Method for manufacturing a turbine engine vane made of a composite material, resulting vane and turbine engine including same

The invention relates to a method of fabricating a turbine engine blade out of composite material comprising fiber reinforcement densified by a matrix, the blade comprising an airfoil, a platform situated at a longitudinal end of the airfoil, and at least one functional element projecting from the outside face of the platform. The method comprises:      The second preform portion comprises a set of yarn layers interlinked by weaving with at least one zone of non-interlinking being provided to make it possible to deploy the functional element preform relative to the first platform preform.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase entry under 35 U.S.C. § 371 of International Application No. PCT/FR2015/051337, filed on May 21, 2015, which claims priority to French Patent Application No. 1454607, filed on May 22, 2014, the entireties of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to turbine or compressor blades for a turbine engine, the blades being made of composite material comprising fiber reinforcement densified by a matrix.

The intended domain is that of gas turbines for aeroengines or for industrial turbines.

Proposals have already been made to make turbine engine blades out of composite material, the fiber reinforcement being obtained in particular from carbon or ceramic yarns and the matrix being made out of ceramic material or organic material or carbon.

Document WO 2010/061140 A1 describes a method of fabricating turbine rotor wheel blades out of composite material and incorporating an outer platform or head and an inner platform, by: making a fiber blank by multilayer weaving; shaping the blank by means of tooling in order to obtain a fiber preform having portions forming a preform for a blade airfoil and root, a preform for a blade head, and a preform for a blade inner platform; and then densifying the fiber preform with a matrix. The fiber blank is woven with a first portion in the form of a strip or sheet that is to form the preform for the blade airfoil and root and a second portion in the form of a strip or sheet that is to form the preform for the head and inner platform, the second portion crossing the first portion at the locations of the head and of the inner platform.

Document WO 2011/080443 A1 describes a similar method in which the fiber blank is woven with a first portion in the form of a strip or sheet that is to form a preform for a blade airfoil and root, a second portion in the form of a strip or sheet that is to form a preform for overlapping spoilers of the blade head, and a third portion in the form of a strip or sheet that is to form a preform for wipers of the blade head and a preform for a blade inner platform, the second and third portions crossing the first portion at the locations of the head and of the inner platform. Such a method is relatively complex to implement. In addition, making a woven fiber blank with two crossings leads to large amounts of stress on the yarns, which can lead to yarns breaking, in particular if they are made of carbon or ceramic.

Document US 2012/099982 discloses fabricating a turbine engine stator blade out of composite material with fiber reinforcement densified by a matrix and comprising an airfoil, a first platform situated at one longitudinal end of the airfoil, and at least one functional element extending from the outside face of the first platform.

OBJECT AND SUMMARY OF THE INVENTION

An object of the invention is to propose a simplified method for fabricating a turbine engine blade out of composite material as a single piece while limiting the stresses imposed on the yarns during the weaving of a fiber blank from which a preform of the blade is obtained.

In general manner, the invention provides a method of fabricating a turbine engine blade out of composite material comprising fiber reinforcement densified by a matrix, the blade comprising an airfoil, a first platform situated at one longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and at least one functional element projecting from the outside face of the first platform and connecting with said outside face in a direction that is substantially circumferential, the method comprising:making a single-piece fiber blank by multilayer weaving;shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for the blade airfoil and a second portion forming a preform for the first platform and a preform for at least one functional element; anddensifying the fiber preform with a matrix in order to obtain a composite material blade having fiber reinforcement formed by the preform and densified by the matrix and forming a single piece incorporating the airfoil, the first platform, and said at least one functional element;

in which method the second portion of the preform comprises a set of yarn layers interlinked by weaving with at least one non-interlinked zone being arranged therein enabling the or each functional element preform to be deployed relative to the preform for the first platform. The fiber blank portion corresponding to the second preform portion may include one or more yarn layers taken from the portion of the fiber blank corresponding to the airfoil preform at one or more locations positioned in the longitudinal direction, the airfoil preform being of varying thickness in the longitudinal direction.

The term “functional element” is used herein to mean a portion of a blade that projects from the outside surface of a platform, e.g. to form a wiper of an outer platform or “head” of a rotor blade, or a mounting hook projecting from the outside face of an outer platform or possibly of an inner platform of a stator blade, or indeed an abradable support element projecting from the outside face of an inner platform or possibly of an outer platform of a stator blade. The term “an inside face defining a flow passage” is used herein to mean the face of an inner or outer blade platform that, when the blade is inserted in a compressor or a turbine, is the face that is exposed to the stream of air or gas flowing through the compressor or the turbine. The terms “inner” and “outer” are used herein to designate the situation relative to the axis of the turbine engine on which the blade is mounted, the inner platform being closer to the axis than the outer platform, for example. The term “circumferential” is used herein relative to the axis of the turbine engine in which the blade is mounted.

With the method of the invention, the way the non-interlinked zones are arranged means that it is not necessary to make the fiber blank with separate woven sheets in order to obtain both a preform for a functional element and also a preform for a blade platform. Compared with the above-mentioned prior art, the number of crossings and the complexity of the fiber blank are thus reduced, thereby reducing the risk of breaking yarns, and simplifying the design of tooling for shaping the preform.

