Turbine stator blades made of ceramic matrix composites

Abstract

A turbine stator blade made of a ceramic matrix composite material, comprising at least one hollow blade profile (100, 200, 300, 400, 500) having a trailing edge (BF) and a leading edge (BA), the blade comprising a first portion (110, 210, 310, 410, 510) and a second portion (120, 220, 320, 420, 520) different from the first portion, the first portion comprising an outer camber of the blade profile, the second portion comprising an inner camber of the blade profile, the first portion and the second portion being connected to each other via a connection interface (130, 230, 250, 260, 301, 302, 401) present at least on the trailing edge or the leading edge of the blade profile, the connection The interface (401) includes an overlapping area (402) between a first portion (410) and a second portion (420), the overlapping area existing on at least one longitudinal end of the blade profile (400) and intended to exist outside the airflow path (403) of the turbine, the blade also includes at least one platform (530), the platform existing on one longitudinal end of the blade profile (500) and including a first portion (531) integral with the outer arc surface (510) of the blade profile and a second portion (520) integral with the inner arc surface (520) of the blade profile, the first portion and the second portion of the platform being connected to each other at at least one bridging portion (533, 534) belonging to the overlapping area.

Description

Technical Field

[0001] The present invention relates to turbine blades made of ceramic matrix composite materials ("CMC materials"), and more particularly to turbine stator blades and methods for manufacturing the same. Background Art

[0002] The turbine distributor or stator is the part connected to the turbojet engine casing that channels or directs the main flow of gases, i.e. the heat flow. The turbine stage consists of a fixed blade group called the distributor or stator, followed by a moving blade group or rotor consisting of a turbine disk and moving blades.

[0003] The blades of the first stage distributor are usually hollow so as to be able to guide cooling air to the rotor located in the hub. A portion of this cooling air may also be desired to cool the distributor.

[0004] To produce these parts of the hot section of the turbine, ceramic matrix composite materials ("CMC" materials) have been proposed, since they have remarkable thermostructural properties. In fact, they have mechanical properties that make them suitable for constituting structural elements and are able to maintain these properties at high temperatures. In addition, the density of these CMC materials is much lower than that of the metallic materials usually used for the various elements of the hot section of the turbine. Therefore, they allow these parts to be reduced in mass while being suitable for use in high temperature environments.

[0005] However, there may be disadvantages in manufacturing these hollow parts with CMC materials. When making a hollow part, it may be necessary to use a core to maintain its shape. Therefore, after the part has been consolidated, it must be possible to constrain the geometry of the cavity of the hollow part in order to extract the core from it. Additional manufacturing difficulties are also related to the fact that the core must be able to withstand the temperatures associated with the manufacturing range; that the core can be extracted despite the geometry without residues; and / or that the core can be removed, for example, by chemical degradation, melting or dissolution.

[0006] It is desirable to have a stator blade that can withstand the high temperatures of a turbine without increasing its weight, while avoiding the use of cores in its manufacture. Summary of the invention

[0007] The present invention relates to a turbine stator blade made of a ceramic matrix composite material, which comprises at least one hollow blade profile and has a trailing edge and a leading edge, characterized in that it comprises a first part and a second part different from the first part, the first part comprising an outer arc surface of the blade profile, the second part comprising an inner arc surface of the blade profile, the first part and the second part being connected to each other via a connection interface present at least on the trailing edge or the leading edge of the blade profile.

[0008] Having a blade formed from two different parts allows to omit a core during its manufacture. The two parts can be manufactured separately, without the use of a core, before being assembled together. It is also possible to obtain the blade by common densification of previously reinforced preforms of the two parts, thereby maintaining the shape of the two parts. These two manufacturing possibilities are described in detail below. In addition to overcoming the disadvantages related to the use of a core during the manufacturing process, the invention also allows to introduce a function on only one of the two parts, without affecting the other part, such as a local thickening on one of the parts, a braiding variation between the two parts or on the same part of the blade, so that the blade is more adapted to the required needs.

[0009] In an exemplary embodiment, the blade comprises at least one vent hole on at least one of the trailing edge and the leading edge, the at least one vent hole extending between an interior space of the blade profile and an exterior surface of the blade profile.

