TURBINE GUIDE VANE MADE OF CERAMIC MATRIX COMPOSITE MATERIAL

Abstract

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) comprising an extrados face of the blade profile and a second portion (120, 220, 320, 420, 520) distinct from the first portion and comprising an intrados face of the blade profile, the first and second portions being connected to one another by a connection interface (130, 230, 250, 260, 301, 302, 401) present at least on the trailing edge or leading edge of the blade profile, the connecting interface (401) comprising a region (402) of overlap between the first (410) and second (420) portions, which is present on at least one longitudinal end of the blade profile (400) and intended to be present outside a flow path (403) of a gas stream of the turbine, the blade also comprising at least one platform (530) present at one longitudinal end of the blade profile (500), the platform comprising a first portion (531) integral with the extrados face (510) of the blade profile and a second portion (520) integral with the intrados face (520) of the blade profile, the first and second portions of the platform being connected to one another on at least one straddling portion (533, 534) belonging to the region of overlap.

Description

[0001] Description

[0002] Title of the invention: Turbine stator blade made of ceramic matrix composite material

[0003] Technical Field

[0004] The invention relates to turbine blades made of ceramic matrix composite material (“CMC material”), and in particular to turbine stator blades, as well as their manufacturing processes.

[0005] Previous technique

[0006] Turbine distributors or stators are components attached to the casing of a turbojet engine that channel and direct the gases of the primary flow, i.e., the hot flow. A turbine stage consists of a fixed blade called a distributor or stator, followed by a moving blade or rotor comprising a turbine disk and moving blades.

[0007] The vanes of the first stages of distributors are generally hollow to allow cooling air to be directed to the rotors located in the hub. Some of this cooling air may also be used to cool the distributor itself.

[0008] To manufacture these hot section components of turbomachinery, ceramic matrix composite materials (CMCs) have been proposed because they possess remarkable thermostructural properties. Indeed, they have mechanical properties that make them suitable for structural elements and the ability to retain these properties at high temperatures. Furthermore, these CMCs have a significantly lower density than the metallic materials typically used for hot section components of turbomachinery. This allows for a reduction in the mass of these parts while still being suitable for use in high-temperature environments. However, manufacturing these hollow parts from CMCs can present some drawbacks. It may be necessary to use a core during the manufacturing process to maintain the hollow part's shape.After the part has been consolidated, the geometry of the hollow part cavity must be constrained to extract the core. Additional manufacturing challenges arise from having cores capable of withstanding the temperatures associated with the manufacturing process and that are extractable despite a geometry without draft angles, and / or that can be eliminated, for example, through chemical degradation, melting, or dissolution.

[0009] It would be desirable to have a stator blade that can withstand the hot temperatures of a turbomachine without increasing its weight, while also eliminating the need for a core during its manufacture.

[0010] Description of the invention

[0011] The invention relates to a turbine stator blade made of ceramic matrix composite material comprising at least one hollow blade profile and having a trailing edge and a leading edge, characterized in that it comprises a first part comprising an extrados face of the blade profile and a second part distinct from the first part comprising an intrados face of the blade profile, the first and second parts being linked together by a bonding interface present at least on the trailing edge or the leading edge of the blade profile.

[0012] Having a blade composed of two distinct parts eliminates the need for a core during its manufacture. The two parts can be manufactured separately without a core before being assembled. It is also possible to obtain the blade by co-densifying preforms of the two parts, which have been previously consolidated to ensure they retain their shape. These two manufacturing methods will be detailed later. In addition to eliminating the drawbacks associated with using a core during manufacturing, the invention allows for the introduction of functionalities on only one of the two parts without affecting the other, such as localized thickening on one part, variations in the weave between the two parts, or variations within the same section of the blade, thus enabling the production of blades better suited to specific requirements.

[0013] In one embodiment, the blade includes at least one vent on at least one of the trailing edge and leading edge, said at least vent extending between an internal space of the blade profile and an external surface of the blade profile.