The set of layers of the second preform portion may include a group of yarn layers in common with the airfoil preform.

The portion of the fiber blank corresponding to the second preform portion may in part extend the portion of the blank corresponding to the airfoil preform, thereby avoiding the need for this portion to be crossed completely as in the above-mentioned prior art.

The shaping of the fiber preform may be performed so as to obtain a single-piece fiber preform also having a third portion forming a preform for a second platform situated at a longitudinal end of the airfoil remote from its end where the first platform is located, and the set of yarn layers of the fiber blank portion corresponding to the second preform portion may then include a group of yarn layers in common with the portion of the fiber blank corresponding to the airfoil preform and a group of yarn layers in common with the blank portion corresponding to the second platform preform.

In a first implementation of the invention, the method seeks to fabricate a turbine engine rotor blade, the blade being made of composite material comprising fiber reinforcement densified by a matrix and comprising a root, an airfoil, an outer platform forming a head situated at one longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and head wipers each projecting from the outside face of the head and connecting with said outside face in a direction that is substantially circumferential, the method comprising:making a single-piece fiber blank by multilayer weaving;shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for the airfoil, a second portion forming a preform for the head and preforms for the wipers, and a third portion extending the first portion and forming a preform for the root; anddensifying the fiber preform with a matrix in order to obtain a composite material blade having fiber reinforcement formed by the preform and densified by the matrix and forming a single piece incorporating the root, the airfoil, the head, and the head wipers;

in which method the second portion of the preform comprises a set of yarn layers interlinked by weaving with non-interlinked zones being arranged therein enabling the preforms for the head wipers to be deployed relative to the preform for the head. The fiber blank portion corresponding to the second preform portion may include one or more yarn layers taken from the portion of the fiber blank corresponding to the airfoil preform at one or more locations positioned in the longitudinal direction, the airfoil preform being of varying thickness in the longitudinal direction.

The set of layers of the second preform portion may include a group of yarn layers in common with the blade preform. The set of layers of the second preform portion may also include a group of additional yarn layers that are not in common with the blade airfoil preform.

The shaping of the fiber preform may be performed so as to obtain a single-piece fiber preform also having a fourth portion forming a preform for an inner platform. Under such circumstances, the set of yarn layers of the fiber blank portion corresponding to the second preform portion may include a group of yarn layers in common with the portion of the fiber blank corresponding to the airfoil preform and a group of yarn layers in common with the blank portion corresponding to the inner platform preform. Still under such circumstances, the preform may include a set of yarn layers in common with the root preform and crossed by a set of yarn layers of the inner platform preform at the location of the inner platform.

The root preform may comprise a number of yarn layers that is greater than the number of yarn layers of the airfoil preform, and, in the fiber blank, the set of yarn layers of the portion of the blank corresponding to the second preform portion includes a group of yarn layers in common with the portion of the blank corresponding to the airfoil preform, and a group of yarn layers in common with the portion of the blank corresponding to the root preform and not used in the airfoil preform. A group of yarn layers used in the portion of the blank corresponding to the root preform is thus recovered from the portion of the blank corresponding to the second preform portion. The set of layers of the second preform portion may also include an additional group of yarn layers not in common with the root preform.

In a second implementation of the invention, the method seeks to fabricate a turbine engine stator blade, the blade being made of composite material comprising fiber reinforcement densified by a matrix and comprising an airfoil, a first platform situated at one longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and mounting hooks projecting from the outside face of the first platform and connecting with said outside face in a direction that is substantially circumferential, the method comprising:making a single-piece fiber blank by multilayer weaving;shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for the airfoil, a second portion forming a preform for the first platform, and preforms for the mounting hooks; anddensifying the fiber preform with a matrix in order to obtain a composite material blade having fiber reinforcement formed by the preform and densified by the matrix and forming a single piece incorporating the airfoil, the first platform, and the mounting hooks;

in which method the second portion of the preform comprises a set of yarn layers interlinked by weaving with non-interlinked zones being arranged therein enabling the mounting hook preforms to be deployed relative to the preform for the first platform. The fiber blank portion corresponding to the second preform portion may include one or more yarn layers taken from the portion of the fiber blank corresponding to the airfoil preform at one or more locations positioned in the longitudinal direction, the airfoil preform being of varying thickness in the longitudinal direction.

The preform of the first platform may be an outer platform preform or an inner platform preform.

The set of layers of the second preform portion may include a group of yarn layers in common with the airfoil preform.

In a third implementation of the method of the invention, the invention provides a method of fabricating a turbine engine stator blade, the blade being made of composite material comprising fiber reinforcement densified by a matrix and comprising an airfoil, a first platform situated at one longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and at least one abradable support element projecting from the outside face of the first platform and connecting with said outside face in a direction that is substantially circumferential, the method comprising:making a single-piece fiber blank by multilayer weaving;shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for the airfoil, a second portion forming a preform for the first platform, and at least one preform for an abradable support element; anddensifying the fiber preform with a matrix in order to obtain a composite material blade having fiber reinforcement formed by the preform and densified by the matrix and forming a single piece incorporating the airfoil, the first platform, and at least one abradable support element;

in which method the second portion of the preform comprises a set of yarn layers interlinked by weaving with non-interlinked zones being arranged therein enabling the or each abradable support element preform to be deployed relative to the preform for the first platform. The fiber blank portion corresponding to the second preform portion may include one or more yarn layers taken from the portion of the fiber blank corresponding to the airfoil preform at one or more locations positioned in the longitudinal direction, the airfoil preform being of varying thickness in the longitudinal direction.