[0010] The fact that the two parts of the blade are produced and then assembled at the connection interface also allows the addition of cooling solutions during the manufacture of the blade. The cooling operated by the vents is cooling by a film of air, also known as "film cooling". The vents may be on the trailing edge, allowing the trailing edge of the blade profile to be cooled. Alternatively or in combination, the vents may be on the leading edge, allowing the inner or outer camber of the blade profile to be cooled.

[0011] In an exemplary embodiment, the connection interface comprises an overlap area between the first portion and the second portion, which overlap area is present on at least one longitudinal end of the blade profile and is intended to be outside the flow path of the airflow of the turbine.

[0012] In an exemplary embodiment, the overlapping area is reinforced by at least one mechanical connection, such as a bolt connection. This allows reinforcing the connection interface between the two parts of the blade without disturbing the aerodynamic flow.

[0013] In an exemplary embodiment, the blade also includes at least one platform, which is present at one longitudinal end of the blade profile and includes a first portion integral with the outer arc surface of the blade profile and a second portion integral with the inner arc surface of the blade profile, the first portion and the second portion of the platform being connected to each other at at least one bridging portion belonging to the overlapping area.

[0014] This allows strengthening the connection interface between the two parts of the blade.

[0015] In an exemplary embodiment, the at least one spanning portion is reinforced by a mechanical connection, such as a bolted connection. This allows reinforcing the connection interface between the two parts of the blade without disturbing the aerodynamic flow over the blade profile.

[0016] In an exemplary embodiment, the connection interface includes a protrusion present on at least one of the trailing edge or the leading edge.

[0017] The present invention also relates to a method for manufacturing the above blade, comprising the following steps:

[0018] - providing a first fiber preform intended to form the outer camber of the blade profile and a second fiber preform intended to form the inner camber of the blade profile;

[0019] - densifying the first fiber preform and the second fiber preform by means of a ceramic matrix; and

[0020] - Assembling the first dense-fiber preform and the second dense-fiber preform by producing a connection interface present at least on the trailing edge or the leading edge of the blade profile.

[0021] In an exemplary embodiment, the assembling step includes forming at least one vent extending between an interior space of the blade profile and an exterior surface of the blade profile on at least one of the trailing edge and the leading edge.

[0022] In an exemplary embodiment, the connection interface produced during the assembling step comprises an overlap region between the first dense fiber preform and the second dense fiber preform, which overlap region is present on at least one longitudinal end of the blade profile and is intended to be outside the airflow path of the turbine.

[0023] In an exemplary embodiment, the first fiber preform and the second fiber preform together define at least one platform preform, which is intended to be present at one longitudinal end of the blade profile and comprises a first portion integral with the first fiber preform and a second portion integral with the second fiber preform, the first and second portions of the platform preform being connected to each other during assembly over at least one bridge portion belonging to the overlapping area.

[0024] In an exemplary embodiment, the connection interface produced during the assembling step comprises a protrusion present on at least one of the trailing edge and the leading edge of the blade profile.

[0025] The present invention also relates to another method for manufacturing the above blade, comprising the following steps:

[0026] - providing a first fiber preform intended to form an outer camber portion of the blade profile and a second fiber preform intended to form an inner camber portion of the blade profile;

[0027] - reinforcing the first fiber preform and the second fiber preform;

[0028] - holding in place a first reinforced fiber preform and a second reinforced fiber preform, between which there is at least one region for carrying the trailing edge or the leading edge of the blade profile; and

[0029] - Common densification of the first reinforced fiber preform and the second reinforced fiber preform held in place with a common ceramic matrix, the connection interface being formed by the common ceramic matrix on the load-bearing area between said fiber preforms.

[0030] In an exemplary embodiment, the method further comprises the steps of locally applying a volatile material on the load-bearing area before the co-densification step, and removing the volatile material after the co-densification step, thereby forming at least one vent extending between the interior space of the blade profile and the exterior surface of the blade profile on at least one of the leading edge and the trailing edge.

[0031] In an exemplary embodiment, the connection interface comprises an overlap region between the first dense fiber preform and the second dense fiber preform, the overlap region being present on at least one longitudinal end of the blade profile and intended to be outside the airflow path of the turbine.

[0032] In an exemplary embodiment, the first fiber preform and the second fiber preform together define at least one platform preform intended to be present at one longitudinal end of the blade profile, comprising a first portion integral with the first fiber preform and a second portion integral with the second fiber preform, the first and second portions of the platform preform being in contact over at least one bridging portion belonging to the overlapping zone when they are held in place.