[0014] Manufacturing and then assembling the two blade halves at a connecting interface also allows for the addition of cooling solutions during blade fabrication. The cooling provided by the vent is air film cooling, also known as "film cooling" in English-language literature. The vent can be located on the trailing edge, thus cooling the trailing edge of the blade profile. Alternatively, or in combination with other methods, the vent can be located on the leading edge, cooling either the lower or upper surface of the blade profile.

[0015] In one embodiment, the linking interface includes an overlap zone between the first and second parts present on at least one longitudinal end of the blade profile and intended to be present outside a flow channel of a turbine gas flow.

[0016] In one embodiment, the overlap area is reinforced by at least one mechanical connection, for example, a bolted connection. This strengthens the interface between the two parts of the blade without disrupting the aerodynamic flow.

[0017] In one embodiment, the blade also includes at least one platform present at one longitudinal end of the blade profile, the platform comprising a first part attached to the extrados face of the blade profile and a second part attached to the intrados face of the blade profile, the first and second parts of the platform being linked together on at least one overlap portion belonging to the overlap zone.

[0018] This helps to strengthen the interface between the two parts of the blade.

[0019] In one embodiment, said at least overlapping portion is reinforced by a mechanical connection, for example a bolted connection. This makes it possible to strengthen the interface between the two parts of the blade without disturbing the aerodynamic flow over the blade profile.

[0020] In one embodiment, the linking interface includes a projecting portion present on at least one of the trailing edge or leading edge.

[0021] The invention also relates to a method for manufacturing a blade as described above, comprising the following steps:

[0022] - supply of a first fibrous preform intended to form the extrados face of the blade profile and a second fibrous preform intended to form the intrados face of the blade profile;

[0023] - densification of the first and second fibrous preforms by a ceramic matrix; and

[0024] - assembly of the first and second densified fibrous preforms by creating a bonding interface present on at least the trailing edge or the leading edge of the blade profile.

[0025] In one embodiment example, the assembly step includes the fabrication of at least one vent extending between an internal space of the blade profile and an external surface of the blade profile, on at least one of the trailing edge and the leading edge.

[0026] In one embodiment, the bonding interface produced during the assembly stage includes an overlap zone between the first and second densified fibrous preforms present on at least one longitudinal end of the blade profile and intended to be outside a flow channel of a turbine gas flow.

[0027] In one embodiment, the first and second fibrous preforms together define at least one platform preform intended to be present at a longitudinal end of the blade profile. The platform preform comprises a first part integral with the first fibrous preform and a second part integral with the second fibrous preform. During assembly, the first and second parts of the platform preform are joined together over at least one overlapping portion within the overlap zone. In one embodiment, the joining interface formed during the assembly step includes a protruding portion present on at least one of the trailing and leading edges of the blade profile.

[0028] The invention also relates to another method for manufacturing a blade as described above, comprising the following steps:

[0029] - supply of a first fibrous preform intended to form the extrados part of the blade profile and a second fibrous preform intended to form the intrados part of the blade profile;

[0030] - consolidation of the first and second fibrous preforms;

[0031] - maintaining the first and second consolidated fibrous preforms in position with at least one bearing zone on the trailing edge or leading edge of the blade profile between said consolidated fibrous preforms; and

[0032] - co-densification of the first and second consolidated fibrous preforms held in position with a common ceramic matrix, the bonding interface being formed by the common ceramic matrix on the support area between said fibrous preforms.

[0033] In one embodiment, the process also includes a step of locally applying a fugitive material to the bearing area, before the co-application step.¬ densification, and the removal of fugitive material, after the co-densification step, so as to form at least one vent extending between an internal space of the blade profile and an external surface of the blade profile, on at least one of the leading edge and trailing edge.

[0034] In one embodiment, the bonding interface includes an overlap zone between the first and second densified fibrous preforms present on at least one longitudinal end of the blade profile and intended to be outside a flow channel of a turbine gas flow.

[0035] In one embodiment, the first and second fibrous preforms together define at least one platform preform intended to be present at a longitudinal end of the blade profile, the platform preform comprising a first part attached to the first fibrous preform and a second part attached to the second fibrous preform, and when held in position, the first and second parts of the platform preform being brought into contact on at least one overlap portion belonging to the overlap zone.