The first platform preform may be an inner platform preform or an outer platform preform.

The set of layers of the second preform portion may include a group of yarn layers in common with the airfoil preform.

The first and second implementations of the method of the invention may be combined with each other in order to fabricate a turbine engine stator blade out of composite material incorporating a blade, an outer platform, mounting hooks, an inner platform, and at least one abradable support element.

In any method of the invention, in the fiber blank, said set of yarn layers may comprise warp yarn layers running in the longitudinal direction of the blade, and said non-interlinked zones then run continuously in the warp direction between opposite sides of the fiber blank portion corresponding to the second preform portion over a distance that is limited in the weft direction.

In any method of the invention, in the fiber blank, said set of yarn layers may comprise weft yarn layers running in the longitudinal direction of the blade, and said non-interlinked zones then run continuously in the weft direction between opposite sides of the fiber blank portion corresponding to the second preform portion over a distance that is limited in the warp direction.

The invention also provides a turbine engine blade comprising an airfoil, a first platform situated at a longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and at least one functional element extending from the outside face of the first platform and connecting with said outside face in a direction that is substantially circumferential;the blade being a single piece of composite material comprising multilayer woven fiber reinforcement densified by a matrix; andthe fiber reinforcement being a single piece with a first portion forming reinforcement for a blade airfoil and a second portion forming reinforcement for a first blade platform and for at least one functional element;

in which blade the second fiber reinforcement portion comprises a set of yarn layers all interlinked by weaving, apart from in a separation zone between the reinforcement for the or each functional element and the reinforcement for the first platform.

In a first particular embodiment of a blade of the invention, the blade is a turbine engine rotor blade comprising an airfoil, an outer platform forming a blade head situated at a longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and head wipers extending from the outside face of the head and connecting with said outside face in a direction that is substantially circumferential;the blade being a single piece of composite material comprising multilayer woven fiber reinforcement densified by a matrix; andthe fiber reinforcement being a single piece with a first portion forming reinforcement for the airfoil and a second portion forming reinforcement for the head and reinforcement for the head wipers;

in which blade the second fiber reinforcement portion comprises a set of yarn layers all interlinked by weaving, apart from in separation zones between the reinforcement for the head wipers and the reinforcement for the head.

In a second particular implementation of the blade of the invention, the blade is a turbine engine stator blade comprising an airfoil, a first platform situated at a longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and blade mounting hooks extending from the outside face of the first platform and connecting with said outside face in a direction that is substantially circumferential;the blade being a single piece of composite material comprising multilayer woven fiber reinforcement densified by a matrix; andthe fiber reinforcement being a single piece with a first portion forming reinforcement for the airfoil and a second portion forming reinforcement for the first platform and reinforcement for the mounting hooks;

in which blade the second fiber reinforcement portion comprises a set of yarn layers all interlinked by weaving, apart from in separation zones between the reinforcement for the mounting hooks and the reinforcement for the first platform.

The first platform may be an outer platform or an inner platform.

In a third particular embodiment of a blade of the invention, the blade may be a turbine engine stator blade comprising an airfoil, a first platform situated at a longitudinal end of the airfoil and having an inside face defining a flow passage and an outside face opposite from the inside face, and at least one abradable support element extending from the outside face of the first platform and connecting with said outside face in a direction that is substantially circumferential;the blade being a single piece of composite material comprising multilayer woven fiber reinforcement densified by a matrix; andthe fiber reinforcement being a single piece with a first portion forming reinforcement for the airfoil and a second portion forming reinforcement for the first blade platform and reinforcement for at least one abradable support element;

in which blade the second fiber reinforcement portion comprises a set of yarn layers all interlinked by weaving, apart from in separation zones between the reinforcement for the or each abradable support element and the reinforcement for the first platform.

The first platform may be an inner platform or an outer platform. The second and third embodiments of a blade of the invention may be combined with each other to form a turbine engine stator blade made out of composite material incorporating a blade, an outer platform, mounting hooks, an inner platform, and at least one abradable support element.

In all embodiments of a blade of the invention, the set of yarn layers of the second reinforcement portion may include a group of yarn layers in common with the airfoil reinforcement.

The invention also provides a turbine or compressor wheel for a turbine engine including blades as defined above made out of ceramic matrix composite material, or a turbine engine compressor wheel including blades as defined above made out of organic matrix composite material, and also a turbine engine having at least one such turbine or compressor wheel.

