine 111 can also be mounted at the rear of the fuselage, or even be integrated into the fuselage of the aircraft 1.

[0039] The turbomachine 111 may be a twin-spool, twin-flow, shrouded, and direct-drive turbomachine, as described below, but may also comprise a different number of spools and / or flows, and / or be another type of turbojet, such as a geared turbojet or a turboprop, shrouded or not. Unless otherwise specified, the terms “upstream” and “downstream” are used with reference to the overall direction of airflow through the propulsion system 100 in operation. Similarly, an axial direction corresponds to the direction of the longitudinal axis X and a radial direction is a direction orthogonal to the longitudinal axis X and intersecting the longitudinal axis X.

[0040] Furthermore, the adjectives "inner", or "internal", and "outer", "external", are used with reference to a radial direction so that an inner part of an element is, in the radial direction, closer to the longitudinal axis X than an outer part of the same element.

[0041] The turbomachine 111 comprises, from upstream to downstream in the direction of gas flow, a fan 1112, a primary body comprising a compression section comprising a low pressure compressor 1113 and a high pressure compressor 1114, a combustion chamber 1115, and a turbine section comprising a high pressure turbine 1116 and a low pressure turbine 1117.

[0042] The blower 1112 may be shrouded, that is to say it is housed in a retention casing 1111.

[0043] The blower can also be unducted, that is to say it is not housed in a retention casing and is in the form of propellers.

[0044] The air flow entering the turbomachine 111 following the suction generated by the fan 1112 and divides into a primary flow configured to pass through the primary body and a secondary flow configured to bypass the primary body.

[0045] Furthermore, the turbomachine 111 comprises a high pressure shaft 1118 connected to the high pressure turbine 1116 and configured to drive the high pressure compressor 1114, and a low pressure shaft 1119 connected to the low pressure turbine 1117 and configured to drive the low pressure compressor 1113 and the fan 1112.

[0046] The turbomachine 111 comprises blades 22 configured to be mounted on a hub.

[0047] Figure 3 is a schematic perspective view of a blade 22 of the turbomachine 111.

[0048] The blade 22 comprises a root 23, a heel 25 and an aerodynamic profile blade defining an airflow zone 24, that is to say a flow path of an air flow. The blade 22 further comprises a leading edge 27 and a trailing edge 28. The leading edge 27 corresponds to an upstream portion of the aerodynamic profile 24 extending opposite the airflow. The leading edge 27 divides the airflow into an intrados flow and an extrados flow.

[0049] The trailing edge 28 corresponds to a downstream part of the aerodynamic profile 24, where the intrados and extrados flows meet.

[0050] The root 23 is configured to be fixed on a hub of a mobile wheel and the heel 25 forms a free end. In the case of a rectifier, the root 23 of the blade 22 is configured to be, for example fixed, on a hub of the rectifier and the heel 25 is configured to be mounted on a shroud of the rectifier. Blades of this type are present elsewhere in the turbomachine 111, for example in the compression section and in the low pressure turbine 1117.

[0051] The blade 22 can be obtained by MIM powder injection molding. The powder injection molding process includes a sintering step. A shrinkage of a molded part, in particular the blade 22, during sintering can be 15% of the volume of the part, in particular when it is a blade 22.

[0052] However, it is important to precisely control the dimensions of this type of part.

[0053] In addition, a sintering temperature, generally above 1200°C, can cause deformations or cracks.

[0054] The blade 22 is all the more sensitive to the phenomenon of shrinkage and to the extreme temperature during sintering, as it has a generally asymmetrical structure, in particular with, at the level of the air vein zone 24, a thickness which can be up to 3.5 times less than a thickness of the root 23 and / or the heel 25, which generates phenomena of torsion and / or bending.

[0055] Figures 4a and 4b schematically illustrate a deformation field of the blade 22 of Figure 3. More specifically, Figures 4a and 4b illustrate in this regard the stress zones of the blade 22 during sintering.

[0056] In addition, other phenomena can occur during sintering, such as friction between the part and the frame on which it rests.

[0057] In the present description, an example of a part 50 manufactured by the powder injection molding process may comprise the blade 22, or even be the blade 22.