[0036] In one embodiment, the linking interface includes a projecting portion present on at least one of the trailing edge and leading edge of the blade profile.

[0037] In one example of implementation, and regardless of the manufacturing process used, the first and second fibrous preforms are produced by three-dimensional weaving.

[0038] The stator blade according to the invention has the advantage of being able to be made in different ways: assembly and linking of the first and second parts previously densified separately or assembly and linking of the two fibrous preforms during densification by a common ceramic matrix.

[0039] Brief description of the drawings

[0040] Other features and advantages of the present invention will become apparent from the description given below, with reference to the attached drawings which illustrate examples of embodiment without any limiting character.

[0041] [Fig. 1] Figure 1 represents, schematically and partially, a turbine stator blade in cross-section with respect to the longitudinal direction according to a first embodiment of the invention.

[0042] [Fig. 2A] Figure 2A represents, schematically and partially, a perspective view of a blade profile according to a second embodiment of the invention.

[0043] [Fig. 2B] Figure 2B schematically and partially represents a perspective view of a blade profile according to a third embodiment of the invention. [Fig. 2C] Figure 2C schematically and partially represents a perspective view of a blade profile according to a fourth embodiment of the invention.

[0044] [Fig. 3] Figure 3 represents, schematically and partially, a perspective view of a blade profile according to a fifth embodiment of the invention.

[0045] [Fig. 4] Figure 4 represents, schematically and partially, a blade according to a sixth embodiment of the invention.

[0046] [Fig. 5] Figure 5 represents, schematically and partially, a perspective view of a blade according to a seventh embodiment of the invention.

[0047] Description of the implementation methods

[0048] In figures 1 to 2C, the interface of linkage 130 and 230 present between the first 110, 210 and second 120, 220 parts of the blade has been exaggerated in order to improve its visibility.

[0049] Figure 1 is a cross-sectional view of the blade profile of a stator blade according to a first embodiment of the invention. The section is taken transversely to the longitudinal direction Z of the blade (plane (XY)).

[0050] The blade is made of ceramic composite material and comprises a hollow 100 blade profile. The 100 blade profile has a trailing edge BF and a leading edge BA.

[0051] The blade comprises a first part 110 forming the upper surface of the blade profile 100 and a second part 120 forming the lower surface of the blade profile 100. The two parts 110 and 120 of the blade are connected by a linkage interface 130 located on the leading edge BA in the illustrated example. The two parts 110 and 120 of the blade are joined at the linkage interface 130 to form the blade profile 100.

[0052] More generally, the linkage interface 130 is present on the trailing edge BF or on the leading edge BA or both on the leading edge BA and on the trailing edge BF. The internal volume V of the blade profile 100 extends between its two longitudinal ends and forms a channel for the circulation of a cooling airflow. In order to direct the cooling air to the external surface of the blade profile 100 or to the surrounding hot parts, the blade may include vents 101, 102, 103 and 104. For example, vent 101 on the trailing edge BF cools the trailing edge BF, vent 102 on the leading edge BA on the lower surface cools the lower surface of the blade profile 100 and vents 103 and 104 on the leading edge BA on the upper surface for 104 and on the lower surface for 103 cool the upper surface of the blade profile 100.Vents 101 to 104 connect the internal volume V with the external volume of the blade profile to provide passages for cooling air. An example with multiple vents is shown, but the invention remains within the scope of this example even with a single vent.

[0053] Figures 2A, 2B and 2C represent different possible arrangements for vents made on a stator blade according to the invention.

[0054] In Figure 2A, the vent 240 is present along the entire height of the blade profile 200 on the trailing edge BF. The connecting interface 230 between the two parts 210 and 220 of the blade will therefore only be present on the leading edge BA.