DETAILED DESCRIPTION OF EMBODIMENTS

The invention is applicable to various types of turbine engine blade, in particular to rotor wheel blades and to stator wheel blades for a turbine or a compressor in various spools of a gas turbine. The term turbine or compressor “stator wheel” is used herein to mean a set of non-rotary blades forming a nozzle of a turbine or a set of guide vanes of a compressor.

Embodiment: Rotor Wheel Blade for a Low Pressure Turbine

The low pressure turbine shown very diagrammatically and in part inFIG. 1comprises a plurality of stator wheels100alternating with a plurality of rotor wheels200in the direction of the axis X of the turbine, with the figure showing only a single pair comprising only a stator wheel and a rotor wheel.

A stator wheel100comprises a plurality of stator blades or “vanes”110, each having an airfoil120extending between an inner platform130and an outer platform140. Support elements162,164project inwards from the outside face of the inner platform130and connect with this outside face along connection zones extending in a substantially circumferential direction. The support elements162and164have an L-shaped profile and they support a block of abradable material166. Mounting hooks152and154project outwards from the outside face of the outer platform140and connect with this outside face along connection zones that extend in a substantially circumferential direction. The hooks152and154enable the blade to be assembled in a turbine casing10.

A rotor wheel200comprises a plurality of blades210(FIGS. 1 and 2), each having an airfoil220extending in a longitudinal direction between an inner platform230and an outer platform or “head”240. A root260formed by a portion of greater thickness, e.g. having a bulb-shaped section, is connected by a tang262to the outside face of the inner platform230. Head wipers252and254project outwards from the outside surface of the head240and connect with the outside face along connection zones extending in a substantially circumferential direction.

The outside faces of the platforms130and230, and the inside faces of the platform140and of the head240define a flow passage for the gas stream flowing through the turbine.

Each blade210is mounted on a turbine rotor20by its root260engaging in a housing of complementary shape formed at the periphery of the rotor. In its upstream and downstream end portions (upstream and downstream in the flow direction S of the gas stream), the platform230is terminated by upstream and downstream spoilers232and234. In cross-section, the airfoil220presents a curved profile of thickness that varies between its leading edge220aand its trailing edge220b. The thickness of the airfoil may also vary in the longitudinal direction. The upstream and downstream head wipers252and254have tooth-shaped profiles with tips that can penetrate into a layer of abradable material14carried by a turbine ring18in order to reduce clearance between the blade tip and the turbine ring. In its upstream and downstream end portions, the head240may likewise terminate in upstream and downstream spoilers242and244. The turbine rotor carries wipers22having ends that can penetrate into the abradable material166in order to seal the flow passage for the gas stream on the inside.

An arrangement for a low pressure turbine engine turbine as described briefly above is itself known.

FIGS. 3 and 4A to 4Dshow very diagrammatically a fiber blank300from which a fiber preform for a blade can be shaped so that, after densification by a matrix and possibly after machining, a blade is obtained that is made out of composite material, and that is of the type shown inFIG. 2, incorporating an airfoil, a root, an inner platform, a head, and head wipers.

In this embodiment, as in all of the other embodiments described below, the fiber blank is made by three-dimensional or multilayer weaving, and only the outlines of the various woven portions of the blank are shown for reasons of clarity (except inFIGS. 5A to 5D). By way of example, the weaving is performed with the warp direction corresponding to the longitudinal direction of the blade that is to be made, each blank portion comprising a plurality of warp yarn layers interlinked at least in part by weft yarns in a plurality of weft yarn layers.

The blank300comprises a portion302that is to form the preform for the airfoil of the blade that is to be made. The portion302may present smaller thickness in its lateral portions3021,3022adjacent to the leading and trailing edges of the airfoil of the blade that is to be made than in its central portion3023, with the difference in thickness being obtained in this example by having a different number of layers of warp yarns.

The blank300also has a portion306with a segment3061that is to form the preform for the root of the blade that is to be made and a segment3062that is to form the preform for the tang form of the blade that is to be made. The portion302lies in continuity with the segment3062of the portion306and shares common warp yarn layers therewith. Nevertheless, in this example, the portion3062has thickness that is greater than the thickness of the portion3023, this extra thickness being obtained by a greater number of layers of warp yarns, such that some of the layers of warp yarns in the portion306are not to be found in the portion302. The segment3061presents thickness that is greater than the thickness of the segment3062so as to present a shape corresponding to the shape of the bulb of the root of the blade that is to be made. This greater thickness may be obtained by increasing the weight and/or the thread count of the weft yarns. In a variant or in addition, an insert may be inserted locally during weaving. For a more detailed description of making a fiber blank portion corresponding to a blade root preform, reference may be made by example to the above-mentioned Document WO 2010/061140 A1.

The blank300also has a portion303that extends along a face306aof the portion306without being interlinked with the portion306. The warp yarns of the warp yarn layers of the portion303pass through the portion302where it connects with the portion306. The excess warp yarn layers of the portion306, i.e. those that are not taken up in the portion302are united by weaving with the layers of the portion303after it has passed through the portion302, in order to form a portion305. The portion305extends along the face302bof the portion302that is opposite from the face302acorresponding to the face306aof the portion306. The portion305is not interlinked by weaving with the portion302on its path running along it.