[0033] In an exemplary embodiment, the connection interface comprises a protrusion present on at least one of the trailing edge and the leading edge of the blade profile.

[0034] In an exemplary embodiment, regardless of the manufacturing method implemented, the first fiber preform and the second fiber preform are produced by three-dimensional weaving.

[0035] The stator blade according to the invention has the advantage that it can be produced in different ways: by assembling and connecting a first part and a second part previously densified separately, or by assembling and connecting two fiber preforms via a common ceramic matrix during densification. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other characteristics and advantages of the invention emerge from the following description given with reference to the accompanying drawings, which show exemplary embodiments without any limiting character.

[0037] [ Figure 1 ] Figure 1A sectional view with respect to the longitudinal direction of a turbine stator blade according to a first embodiment of the invention is schematically and partially shown.

[0038] [ Figure 2A ] Figure 2A A perspective view of a blade profile according to a second embodiment of the invention is schematically and partially shown.

[0039] [ Figure 2B ] Figure 2B A perspective view schematically and partially shows a blade profile according to a third embodiment of the invention.

[0040] [ Figure 2C ] Figure 2C A perspective view of a blade profile according to a fourth embodiment of the invention is schematically and partially shown.

[0041] [ Figure 3 ] Figure 3 A perspective view schematically and partially shows a blade profile according to a fifth embodiment of the invention.

[0042] [ Figure 4 ] Figure 4 A blade according to a sixth embodiment of the invention is shown schematically and partially.

[0043] [ Figure 5 ] Figure 5 A perspective view schematically and partially shows a blade according to a seventh embodiment of the present invention. DETAILED DESCRIPTION

[0044] exist Figures 1 to 2C In the drawing, the connection interfaces 130 and 230 present between the first portion 110, 210 and the second portion 120, 220 of the blade are enlarged to improve their visibility.

[0045] Figure 1 1 is a cross-sectional view of a blade profile of a stator blade according to a first embodiment of the present invention. The cross section is taken transversely to the longitudinal direction Z (plane (XY)) of the blade.

[0046] The blade is made of a ceramic composite material and comprises a hollow blade profile 100. The blade profile 100 has a trailing edge BF and a leading edge BA. The blade comprises a first part 110 forming the outer camber of the blade profile 100 and a second part 120 forming the inner camber of the blade profile. The two parts 110 and 120 of the blade are connected to each other by a connection interface 130 present on the leading edge BA in the example shown. The two parts 110 and 120 of the blade are integrated on the connection interface 130 so as to form the blade profile 100.

[0047] More generally, the connection interface 130 is present on the trailing edge BF or on the leading edge BA, or on both the leading edge BA and the trailing edge BF.

[0048] The internal volume V of the blade profile 100 extends between its two longitudinal ends and forms a circulation channel for the cooling air flow. In order to guide the cooling air to the external surface of the blade profile 100 or around the various hot parts, the blade may include vents 101, 102, 103 and 104. For example, the vent 101 present on the trailing edge BF allows cooling of the trailing edge BF, the vent 102 present on the leading edge BA on the inner camber side allows cooling of the inner camber of the blade profile 100, and the vents 103 and 104 present on the outer camber side for 104 and on the leading edge BA on the inner camber side for 103 allow cooling of the outer camber of the blade profile 100. The vents 101 to 104 connect the internal volume V with the external volume of the blade profile in order to provide a passage for the cooling air. An example has been shown in which several vents are present, but when a single vent is present, this of course does not depart from the scope of the present invention.

[0049] Figure 2A , 2B 2C show different possible arrangements of air vents made on stator blades according to the invention.

[0050] exist Figure 2A In the embodiment of the invention, the vent 240 is present over the entire height of the blade profile 200 at the trailing edge BF. Thus, the connection interface 230 between the two parts 210 and 220 of the blade will only be present at the leading edge BA.