[0058] Figure 5 is a schematic perspective view of the part 50, in particular the blade 22, obtained by injection molding according to the invention. It is intended to mold the part 50 with a plurality of protrusions 40 serving both as stiffeners and as support on the frame during sintering, so that the part 50, such as the blade 22, deforms homogeneously.

[0059] Each protrusion 40 projects from a main face 241 of the part 50, in particular the air flow zone 24 in the case of the blade 22. Thus, during sintering, the part 50 rests on the frame via the plurality of protrusions 40 instead of resting via a support separate from the part 50.

[0060] Furthermore, the protrusions 40 make it possible to reduce the difference in thickness between the various zones of the part 50, such as the air vein zone 24 and the root 23 and / or the heel 25 in the case of the blade 22.

[0061] The protrusions 40 also make it possible to limit the number of contact points between the part 50 and the frame, thus reducing the friction generated during sintering.

[0062] The part 50 obtained by powder injection molding comprising the protuberances 40 is illustrated according to an example in figure 5.

[0063] The protrusions 40 extend projecting from the main face 241 of the part 50, for example from the intrados of the air vein zone 24 in the case of the blade 22, but could of course extend from the extrados of the air vein zone 24.

[0064] The protrusions 40 may vary in geometry as well as in number.

[0065] More particularly, each protuberance 40 has an end portion, opposite the main face 241 of the part 50. The end portion of the protuberance 40 forms an upper edge 401 of the protuberance 40.

[0066] The upper edge 401 of protuberance 40 may be punctate, or substantially punctate, i.e. having a minimal surface, or be surface-like, i.e. having a substantially extended surface.

[0067] More specifically, according to the invention, all of the upper edges 401 of the protuberances 40 extend in the same plane P, as can be seen in FIG. 6.

[0068] Such an arrangement makes it possible to define and form a contact surface between the frame and the part 50 during sintering.

[0069] In order to limit the bending and / or twisting of the part 50, the plurality of protrusions 40 comprises at least a first rib 41 and a second rib 42. The first rib 41 and the second rib 42 may intersect at an intersection 400. In particular, the intersection 400 comprises a midpoint 44 of the part 50, in particular of the airflow zone 24 in the case of the blade 22. The intersection 400 designates a geometric location of meeting of the two volumes formed by the first rib 41 and the second rib 42. The intersection 400 corresponds to a surface of the space comprising the midpoint 44, in particular centered on the midpoint 44. Furthermore, the midpoint 44 may correspond to the barycenter of the part 50.

[0070] Furthermore, such an arrangement of the first rib 41 and the second rib 42 makes it possible to take into account a reference point, in particular the midpoint 44, which remains fixed throughout the sintering. Thus, taking into account the reference point, in particular the midpoint 44, of the part 50 makes it possible to better control the shrinkage inherent in the sintering.

[0071] According to an example illustrated in Figure 5, the first rib 41 and the second rib 42 intersect at the intersection 400 comprising the midpoint 44. The first rib 41 and the second rib 42 form two branches of a “cross” pattern. The first rib 41 and the second rib 42 therefore form an angle between them. According to various embodiments, the first rib 41 and the second rib 42 can be separated or tightened depending on the bending and / or twisting undergone by the part 50 during sintering.

[0072] In order to further support the part 50, in particular the air stream zone 24 in the case of the blade 22, the plurality of protrusions 40 may further comprise at least one third rib 43, distinguishable from the first rib 41 and the second rib 42.

[0073] The third rib 43 may intersect with the first rib 41 and the second rib 42, in particular at the intersection 400.

[0074] According to the example illustrated in figure 5, the first rib 41, the second rib 42 and the third rib 43 are therefore concurrent at the intersection 400 and form three branches of a “star” pattern.

[0075] The first rib 41, the second rib 42 and the third rib 43 therefore form an angle between them. According to various embodiments, the first rib 41, the second rib 42 and the third rib 43 can be spaced apart or tightened depending on the intensity of the bending and / or the twisting undergone by the part 50 during sintering.

[0076] The first rib 41, the second rib 42 and / or the third rib 43 may have several geometric shapes, identical or distinct. In addition, the first rib 41, the second rib 42 and / or the third rib 43 may in particular be rectilinear.