[0055] In another example, vents 241 to 249 are present along the entire height of the blade profile 200, but are separated by connecting zones 250 and 260 between the two parts 210 and 220. Vents 241 to 245 can have a substantially constant cross-section along their length and, for example, be cylindrical (see Figure 2B). Alternatively, the cross-section of the vents can vary along their length, increasing towards the outer volume of the blade profile, as illustrated in Figure 2C. In the example in Figure 2C, vents 246 to 249 are conical. In the examples illustrated in figures 2B and 2C, the vents 241 to 249 are distributed uniformly along the longitudinal direction Z. However, it does not depart from the scope of the invention if the distribution of the vents along the longitudinal direction Z is not regular.More generally, the shape and location of the vents are adapted on the trailing or leading edges of the blade profile according to the cooling requirements of the blade and its surrounding elements.

[0056] To strengthen the connection between the two parts 110, 210 and 120, 220 of the blade, it is possible to modify the connecting interface 130, 230 between these two parts. Figures 3, 4, and 5 show some examples according to the invention of connecting interfaces between the two parts of the blade.

[0057] In Figure 3, the linking interface 301, 302 includes two projecting portions present on the trailing edge BF and on the leading edge BA of the blade profile 300. This type of projecting portion helps to reinforce the linking interface 301, 302 between the two parts 310 and 320 of the blade.

[0058] It is also possible to add vents on at least one of the two projecting portions 301 and 302. It is also possible to have a projecting portion on one of the trailing edges BF or leading edges BA of the blade profile 300 and to have on the other edge, a vent extending over the entire height of the blade profile 300.

[0059] In Figure 4, the connecting interface 401 includes an overlap zone 402 between the first 410 and second 420 parts of the blade present on the outer longitudinal end of the blade profile 400 outside a flow channel 403 of the gas flow. In this example, the overlap zone 402 is on the leading edge BA of the blade profile 400, but it is also possible to find the same type of overlap zone 402 on the trailing edge BF.

[0060] Furthermore, the overlap zone 402 shown in Figure 4 is located on the outer longitudinal end of the blade profile 400, but it can also be located on the inner longitudinal end of the blade profile 400.

[0061] The blade shown in Figure 5 comprises a blade profile 500 and two parts 510 and 520 assembled together to form an extrados face and an intrados face of the blade profile. It also comprises an external platform 530 located at one longitudinal end of the blade profile 500. The external platform 530 defines the flow channel 503. This platform 530 comprises, according to one embodiment of the invention, a first part 531 attached to the first part 510 of the blade and a second part 532 attached to the second part 520 of the blade.

[0062] The two parts 531 and 532 of the platform 530 are linked together on two overlapping portions 533 and 534 in the illustrated example. Parts 531 and 532 overlap on the overlapping portions 533 and 534.

[0063] Figure 5 only represents the outer platform 530 of the blade. However, the blade may include, on the other longitudinal end of the blade profile 500, an inner platform, opposite the outer platform 530, comprising two parts as defined for the outer platform 530.

[0064] Figures 4 and 5 illustrate the reinforcement of the connection between the two parts (410, 51) and (420, 520) of the blade outside a gas flow channel (403, 503) in the turbine. The advantage of this type of reinforcement outside the channel is the ability to add mechanical connections, such as bolted connections, to these interfaces to strengthen them without altering the aerodynamic properties of the blade profile (400, 500).

[0065] A first example of a method for manufacturing a blade according to the invention is described below.

[0066] In this first example, the process includes a first step of supplying two fibrous preforms. The first fibrous preform is intended to form the extrados face of the blade profile 100 and is therefore intended to form the first part 110 of the blade shown in Figure 1. The second fibrous preform is intended to form the intrados face of the blade profile 100 and is therefore intended to form the second part 120 of the blade shown in Figure 1.

[0067] In a second step, the two fibrous preforms are densified with a ceramic matrix. The ceramic matrices of the fibrous preforms can be produced entirely or partially by chemical vapor infiltration, or entirely or partially by liquid infiltration. The liquid infiltration technique can be melt infiltration or polymer impregnation and pyrolysis. The formation of a ceramic matrix using the aforementioned techniques is well-established. A combination of these techniques can also be used to form the matrices. The matrices can, for example, incorporate silicon carbide.

[0068] Finally, in a third step, the first and second densified preforms are assembled by means of a bonding interface present on at least the trailing edge or the leading edge of the blade profile.