[0051] According to another example, the vents 241 to 249 are present over the entire height of the blade profile 200, but are separated by the connecting areas 250 and 260 between the two parts 210 and 220. The vents 241 to 249 may have a substantially constant cross section along their length, for example cylindrical (see Figure 2B ). Alternatively, the cross-section of these vents may vary along their length, the cross-section increasing as one moves in the direction of the outer volume of the blade profile, e.g. Figure 2C As shown. Figure 2C In the example of FIG. 2 , the vents 246 to 249 have a conical shape. Figure 2B and Figure 2C In the example shown, the ventilation openings 241 to 249 are evenly distributed along the longitudinal direction Z. However, if the ventilation openings are not distributed regularly along the longitudinal direction Z, this does not depart from the scope of the present invention.

[0052] More generally, the shape and position of the air vents are adjusted on the trailing or leading edge of the blade profile according to the cooling requirements of the blade and its surrounding elements.

[0053] In order to strengthen the connection between the two parts 110, 210 and 120, 220 of the blade, the connection interface 130, 230 between the two parts may be modified. Figure 3 , 4 5 and 5 show several examples of the connection interface between two parts of a blade according to the invention.

[0054] exist Figure 3 In , the connection interface 301, 302 comprises two protrusions present on the trailing edge BF and on the leading edge BA of the blade profile 300. Protrusions of this type allow strengthening the connection interface 301, 302 between the two parts 310 and 320 of the blade.

[0055] It is also possible to add vents on at least one of the two projections 301 and 302. It is also possible to have a projection on one of the trailing edge BF or the leading edge BA of the blade profile 300 and vents on the other edge extending over the entire height of the blade profile 300.

[0056] exist Figure 4 In the example, the connection interface 401 comprises an overlap area 402 between a first portion 410 and a second portion 420 of the blade, which overlap area 402 is present on the outer longitudinal end of the blade profile 400 outside the flow path 403 of the airflow. In this example, the overlap area 402 is on the leading edge BA of the blade profile 400, but the same type of overlap area 404 can also be found on the trailing edge BF.

[0057] also, Figure 4 The overlapping region 402 shown in FIG. 4 is arranged at the outer longitudinal end of the blade profile 400 , but it can also be arranged at the inner longitudinal end of the blade profile 400 .

[0058] Figure 5 The blade shown in comprises a blade profile 500 and two parts 510 and 520, which are assembled together to form the outer camber and inner camber of the blade profile. It also comprises an external platform 530 present at one longitudinal end of the blade profile 500. The external platform 530 defines a flow path 503. According to an exemplary embodiment of the present invention, the platform 530 comprises a first part 531 integral with the first part 510 of the blade and a second part 532 integral with the second part 520 of the blade. In the example shown, the two parts 531 and 532 of the platform 530 are connected to each other on two bridging parts 533 and 534. The parts 531 and 532 overlap on the bridging parts 533 and 534.

[0059] Figure 5Only an outer platform 530 of the blade is shown. However, the blade may comprise, at the other longitudinal end of the blade profile 500, an inner platform opposite the outer platform 530, which inner platform comprises two parts defined for the outer platform 530.

[0060] therefore, Figure 4 and Figure 5 A reinforcement of the connection between two parts 410, 510 and 420, 520 of a blade outside the flow path 403, 503 of the gas in the turbine is described. The advantage of this type of reinforcement outside the flow path is the ability to add mechanical connections such as bolted connections to these connection interfaces to reinforce them without changing the aerodynamic characteristics of the blade profile 400, 500.

[0061] A first example of a method of manufacturing a blade according to the invention is described below.

[0062] In this first example, the method comprises a first step of providing two fiber preforms. The first fiber preform is intended to form the outer camber of the blade profile 100 and is therefore intended to form Figure 1 The second fiber preform is intended to form the inner camber of the blade profile 100 and is therefore intended to form Figure 1 The second portion 120 of the blade is shown in FIG.

[0063] In a second step, the two fiber preforms are densified by a ceramic matrix. The ceramic matrix of the fiber preform can be made in whole or in part by chemical vapor infiltration, or in part or in whole by liquid means. The liquid technique can be a melt infiltration or polymer impregnation pyrolysis technique. The formation of a ceramic matrix by the above techniques is known per se. It is also possible to use a combination of these techniques to form the matrix. For example, the matrix can include silicon carbide.

[0064] Finally, in a third step, the first dense preform and the second dense preform are assembled, thanks to the creation of a connection interface present at least on the trailing edge or the leading edge of the blade profile.

[0065] The connection interface may be produced, for example, by applying adhesive to the two dense-fiber preforms on the trailing edge or the leading edge or by any other known means.