[0077] In order to further support the part 50, in particular the air stream zone 24 in the case of the blade 22, the plurality of protrusions 40 may further comprise at least one reinforcement 45, preferably a plurality of reinforcements 45. An example of reinforcement 45 is illustrated in FIG. 8b.

[0078] The reinforcement 45 extends between the first rib 41 and the second rib 42, in particular from the intersection 400. In particular, the reinforcement 45 connects a first face 410, in particular a first lateral face 410, of the first rib 41 to a second face 420, in particular a second lateral face 420, of the second rib 42.

[0079] The plurality of protrusions 40 may comprise at least a fourth rib 46, distinguished from the first rib 41, the second rib 42 and the third rib 43.

[0080] According to the example illustrated in figure 5, the plurality of protuberances 40 comprises at least ten fourth ribs 46, in particular at least twelve fourth ribs 46, in particular sixteen fourth ribs 46.

[0081] In addition, as illustrated in Figure 7b, in order to further limit the sagging of the part 50, the plurality of protrusions 40 may further comprise at least one arch 47 connecting two ribs, in particular two fourth ribs 46, together. In particular, the arch 47 has a bend 471 having a curvature facing away from the main face 241. In particular, the curvature of the bend 471 may correspond to a concave hemispherical curvature of the arch 47.

[0082] Indeed, the arch 47 makes it possible to transfer part of the mass of the part 50, in particular of the air vein zone 24 in the case of the blade 22, to the protuberances 40.

[0083] Due to the significant sag in the center of the part 50, the arch 47 connects two fourth ribs 46 located in a central portion of the part 50. To transfer a greater portion of the mass of the part 50 to the protrusions 40, it may be further provided that the plurality of protrusions 40 comprises a plurality of arches 47.

[0084] According to an example illustrated in figure 5 and in more detail in figure 7b, the part 50 comprises a plurality of vaults 47 distributed in an arc between the first rib 41, the second rib 42 and / or the third rib 43.

[0085] The vault 47 connects two adjacent fourth ribs 46, in particular arranged on a portion of an ellipse between the first rib 41, the second rib 42 and / or the third rib 43.

[0086] According to another embodiment, the arch 47 can connect any protrusions 40 together. In addition to the problems related to the sintering of the part 50, deformations can also occur as soon as the “green” part is obtained due to a geometry of the part 50 which is not suitable for molding. This can also generate at least one of the following phenomena:

[0087] - strings of porosities generating a lack of material on part 50;

[0088] - difficulties in filling the mold which cause areas of concentration of mechanical stresses in the part 50, and / or

[0089] - a local variation in a 50 part withdrawal rate, more commonly known under the terminology of “black trace” or “segregation”.

[0090] Thus, in order to improve filling of the mold and / or uniform cooling of the part 50, it may be provided that two adjacent faces of a protuberance 40 and / or two adjacent faces of the part 50, such as two adjacent faces of the root 23 or of the heel 25 in the case of the blade 22, are connected by at least one rounding 48.

[0091] For example, as illustrated in Figure 7a and Figure 7b, roundings 48 can thus substitute:

[0092] - a projecting edge which would be formed by two adjacent faces 221, 222 of the heel 25; and / or

[0093] - a projecting edge which would be formed by two adjacent faces 461, 462 of the fourth rib 46.

[0094] Furthermore, it may be further provided that two adjacent internal faces of the part 50, such as two adjacent internal faces of the root 23 or of the heel 25 in the case of the blade 22, oriented at an acute angle to each other, are connected by at least one radius 52.

[0095] An example of a radius 52 which connects two adjacent faces 231, 232 of the heel 25 is illustrated in particular by way of example in figure 8a.

[0096] The radius 52 and the rounding 48 may preferably have a connection radius of between 0.2 mm and 2 mm. The protrusions 40 may also have a thickness of between 1 mm and 8 mm.

[0097] The part 50 may also comprise at least one boss 60 connected to an end portion of the part 50, an example of which is illustrated in FIG. 8c. The boss 60 may also be connected to the root 23 and / or to the heel 25 in the case of the blade 22.

[0098] Of course, the part 50 may comprise a plurality of bosses 60 connected to the end portions of the part 50, in particular to the foot 23 and / or to the heel 25 in the case of the blade 22. In addition to acting on a geometry of the part 50, it is also possible to act on a direction of injection of the mixture to improve the filling of the mold.