[0069] The bonding interface can, for example, be achieved by bonding through the application of an adhesive to the two densified fibrous preforms on the trailing edge or the leading edge, or by any other known means.

[0070] In another example, the bonding interface is formed by adding a joint between the two densified fibrous preforms.

[0071] According to one embodiment, the assembly step includes the creation of at least one vent extending between an internal space of the blade profile and an external surface of the blade profile on the trailing or leading edge of the blade profile. To create these vents, the shape of the fibrous preforms can be adapted.

[0072] Vents can also be created by not connecting certain areas of the leading and trailing edges of the blade profile. Holding tools can also be used during assembly to constrain the vent dimensions.

[0073] According to another embodiment of the process according to the invention, to strengthen the bond between the two fibrous preforms, the bonding interface includes an overlap zone between the first and second densified fibrous preforms present on at least one longitudinal end of the blade profile and intended to be outside a flow channel of a turbine gas flow.

[0074] To create this overlap zone, the shape of the fibrous preforms is adapted during their fabrication to form the desired overlap zone size. During assembly, the two densified preforms are bonded at the overlap zone in the same way as at the bonding interface.

[0075] It is also possible to add a mechanical link to this overlap zone to reinforce the bond between the two fiber preforms. According to another embodiment, which also reinforces the bond between the two fiber preforms, the two preforms together define at least one platform preform intended to be present at one longitudinal end of the blade profile. The platform preform can be produced simultaneously with the first and second fiber preforms. It comprises a first part attached to the first fiber preform and a second part attached to the second fiber preform. During the assembly of the densified fiber preforms, the two parts of the platform are linked together over at least one overlapping portion belonging to the overlap zone outside the flow path of a turbine gas stream.

[0076] According to one embodiment of the invention, to reinforce the connection between the two parts of the platform preform, a mechanical connection, for example a bolted connection, is added to the overlapping portion. This strengthens the connection between the two fibrous preforms without altering the aerodynamic profile of the blade. It also allows for the placement of numerous vents on the trailing and leading edges of the blade profile to improve the blade's cooling capacity while maintaining a robust blade structure.

[0077] According to another embodiment, to strengthen the bond between the two fibrous preforms, the bonding interface can include a protruding portion on the trailing edge and / or the leading edge of the blade profile. This protruding portion can be created during the fabrication of the two fibrous preforms, during which the trailing and / or leading edges of both preforms are extended axially (along the X direction in Figure 3). During the assembly of the two preforms, the extensions of the trailing and / or leading edges of the two densified fibrous preforms are bonded together to form protruding portions.

[0078] The joining of the extensions of the fibrous preforms can be carried out in the same way as the joining interface between the two parts of the blade.

[0079] A second manufacturing process for a blade according to the invention is described below. In this second manufacturing process, the first step consists of providing a first fibrous preform intended to form the extrados part of the blade profile 100, i.e. the first part 110 of the blade shown in figure 1, and a second fibrous preform intended to form the intrados part of the blade profile 100, i.e. the second part 120 of the blade shown in figure 1.

[0080] The second step involves consolidating the two fibrous preforms to make them self-supporting. This consolidation step, prior to assembly, eliminates the need for a core to hold and join the two fibrous preforms together. Consolidation consists of partially filling the porosity of the two fibrous preforms with a consolidation matrix, allowing them to maintain their shape without the need for any holding tooling.

[0081] In a third step, the first and second consolidated fibrous preforms are held in position and positioned to bear against each other on at least one bearing zone present on the trailing edge or the leading edge of the blade profile. It is also possible to have several bearing zones on the trailing edge and / or the leading edge.

[0082] Then, in a fourth step, the two consolidated fibrous preforms held in position are co-densified with a common ceramic matrix. A bonding interface is also formed by the common ceramic matrix at the bearing area(s) between the two fibrous preforms.

[0083] The densification techniques previously described for the first process can also be used for the co-densification step of the second process.