At the end of the portion302remote from its end that is connected to the portion306, a portion304is formed extending the portions302and305, while uniting them by weaving, at least some of the layers of yarns of the portion305possibly being found beside the face304aof the portion304that corresponds to the face302aof the portion302.

A segment303A of the portion303running along the face306aof the portion306and a segment305A of the portion305extending the segment303A and running along the face302bof the portion302are for use in forming the preform for the inner platform of the blade to be made.

In its terminal portion prior to connection with the portion304, the portion305presents adjacent segments305B and305C that are to form part of the head preform and of the preforms for the head wipers of the blade that is to be made. The segments305B and305C are interlinked only in their central portion in order to provide non-interlinked zones308aand308bthat run in the warp direction all along their upstream and downstream edges and in the weft direction over a limited distance from each of these edges (FIGS. 3 and 4C).

The portion constituting preforms for the head and the head wipers of the blade that is to be made, which is complementary to the portion formed by the segments305B and305C, comes from a segment304A of the portion304situated extending the segments305A and305B of the portion302. During weaving, non-interlinked zones309aand309bare provided in the segment304A all along the segment in the warp direction and over a limited distance from each of its upstream and downstream edges in the weft direction (FIG. 4D). The non-interlinked zones308aand309alie in continuity with each other, as do the non-interlinked zones308band309b. As described below, the non-interlinked zones308a,308b,309a, and309bare used for deploying the preforms for the head wipers of the blade that is to be made.

In the section views4A and4B, arrows indicate the correspondences between the sets of warp yarn layers situated initially in the portions303and306, and subsequently in the portions302and305. In the fiber blank, the total number of warp yarn layers is equal to 18 in this example. The numbers next to braces inFIGS. 4A to 4Dgive an example of how warp yarn layers can be distributed between the various portions of the fiber blank. Thus, in this example, the portion303has four layers, the portion306has 14 layers, and the portion302has eight layers in its lateral portions3021and3022, and ten layers in its central portion3023. Naturally, the total number of warp yarn layers and the way they are distributed could be different, and the numbers given in the example shown are merely for the purpose of facilitating understanding.

FIGS. 5A to 5Dshow weave planes at different levels in the fiber blank300. InFIGS. 5A to 5D, the yarns in section are warp yarns, and it is the platforms of the weft yarns that are shown. In the example shown, the weaving is multilayer or three-dimensional weaving performed using a satin or multi-satin type weave. Other types of multilayer weaving could be used, e.g. multilayer weaving with a multi-plain weave or weaving with an interlock weave. The term “interlock” weave is used herein to mean a weave in which each layer of weft yarns interlinks a plurality of layers of warp yarns with all of the yarns in a given weft column having the same movement in the weave plane. Various kinds of multilayer weaving are described in particular in Document WO 2006/136755.

For the presently-envisaged application to a low pressure turbine blade, the yarns used for weaving are made of refractory material, in particular of ceramic material, such as for example yarns based on silicon carbide (SiC) supplied under the name “Nicalon” by the Japanese supplier Nippon Carbon.

FIG. 5A, which corresponds toFIG. 4A, shows a weave plane of the portions306and3062.

FIG. 5B, which corresponds toFIG. 4B, shows a weave plane of the portions302and305in the vicinity of the connection of the portion302with the portion306, i.e. in the segment305A for the portion305.

FIG. 5C, which corresponds toFIG. 4C, shows a weave plane of the portions302and305in the vicinity of the connection with the portion304, i.e. in the segments305B and305C for the portion305. It can be seen that the segments305B and305C are interlinked in their central portion leaving non-interlinked zones308aand308bin the lateral portions.

In its lateral portions, the portion305presents a number of warp yarn layers that is greater than the number of warp yarn layers in its central portion, with the difference corresponding to the difference between the number of warp yarn layers in the lateral portions of the portion302and the number of warp yarn layers in the central portion of the portion302. All of the warp yarn layers of the portion305are interlinked by weaving. In order to avoid floating too many weft yarns in the thicker portions of the portions302and305, it is possible in certain zones of the fiber blank to take two warp yarns of a given column in two superposed layers of warp yarns and process them as a single warp yarn of double weight. This is shown inFIGS. 5B and 5Cin the thicker portions of the portions302and305.

FIG. 5D, which corresponds toFIG. 4D, shows a weave plane of the portion304in the segment304A. The presence of non-linked zones309aand309bcan be seen.

Advantageously, a row of fiber blanks is woven continuously in the form of a strip3000(FIG. 3), with two adjacent blanks having opposite longitudinal directions. Thus, the portions302and306of the blank300are extended by the portions303′ and306′ of the following blank300′. At the other end of the blank300, the portion304is extended by the portion304″ of the preceding blank300″. Zones of extra length are arranged between adjacent blanks (extra length solely of warp yarns) in order to form transition zones. It should be observed that a plurality of parallel rows of blanks may be woven in a single strip, with zones of extra length then preferably being arranged likewise between parallel rows (extra length solely of weft yarns).

FIGS. 6 to 8are highly diagrammatic and they show how a fiber preform of shape similar to that of the blade that is to be fabricated can be obtained starting from a blank300.