[0066] According to another example, the connection interface is formed by adding a joint between two dense fiber preforms.

[0067] According to an exemplary embodiment, the assembling step comprises forming at least one vent extending between an interior space of the blade profile and an exterior surface of the blade profile on a trailing edge or a leading edge of the blade profile.The shape of the fiber preform may be adapted to produce these vents.

[0068] It is also possible to create the vent without connecting certain areas of the leading and trailing edges of the blade profile.It is also possible to use a holding tool to constrain the vent size during assembly.

[0069] According to a further exemplary embodiment of the method according to the invention, in order to strengthen the connection between the two fiber preforms, the connection interface comprises an overlap area between the first dense fiber preform and the second dense fiber preform, which overlap area is present on at least one longitudinal end of the blade profile and is intended to be outside the flow path of the airflow of the turbine.

[0070] To produce this overlapping region, the shape of the fiber preform is adjusted during its production to form the desired overlapping region dimensions. During assembly, the two dense preforms are connected over the overlapping region in the same way as at the connection interface.

[0071] Mechanical connectors may also be added to this overlapping region to strengthen the connection between the two fiber preforms.

[0072] According to another exemplary embodiment, it is also possible to strengthen the connection between two fiber preforms, which together define at least one platform preform, which is intended to be present at one longitudinal end of the blade profile. The platform preform can be produced simultaneously with the first fiber preform and the second fiber preform. It comprises a first part that is integral with the first fiber preform and a second part that is integral with the second fiber preform. During the assembly of the dense fiber preform, the two parts of the platform are connected to each other on at least one bridging part of the overlapping area outside the airflow flow path belonging to the turbine.

[0073] According to an exemplary embodiment of the invention, in order to strengthen the connection between the two parts of the platform preform, a mechanical connection, such as a bolt connection, is added to the crossover part. This allows strengthening the connection between the two fiber preforms without changing the aerodynamic profile of the blade. It also allows placing a large number of vents on the trailing and leading edges of the blade profile to improve the cooling capabilities of the blade while maintaining a robust blade structure.

[0074] According to another exemplary embodiment, in order to strengthen the connection between the two fiber preforms, the connection interface may comprise a protrusion present on the trailing edge and / or the leading edge of the blade profile. The protrusion may be produced during the production of the two fiber preforms, during which the trailing edge and / or the leading edge of the two fiber preforms are extended axially (along the Figure 3 When assembling the two preforms, the extensions of the trailing edges and / or leading edges of the two dense fiber preforms are connected together to form a protrusion.

[0075] The connection of the extension of the fiber preform may be performed in the same way as the connection interface between two parts of the blade.

[0076] A second example of the method of manufacturing a blade according to the present invention is described below.

[0077] In the second manufacturing method, the first step includes providing an outer cambered portion (ie, Figure 1 The first fiber preform of the first portion 110 of the blade shown in FIG. 1 and the inner arc surface portion (ie, the inner arc surface portion) for forming the blade profile 100 Figure 1 1. The second fiber preform of the second portion 120 shown in FIG.

[0078] The second step consists in consolidating the two fiber preforms so that they are self-supporting. The consolidation step before assembly eliminates the need for a core to hold and assemble the two fiber preforms. The consolidation consists in partially filling the pores of the two fiber preforms with a consolidation matrix phase, allowing them to maintain their shape without the aid of a holding tool.

[0079] In a third step, the first and second reinforced fiber preforms are held in place and positioned to bear against each other on at least one bearing area present on the trailing edge or on the leading edge of the blade profile. It is also possible to have multiple bearing areas on the trailing edge and / or the leading edge.

[0080] Then in a fourth step, the two reinforced fiber preforms held in place are co-densified with a common ceramic matrix.The connection interface is also formed by the common ceramic matrix on the load-bearing region (or regions) between the two fiber preforms.

[0081] The densification techniques previously described for the first method may also be used in the common densification step of the second method.

[0082] According to an exemplary embodiment of the invention, the second method may further comprise a step of locally applying a volatile material on the load-bearing area between the two reinforced fiber preforms before the co-densification step, and a step of removing the volatile material after the co-densification. These additional steps allow forming at least one vent extending between the interior space and the exterior surface of the blade profile on the trailing edge or leading edge of the blade profile.