[0084] According to one embodiment of the invention, this second method may also include a step of locally applying a fugitive material to the bearing area between the two consolidated fibrous preforms before the co-densification step, and a step of removing the fugitive material after co-densification. These additional steps make it possible to create at least one vent extending between an internal space and an external surface of the blade profile on the trailing or leading edge of the blade profile. The application of a fugitive material, such as an anti-wetting agent like refractory varnish (boron nitride), or a fusible material to a surface makes it possible to prevent densification by the common matrix of that surface.It therefore makes it possible not to bind the two consolidated fibrous preforms held in position on this surface, and thus to create a passage between the inside of the blade profile and the outside of the blade profile in order, for example, to evacuate a flow of cooling air.

[0085] According to another embodiment of the method according to the invention, to strengthen the bond between the two fibrous preforms, the bonding interface may include an overlap zone between the two densified fibrous preforms present on at least one longitudinal end of the blade profile and intended to be outside a flow path of a turbine gas stream. To form this overlap zone, the shape of the two supplied fibrous preforms is adapted, and the bond between the two preforms in this zone is made by the common ceramic matrix.

[0086] It is also possible to add a mechanical connection to the overlap area, for example a bolted connection, to reinforce the bond between the two fibrous preforms.

[0087] To strengthen the bond between the two preforms, the two fibrous preforms together define at least one platform preform intended to be present at one longitudinal end of the blade profile. The platform preform comprises a first part bonded to the first fibrous preform and a second part bonded to the second fibrous preform. When the two consolidated fibrous preforms are held in position, the two parts of the platform preform are brought into contact at an overlapping portion within the overlap zone. The two parts of the platform preform are bonded at the overlap zone by the common ceramic matrix. A reinforcing element can also be added to improve the bond at this zone.

[0088] In one embodiment, to strengthen the connection between the parts of the platform preform, a mechanical connection, for example a bolted connection, is added to the overlapping portion. This makes it possible to consolidate the connection between the two fibrous preforms without altering the aerodynamic profile of the blade.

[0089] According to another embodiment of the process according to the invention, to strengthen the bond between the two fibrous preforms, the bonding interface may include a protruding portion present on at least one of the trailing or leading edges of the blade profile. This protruding portion results from the axial extension (along the X direction in Figure 3) of the two fibrous preforms on their trailing and / or leading edges during their fabrication, and from the bonding of the extensions of the two preforms by the common ceramic matrix during co-densification.

[0090] For both the first and second manufacturing processes, the first 110 and second 120 fibrous preforms can be produced by three-dimensional weaving. The yarns used to form the preforms can be ceramic, particularly silicon carbide, or carbon. The preforms can, for example, be shaped in a forming tool.

[0091] According to another embodiment of the invention, the first and second preforms, regardless of the process, can be obtained by draping a plurality of unidirectional fibrous sheets or layers of two-dimensional or three-dimensional fabric.

[0092] For both the first and second manufacturing processes, the first and second fibrous preforms may include notches into which a shim or other holding tool can be placed to prevent material from being deposited on these notches and thus creating vents on the trailing and / or leading edges. The advantage of using shims or other holding tools is the ability to calibrate the size of the vents.

Claims

Demands

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 it comprises a first part (110, 210, 310, 410, 510) comprising an extrados face of the blade profile and a second part (120, 220, 320, 420, 520) distinct from the first part comprising an intrados face of the blade profile, the first and second parts being connected to each other by a bonding interface (130, 230, 250, 260, 301, 302, 401) present at least on the trailing edge or the leading edge of the blade profile, the bonding interface comprising an overlap zone (402) between the first (410) and second (420) parts present on at least one longitudinal end of the blade profile (400) and intended to be present outside a flow channel (403) of a turbine gas flow,characterized in that the blade also comprises at least one platform (530) present at a longitudinal end of the blade profile (500) which comprises a first part (531) integral with the extrados face (510) of the blade profile and a second part (520) integral with the intrados face (520) of the blade profile, the first and second parts of the platform being linked together on at least one overlap portion (533, 534) belonging to the overlap zone..,

2. Turbine stator blade according to claim 1 comprising at least one vent (101, 102, 103, 104, 240 to 249) on at least one of the trailing edge and leading edge, said at least vent extending between an internal space (V) of the blade profile and an external surface of the blade profile.