A blank300is cut out from the strip3000by cutting the ends of the portions303and306in planes P1and P2and the end of the portion304in a plane P3. The portion305is cut at the end of the segment305A in a plane P4and at the ends of the segments305B and305C in a plane P5, the fractions of the portion305that extend between the planes P4and P5being eliminated.

The segment303A is deployed along arrow f1ofFIG. 3. The segment305A is deployed along arrow f2ofFIG. 3. The deployed segments205A and205B form a plate313(FIG. 6) that, after molding, is to form the inner platform preform of the blade that is to be fabricated. In the weft direction, the portion305presents a width greater than the width of the portion304, projecting out from either side thereof (see in particularFIGS. 4A and 4B) so as to be capable of forming preform portions corresponding to the upstream and downstream spoilers of the inner platform of the blade that is to be fabricated.

The segments305B and305C that are partially interlinked by weaving are deployed along arrow f3inFIG. 3. The portion304is folded along arrow f4inFIG. 3. The deployed segments305B and305C and the folded portion304form a plate314that is to form the head preform and the head wiper preforms of the blade that is to be fabricated. There can be seen the excess width of the portion305used for forming the upstream and downstream spoiler preforms in the head preform of the blade that is to be fabricated.

Thereafter, as shown inFIG. 7, the portions adjacent to the non-interlinked zones308a-309aand308b-309bon the outside can be deployed so as to form head wiper preforms of the blade that is to be fabricated. The non-interlinked zones308aand309aextend each other so as to form a non-interlinked zone that runs continuously in the warp direction all along the upstream edge of the plate314between two opposite sides of the plate314and over a distance that is limited in the weft direction from the upstream edge of the plate314.

In similar manner, the non-interlinked zones308band309bextend each other to form a non-interlinked zone running continuously in the warp direction all along the downstream edge of the plate314between two opposite sides of the plate314and over a distance that is limited in the warp direction from the downstream edge of the plate314.

A fiber preform320of the blade that is to be fabricated is then obtained by molding the portion302with deformation in order to reproduce the curved profile of the blade airfoil and deforming the plates313and314in order to reproduce shapes similar to those of the inner platform and of the head of the blade, and also so as to confer orientations to the inner platform preform and to the head preform that correspond to the orientations desired for the inner platform and for the head relative to the longitudinal direction in the blade that is to be fabricated, as shown inFIG. 8(where the mold is not shown). This produces the preform310with an airfoil preform320, a root preform360(together with a tang preform), a bottom platform preform330, a head preform platform340, and head wiper preforms352and354.

It should be observed that, advantageously, great freedom is made available for orienting the wiper preforms relative to the head preform. In the blade that is to be fabricated, it is thus possible to obtain any angle that might be desired between each wiper and the outside surface of the head.

In the embodiment ofFIGS. 3 to 8, it is advantageous for the head preform to use layers of yarns coming from the root preform of the blade and that are not used in the airfoil preform of the blade, which layers of yarns are caused to bifurcate between the root preform and the portion of the blade preform that forms the head preform and the head wiper preforms.

In another embodiment, the portion of the fiber blank corresponding to the head preform is made from layers of yarns coming from the portion of the blank corresponding to the airfoil preform, the airfoil preform and the resulting airfoil varying in thickness in the longitudinal direction.

For this other embodiment, it is possible to use a woven fiber blank370as shown diagrammatically inFIGS. 9 and 10A to 10E, the weaving being performed in the form of a fiber strip made up of one or more rows of blanks.

The blank370has a portion372for forming the preform for the airfoil of the blade that is to be made. In the example shown, the portion372is of thickness that does not vary in the transverse direction between the lateral portions corresponding to the leading and trailing edges. Nevertheless, this thickness in the transverse direction could vary as in the portion302of the fiber blank ofFIGS. 3 and 4A to 4D.

The blank370also has a portion376with a segment3761that is to form the preform for the root of the blade that is to be made and a segment3762that is to form the preform of the tang of the blade that is to be made. The portion372is in continuity with the segment3762, with the numbers of layers of warp yarns in the portion372and in the structure3762being equal in this example. Nevertheless, as in the example ofFIGS. 3 and 4A to 4D, it would be possible to have a portion3762of thickness greater than the thickness of the portion372. The segment3761presents thickness greater than the thickness of the stream3762, e.g. obtained by increasing the weight and/or the thread count of the weft yarns or by introducing an insert, as in the example ofFIGS. 3 and 4A to 4D.

The blank also has a portion373that runs along a face376aof the portion376without being interlinked therewith. The warp yarn layers of the portion373cross through the portion372where it connects with the portion376and form a portion375by being woven with one or more layers of warp yarns from the portion372at one or more levels thereof in the longitudinal direction, e.g. the warp yarn layers3721and3722, the thickness of the portion372thus decreasing in the longitudinal direction going from its end connected to the portion376.

The portion375runs along the face372bof the portion372opposite from the face372athat corresponds to the face376aof the portion376. The portion375is not interlinked by weaving with the portion372.

At the end of the portion372remote from its end connected to the portion376, a portion374is formed that extends the portions372and375, uniting their wrap yarn layers by weaving.