[0099] For this purpose, the part 50 may comprise an injection sprue 70, also designated by the English term “sprue”, extending from an external face 242 of the part 50, such as the air vein zone 24, opposite the main face 241, in particular in a direction orthogonal to the external face 242.

[0100] An example of the injection core 70 is further illustrated by way of example on the part 50 of FIG. 6, in which the injection core 70 extends projectingly and orthogonally from the main face 241 of the part 50, in particular from the extrados in the case of the blade 22.

[0101] In the example presented, the injection core 70 is centered on the midpoint 44. However, it may be provided that the injection core 70 is offset relative to the midpoint 44.

[0102] In order to avoid the formation of strings of porosity within the part 50, the part 50 may further comprise at least one weight 80 extending from an end portion of the part 50, in particular from the root 23 and / or the heel 25 in the case of the blade 22. The string of porosity is then offset in the weight 80 and no longer remains within the part 50.

[0103] An example of a weight 80 located at the heel 25 of the blade 22 is illustrated in figure 8d.

[0104] Figure 9 is a flowchart of an embodiment of a manufacturing method according to the invention, in particular of the blade 22 of the turbomachine 111.

[0105] The manufacturing method comprises at least one mixing step E1, during which a mixture is injected into a mold.

[0106] At the end of the E1 mixing step, a part, sometimes called a "green", is obtained. The part resulting from the E1 mixing step is held in place by the binder.

[0107] As a result, the manufacturing process comprises at least one debinding step E2, during which the binder is removed. The debinding step E2 can be carried out in different ways, in particular by aqueous, thermal or chemical means.

[0108] At the end of the E2 debinding step, a part, sometimes called “brown” is obtained.

[0109] The part resulting from the E2 debinding step, from which almost all of the binder has been removed, is very fragile, in particular because it is composed of approximately 40% air, and is only bound by remnants of the binder. The manufacturing process includes at least one E3 sintering step, during which the part resulting from the E2 debinding step is sintered. During the E3 sintering step, the part resulting from the E2 debinding step is subjected to a temperature close to the melting point of the powder. Such a temperature allows the grains to weld together to create a solid.

[0110] At the end of the E3 sintering step, a part, sometimes called a “grey” part, is obtained.

[0111] The part resulting from the E3 sintering step is composed only of the powder and has shrunk compared to a volume injected during molding, due to the spaces left by the binder.

[0112] The manufacturing method comprises at least one finishing step E4, during which the protrusions 40 of the part 50 are then removed, for example by machining. The feeder 80 and the injection sprue 70 are also removed.

[0113] In order to facilitate removal, in particular by machining, positioning of the part 50 can be improved by providing a flat 403 formed in the upper edge 401 of at least one of the protrusions 40. Indeed, thanks to the flat, the roughing phase in machining is no longer necessary. Thus, the manufacture of the blade is faster and less expensive.

[0114] Indeed, the main face 241 of the part 50, in particular the air flow zone 24 in the case of the blade 22, has a bearing surface of significant dimensions compared to the end parts of the part 50, such as the root 23 and the heel 25 in the case of the blade 22.

[0115] In addition, using the main face 241 for positioning makes it possible to limit the deformations of the part 50, for example by distributing more of the pressure forces exerted by a vice on the part 50.

[0116] The flat 403 formed in the upper edge 401 of at least one of the protrusions 40 is therefore configured to cooperate with a device for handling the part 50, in particular a vice in the case of machining, in order to be able to use the main face 241 during positioning.

[0117] According to an exemplary embodiment illustrated in particular in FIG. 7a, the flat 403 forms a recess in the upper edge 401 of the protuberance 40. In other words, the flat 403 extends in a plane that is not coplanar with a plane in which the upper edge 401 of the protuberance 40, or even of several protuberances 40, possibly of all the protuberances 40, extends. Thus, a distance between the plane in which the flat 403 extends and the main face 241 of the air stream zone 24 is less (or greater if the flat 403 is in relief) than a distance between the plane in which the upper edge 401 of the protuberance 40, or even of several protuberances 40, possibly of all the protuberances 40, extends and the main face 241 of the air stream zone 24.

[0118] In addition, as many flats 403 may be provided as there are contact points required to facilitate positioning of the part 50.