3. Turbine stator blade according to any one of claims 1 or 2, wherein the linking interface (301, 302) comprises a projecting portion present on at least one of the trailing edge and 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: - supply of a first fibrous preform intended to form the extrados face (110, 210, 310, 410, 510) of the blade profile (100, 200, 300, 400, 500) and a second fibrous preform intended to form the intrados face (120, 220, 320, 420, 520) of the blade profile; - densification of the first and second fibrous preforms by a ceramic matrix; and - assembly of the first and second densified fibrous preforms by creating a bonding interface (130, 230, 250, 260, 301, 302, 401) present on at least the trailing edge (BF) or the leading edge (BA) of the blade profile.

5. Method of manufacturing a blade according to claim 4 wherein the assembly step comprises making at least one vent (101, 102, 103, 104, 240 to 249) extending between an internal space (V) of the blade profile and an external surface of the blade profile, on at least one of the trailing edge and the leading edge.

6. A method of manufacturing a blade according to any one of claims 4 or 5 wherein the bonding interface (401) comprises an overlap zone (402) between the first (410) and second (420) densified fibrous preforms present on at least one longitudinal end of the blade profile (400) and intended to be outside a flow channel (403) of a turbine gas flow.

7. A method of manufacturing a blade according to claim 6 wherein the first (510) and second (520) fibrous preforms together define at least one platform preform (530) intended to be present at a longitudinal end of the blade profile (500), the platform preform comprising a first part (531) integral with the first fibrous preform and a second part (532) integral with the second fibrous preform, and during assembly, the first and second parts of the platform preform being linked together on at least one overlap portion (533, 534) belonging to the overlap zone.

8. Method of manufacturing a blade according to any one of claims 4 to 7 wherein the linking interface (301, 302) comprises a projecting portion 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: - supply of a first fibrous preform intended to form the extrados part (110, 210, 310, 410, 510) of the blade profile (100, 200, 300, 400, 500) and of a second fibrous preform intended to form the intrados part (120, 220, 320, 420, 520) of the blade profile; - consolidation of the first and second fibrous preforms; - maintaining the position of the first and second consolidated fibrous preforms with at least one bearing zone on the trailing edge (BE) or the leading edge (LE) of the blade profile between said consolidated fibrous preforms; and - co-densification of the first and second consolidated fibrous preforms held in position with a common ceramic matrix, the bonding interface (130, 230, 250, 260, 301, 302, 401) being formed by the common ceramic matrix on the support area between said fibrous preforms.

10. A method for manufacturing a blade according to claim 9 also comprising a step of local application of a fugitive material on the bearing area, before the co-densification step, and the removal of the fugitive material, after the co-densification step, so as to form at least one vent (101, 102, 103, 104, 240 to 249) extending between an internal space (V) of the blade profile and an external surface of the blade profile, on at least one of the leading edge and trailing edge.

11. A method of manufacturing a blade according to any one of claims 9 or 10 wherein the bonding interface (401) comprises an overlap zone (402) between the first (410) and second (420) densified fibrous preforms present on at least one longitudinal end of the blade profile (400) and intended to be outside a flow channel (403) of a turbine gas flow.

12. A method of manufacturing a blade according to claim 11 wherein the first (510) and second (520) fibrous preforms together define at least one platform preform (530) intended to be present on a longitudinal end of the blade profile (500), the platform preform comprising a first part (531) integral with the first fibrous preform and a second part (532) integral with the second fibrous preform, and during holding in position, the first and second parts of the platform preform being brought into contact on at least one overlap portion (533, 534) belonging to the overlap zone,

13. A method of manufacturing a blade according to any one of claims 9 to 12 wherein the bonding interface (301, 302) comprises a projecting portion present on at least one of the trailing edge and the leading edge of the blade profile (300).

14. A method for manufacturing a blade according to any one of claims 4 to 13 wherein the first and second fibrous preforms are made by three-dimensional weaving.