A segment373A of the portion373running along the face376aof the portion376and a segment375A of the portion375extending the segment373A and running along the face372bof the portion372are to form the preform for the inner platform of the blade that is to be made.

In its terminal portion prior to connecting with the portion374, the portion375presents adjacent segments375B and375C that are to form a part of the head preform and of the preform for the head wipers of the blade that is to be made. The segments375B and375C are interlinked solely in their central portion in order to provide non-interlinked zones378aand378bthat run in the warp direction all along their upstream and downstream edges and in the weft direction over a limited distance from each of those edges (FIGS. 9 and 10D).

The portion constituting preforms for the head and for the head wipers of the blade that is to be made, which is complementary to the portion formed by the segments375B and375C, comes from a segment374A of the portion374situated extending the segments375A and375B of the portion372. During weaving, non-interlinked zones379aand379bare provided in the segment374A all along it in the warp direction and over a limited distance from each of its upstream and downstream edges in the weft direction (FIG. 4D). The non-interlinked zones378aand379alie in continuity with each other, as do the non-interlinked zones378band379b. The non-interlinked zones378a,378b,379a, and379bare used for deploying the preforms for the head wipers of the blade that is to be made.

It should be observed thatFIGS. 10A, 10B, 10C, 10D, and 10Eare section views on planes A, B, C, D, and E respectively in the segment373A, in the segment375A, in the middle portion of the portion375after connection of the warp yarn layers3721, in the segments375B and375C, and in the segment374A.

After making appropriate cuts, deploying the segments373A,375A, and375B-375C and folding the segment374A, deploying the portions adjacent to the non-interlinked zones, and shaping by molding, a blade preform is obtained having an airfoil preform portion, a root and tang preform portion, a bottom platform preform portion, and a head preform portion together with head wiper preform portions, in a manner similar to that described with reference toFIGS. 6 to 8.

In a variant of the two above-described embodiments, it would also be possible to bring additional yarn layers to the portion of the blank corresponding to the head preform that do not necessarily come from the portion of the blank corresponding to the root or airfoil preforms. Also in a variant, it would also be possible to remove yarn layers from the portion of the blank corresponding to the head preform.

The three different ways described of bringing the warp yarn layers to the portion of the blank corresponding to the head and wiper preform may be implemented separately, or combined in pairs, or all three of them may be combined.

In remarkable manner, a blade fiber preform is obtained in a single piece incorporating the head preform and the wiper preforms, while limiting crossings between fiber blank portions during weaving. This results from making a portion of the blade preform forming a head preform and head wiper preforms by means of a set of yarn layers that are interlinked by weaving while leaving non-interlinked zones that enable the head wiper preforms to be deployed relative to the head preform.

Furthermore, when the blade that is to be fabricated has more than two head wipers, the desired number of head wiper preforms can be obtained by arranging a corresponding number of non-adjacent non-interlinked zones between the upstream and downstream edges of the plate corresponding to the head, such as the plate314ofFIG. 6.

It should be observed that the invention is applicable when the inner platform preform of the blade is made separately with an opening that substantially reproduces the profile of the airfoil of the blade that is to be made. Under such circumstances, a fiber blank is made by weaving without a portion that corresponds to the inner platform preform, i.e. in the embodiment ofFIG. 3, without the portion303. The separately made inner platform preform can then be engaged on the woven fiber blank up to its desired position, prior to deploying the portion of the blade preform that forms the head preform and the head wiper preforms. It would also be possible to fit the outer platform preform at a later stage in fabrication, or to make an outer platform and fit it after fabricating the blade with the airfoil and the outer platform.

Successive steps of a method of fabricating a blade out of ceramic matrix composite (CMC) material are given inFIG. 11.

In a step381, a fiber strip is woven by three-dimensional weaving that comprises a plurality of fiber blanks, as shown inFIG. 3or inFIG. 9, possibly with a plurality of rows of fiber blanks oriented in the warp direction.

In a step382, the individual fiber blanks are cut out.

In a step383, a fiber blank is shaped in a mold, e.g. made of graphite, in order to shape the airfoil preform, the root preform, the inner platform preform, the head preform, and the head wiper preforms (as shown for example inFIGS. 6 to 8), in order to obtain a blade preform.

In a step384, the blade preform is consolidated. In known manner, consolation may be performed by impregnating with a resin that is cured and pyrolized, the quantity of consolidation resin being selected so that the residue of pyrolysis binds together the fibers of the preform sufficiently strongly to enable the preform to be handled while conserving its shape and without any assistance from tooling. It is possible to use a carbon precursor resin or a ceramic precursor resin. The impregnation with the consolidation resin may be performed by infusion or injection into the mold, or by impregnation in the fiber blank stage, prior to shaping. In a variant that is also known, consolidation may be performed by partial densification with a ceramic material using a process known as chemical vapor infiltration (CVI).

The consolidated preform can be extracted from the shaping tooling in order to perform densification with a ceramic matrix, e.g. made of silicon carbide SiC. The densification may be performed by CVI.

The densification may be performed in two successive steps (steps385and387) that are separated by a step386of machining the blade to the desired shapes and dimensions.