[0119] In this case, according to the example illustrated in Figure 5, four fourth ribs 46 of the part 50 each have a flat 403. The four points of contact thus obtained by the flats 403 form a plane support. Thus, thanks to the flats 403, there are only three degrees of freedom to eliminate by providing other additional points of contact on the part 50, for example at the leading edge 27 and the heel 23 in the case of the blade 22 as illustrated in Figure 6 and Figure 7a.

[0120] The blade 22 according to the invention is therefore suitable for a turbomachine and has, on a macroscopic level, a shape and dimensions identical to those of a blade manufactured using a method of the prior art. However, the blade 22 according to the invention differs therefrom in its microscopic structure. Thus, it has a grain size on average larger than that of a blade obtained by a method of the prior art.

[0121] In addition, the blade 22 according to the invention offers better creep resistance.

Claims

CLAIMS 1. Part (50) obtained by injection molding from a mixture comprising a binder and a powder, the part (50) comprising: - a turbomachine blade (22), the blade comprising a root (23), a heel (25) and an airflow zone (24) extending between the root (23) and the heel (25); and - a plurality of protrusions (40) extending projecting from a main face (241) of the air vein zone (24), the plurality of protrusions (40) comprising two ribs (46) and an arch (47), the arch (47) connecting the two ribs (46) together and having an arch (471) having a curvature facing away from the main face (241).

2. Part (50) according to claim 1, in which a protrusion (40) of the plurality of protrusions (40) comprises an upper edge (401) having a flat (403).

3. Part (50) obtained by injection molding from a mixture comprising a binder and a powder, the part (50) comprising: - a turbomachine blade (22), the blade comprising a root (23), a heel (25) and an airflow zone (24) extending between the root (23) and the heel (25); and - a plurality of protrusions (40) extending projecting from a main face (241) of the air vein zone (24), a protrusion (40) of the plurality of protrusions (40) comprising an upper edge (401) having a flat (403).

4. Part (50) according to claim 3, in which the plurality of protuberances (40) comprises two ribs (46) and an arch (47), the arch (47) connecting the two ribs (46) together and having a bend (471) having a curvature facing away from the main face (241).

5. Part according to any one of claims 1 to 4, in which the plurality of protrusions (40) comprises a first rib (41) and a second rib (42) intersecting at an intersection (400) comprising a midpoint (44) of the part (50).

6. Part (50) according to claim 5, in which the plurality of protrusions (40) comprises a third rib (43), the first rib (41), the second rib (42) and the third rib (43) being concurrent at the intersection (400).

7. Part (50) according to any one of claims 1 to 6, further comprising an injection core (70) extending from an external face (242) of the part (50) opposite the main face (241), preferably in a direction orthogonal to the external face (242).

8. Part (50) according to any one of claims 1 to 7, in which two adjacent faces (461, 462) of a protuberance (40) of the plurality of protuberances (40) and / or two adjacent faces (221, 222) of the part (50) are connected by at least one rounding (48).

9. Part (50) according to any one of claims 1 to 8, in which two adjacent internal faces (231, 232) of the part (50) oriented at an acute angle to each other are connected by at least one radius (52).

10. Part (50) according to any one of claims 5 to 9, in which the plurality of protrusions (40) comprises at least one reinforcement (45) extending between the first rib (41) and the second rib (42), preferably from the intersection (400), the reinforcement (45) preferably connecting a first face (410) of the first rib (41) to a second face (420) of the second rib (42) extending opposite the first face (410).

11. A part (50) according to any one of claims 1 to 10, further comprising a weight (80) extending from an end portion of the part (50) and / or a boss (60) connected to an end portion of the part (50).

12. Method for manufacturing a part (50) according to any one of claims 1 to 11, comprising a sintering step (E3), the part (50) resting on a support via the plurality of protuberances (40) during the sintering step (E3).

13. Manufacturing method according to claim 12, comprising a finishing step (E4) during which the protrusions (40) of the part (50) are eliminated.

14. Turbomachine blade (22) obtained by means of a manufacturing method according to any one of claims 12 and 13.

15. Turbomachine (111) comprising a blade (22) according to claim 14.

16. Aircraft (1) comprising a turbomachine (111) according to claim 15.

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