[0083] The use of a volatile material or a fusible material on the surface, such as a moisture-resistant material, such as a refractory varnish (containing boron nitride), allows to avoid densification by a common matrix of the surface. It therefore allows to not connect two reinforced fiber preforms held in place on the surface, forming a passage between the inside of the blade profile and the outside of the blade profile, for example to evacuate a cooling air flow.

[0084] According to another exemplary embodiment of the method according to the invention, in order to strengthen the connection between the two fiber preforms, the connection interface comprises an overlap region between the two dense fiber preforms, which overlap region is present on at least one longitudinal end of the blade profile and is intended to be outside the flow path of the airflow of the turbine. In order to form this overlap region, the shapes of the two provided fiber preforms are adjusted, and the connection between the two preforms in this region is made of a common ceramic matrix.

[0085] It is also possible to add a mechanical connection, such as a bolt connection, to this overlapping area in order to strengthen the connection between the two fiber preforms.

[0086] In order to strengthen the connection between the two preforms, the two preforms together define at least one platform preform, which is intended to be present at one longitudinal end of the blade profile. The platform preform comprises a first part integral with the first fiber preform and a second part integral with the second fiber preform. When the two reinforced fiber preforms are kept in place, the two parts of the platform preform are in contact on the bridging part belonging to the overlapping area. The two parts of the platform preform are connected on the overlapping area by a common ceramic matrix. Reinforcement means can also be added to it to improve the connection in this area.

[0087] According to an exemplary embodiment, in order to strengthen the connection between the two parts of the platform preform, a mechanical connection, such as a bolt connection, is added to the spanning part. This strengthens the connection between the two fiber preforms without changing the aerodynamic profile of the blade.

[0088] According to another exemplary embodiment of the method according to the invention, in order to strengthen the connection between the two fiber preforms, the connection interface may comprise a protrusion present on at least one of the trailing edge or the leading edge of the blade profile. The protrusion results from the axial extension (along the longitudinal axis) of the two fiber preforms on the trailing edge and / or the leading edge during their production. Figure 3 direction X), and the connection caused by the common ceramic matrix of the two preform extensions during joint densification.

[0089] Regardless of the first manufacturing method or the second manufacturing method, the first fiber preform 110 and the second fiber preform 120 can be generated by three-dimensional weaving. The wire used to form the preform can be ceramic, in particular silicon carbide or carbon. The preform can be formed in a forming tool, for example.

[0090] According to another exemplary embodiment of the present invention, the first preform and the second preform may be obtained by overlaying a plurality of unidirectional fiber webs or two-dimensional or three-dimensional fabric layers, regardless of the method.

[0091] Regardless of the first or second manufacturing method, the first fiber preform and the second fiber preform may include "notches" in which wedges or other holding tools may be placed to avoid depositing material on these notches, thereby forming vents on the trailing edge and / or leading edge. The advantage of using a wedge or any other holding tool is that the size of the vent can be calibrated.

Claims

1. A turbine stator blade made of a ceramic matrix composite material, comprising at least one hollow blade profile (100, 200, 300, 400, 500) and having a trailing edge (BF) and a leading edge (BA), characterized in that: The turbine stator blade comprises a first part (110, 210, 310, 410, 510) and a second part (120, 220, 320, 420, 520) different from the first part, the first part comprises an outer camber surface of the blade profile, the second part comprises an inner camber surface of the blade profile, the first part and the second part are connected to each other via a connection interface (130, 230, 250, 260, 301, 302, 401) at least present on the trailing edge or the leading edge of the blade profile, the connection interface comprises an overlap region (402) between the first part (410) and the second part (420), the overlap region existing on the blade profile. (400) at least one longitudinal end and exists outside the airflow path (403) of the turbine, wherein the blade also includes at least one platform (530), which exists at a longitudinal end of the blade profile (500), including a first portion integral with the outer arc surface (510) of the blade profile and a second portion (520) integral with the inner arc surface (520) of the blade profile, the first portion and the second portion of the platform are connected to each other at at least one bridging portion (533, 534) belonging to the overlapping area, so that one of the first portion of the platform or the second portion of the platform overlaps with the other portion of the platform at the bridging portion.

2. The turbine stator blade according to claim 1, characterized in that: The turbine stator blade comprises at least one vent (101, 102, 103, 104, 240 to 249) on at least one of the trailing edge and the leading edge, the at least one vent extending between an inner space (V) of the blade profile and an outer surface of the blade profile.

3. The turbine stator blade according to any one of claims 1 or 2, characterized in that: The connection interface (301, 302) comprises a protrusion present on at least one of the trailing edge and the leading edge of the blade profile (300).

4. A method for manufacturing a turbine stator blade according to any one of claims 1 to 3, comprising the following steps: - providing a first fiber preform forming the outer curved surface (110, 210, 310, 410, 510) of the blade profile (100, 200, 300, 400, 500) and a second fiber preform forming the inner curved surface (120, 220, 320, 420, 520) of the blade profile; - densifying the first fiber preform and the second fiber preform by means of a ceramic matrix; as well as - Assembling the densified first and second fiber preforms by producing a connection interface (130, 230, 250, 260, 301, 302, 401) present at least on the trailing edge (BF) or the leading edge (BA) of the blade profile.

5. The method according to claim 4, characterized in that The assembling step comprises generating at least one vent (101, 102, 103, 104, 240 to 249) on at least one of the trailing edge and the leading edge, the at least one vent extending between an inner space (V) of the blade profile and an outer surface of the blade profile.

6. The method according to claim 4, characterized in that The connection interface (401) comprises an overlap region (402) between the densified first fiber preform (410) and the second fiber preform (420), the overlap region being present on at least one longitudinal end of the blade profile (400) and being outside the airflow path (403) of the turbine.

7. The method according to claim 6, characterized in that The first fiber preform (510) and the second fiber preform (520) together define at least one platform preform (530), which is present at one longitudinal end of the blade profile (500) and comprises a first part (531) integral with the first fiber preform and a second part (532) integral with the second fiber preform, wherein during assembly, the first part and the second part of the platform preform are connected to each other at at least one bridging part (533, 534) belonging to the overlapping area, so that the first part of the platform or the second part of the platform overlaps with the other part of the platform at the bridging part.

8. The method according to any one of claims 4 to 7, characterized in that The connection interface (301, 302) comprises a protrusion present on at least one of the trailing edge and the leading edge of the blade profile (300).

9. A method for manufacturing a turbine stator blade according to any one of claims 1 to 3, comprising the following steps: - providing a first fiber preform forming the outer curved surface (110, 210, 310, 410, 510) of the blade profile (100, 200, 300, 400, 500) and a second fiber preform forming the inner curved surface (120, 220, 320, 420, 520) of the blade profile; - reinforcing the first fiber preform and the second fiber preform; - holding the first and second reinforced fiber preforms in place, between which there is at least one bearing area for bearing the trailing edge (BF) or the leading edge (BA) of the blade profile; as well as - co-densifying the first and second fiber preforms held in place and reinforced with a common ceramic matrix, the connection interface (130, 230, 250, 260, 301, 302, 401) being formed by the common ceramic matrix on the load-bearing area between the fiber preforms.

10. The method according to claim 9, characterized in that The method further comprises the steps of locally applying a volatile material on the bearing area before the co-densification step and removing the volatile material after the co-densification step, thereby forming at least one vent (101, 102, 103, 104, 240 to 249) extending between an interior space (V) of the blade profile and an exterior surface of the blade profile on at least one of the leading edge and the trailing edge.

11. The method according to claim 9, characterized in that The connection interface (401) comprises an overlap region (402) between the densified first fiber preform (410) and the second fiber preform (420), the overlap region being present on at least one longitudinal end of the blade profile (400) and being outside the airflow path (403) of the turbine.

12. The method according to claim 11, characterized in that The first fiber preform (510) and the second fiber preform (520) together define at least one platform preform (530), which is present at one longitudinal end of the blade profile (500) and includes a first portion (531) integral with the first fiber preform and a second portion (532) integral with the second fiber preform, and when they are held in place, the first portion and the second portion of the platform preform are in contact on at least one bridging portion (533, 534) belonging to the overlapping area, so that the first portion of the platform or the second portion of the platform overlaps with another portion of the platform on the bridging portion.

13. The method according to any one of claims 9 to 12, characterized in that The connection interface (301, 302) comprises a protrusion present on at least one of the trailing edge and the leading edge of the blade profile (300).

14. The method according to claim 4 or 9, characterized in that: The first fiber preform and the second fiber preform are produced by three-dimensional weaving.

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