It should be observed that pre-machining may be used after consolidation and prior to densification, and in particular pre-machining of the inner platform and of the head in order to eliminate excess thicknesses, and also pre-machining of the head wipers, so as to come close to the blade shape ofFIG. 2.

It should also be observed that an embrittlement relief interphase coating may be formed between the fibers of the preform and the ceramic matrix, in well-known manner.

Embodiment: Compressor Rotor Wheel Blade

The above description relates to a turbine rotor wheel blade made of CMC material.

The invention is also applicable to rotor wheel blades for a gas turbine compressor. Under such circumstances, when the temperatures encountered in operation are lower, in particular for the upstream stages of a compressor, instead of using a CMC material, it is possible for example to use an organic matrix composite (OMC) material made with carbon or glass fibers and a polymer matrix.

Thus, after weaving a set of fiber strips, cutting out individual blanks, and shaping using shaping tooling, a resulting blade preform held in its tooling is impregnated with a resin by injection or infusion. Heat treatment for curing the resin is then performed. A plurality of successive cycles of impregnation with a resin and of curing the resin may be performed. Machining may be performed between two cycles and/or after the end of densification with the polymer matrix. The resin used is a polymer matrix precursor resin, such as an epoxy, bismaleimide, or polyimide resin, for example.

FIGS. 12 and 13A to 13Dare highly diagrammatic and show a first embodiment of a fiber blank400from which it is possible to shape a fiber preform for a blade so that after densifying the preform with a matrix and after optional machining, a composite material blade is obtained incorporating an airfoil, an inner platform, abradable support elements, an outer platform, and mounting hooks, the blade being of the same type as the vane110shown inFIG. 1.

Various weaves may be used for weaving the blank400, e.g. a multi-satin weave similar to that ofFIGS. 5A to 5D, or any other weave as described in particular in above-mentioned Document WO 2006/136755. For the specific application of a turbine nozzle blade, the yarns used for weaving are made of refractory material, in particular of ceramic material, such as for example yarns based on silicon carbide (SiC) as supplied under the name “Nicalon” by the Japanese supplier Nippon Carbon.

The blank400comprises a portion402that is to form the airfoil preform of the blade that is to be made. In the example shown, the portion402is of substantially constant thickness. In a variant, the thickness of the portion402could vary between its longitudinal edges in similar manner to the portion302in the embodiment ofFIG. 3.

The blank400also comprises a portion403with a segment403A running along a first face402aof the portion402without being interlinked with the portion402. The warp yarns of the warp yarn layers of the portion403cross the portion402in order to run along the face402bof the portion402that is opposite from the face402a. The portion403extends along the face402bof the portion402without being interlinked with the portion402, over a distance that corresponds substantially to the longitudinal dimension of the airfoil of the blade that is to be fabricated. Starting from its end remote from its end situated at the crossing by the portion403, the portion402is united with the portion403by weaving in order to form a portion404.

The segment403A of the portion403running along the face402aof the portion402, and a segment403B of the portion403extending the segment403A, after crossing through the portion402, are for forming the preform for the inner platform and the preforms for the abradable support elements of the blade that is to be made. Non-interlinked zones403aand403bare provided substantially at half-thickness in the segments403A and403B, the non-interlinked zone403arunning in the warp direction all along the upstream edges of the segments403A and403B, and in the weft direction over a limited distance from each of these upstream edges, and the non-interlinked zone403brunning in the warp direction all along the downstream edges of the segments403A and403B and in the weft direction over a limited distance from each of these downstream edges (FIGS. 12, 13A, and 13B). As described below, the non-interlinked zones403aand403bserve to make it possible to deploy preforms for abradable support elements of the blade that is to be made.

In its terminal portion prior to connection with the portion404, the portion403presents a segment403C that is to form a portion of the outer platform preform and of mounting hook preforms of the blade that is to be made. Non-interlinked zones403cand403dare provided substantially at half-thickness in the segment403C, the non-interlinked zone403crunning in the warp direction all along the upstream edge of the segment403C and in the weft direction over a limited distance from the upstream edge, and the non-interlinked zone403drunning in the warp direction all along the downstream edge of the segment403C and in the weft direction over a limited distance from the downstream edge (FIGS. 12 and 13C).

The portion for the outer platform preform and the mounting hook preforms of the blade that is to be made, which is complementary to the portion by the segment403C, comes from a segment404A of the portion404. During weaving, non-interlinked zones404aand404bare provided in the segment404A all along it in the warp direction and over a limited distance from each of its upstream and downstream edges in the weft direction (FIGS. 12 and 13D). The non-interlinked zones403cand404aare in continuity with each other, as are the non-interlinked zones403dand404b. As described below, the non-interlinked zones403c,403d,404a, and404bserve to make it possible to deploy the mounting hook preforms of the blade that is to be made.

Advantageously, a row of fiber blanks is woven continuously in the form of a strip4000(FIG. 12), with two adjacent blanks having opposite longitudinal directions. Thus, the portions402and403of the blank400are extended by the portions402′ and403′ of the following blank400′. At the other end of the blank400, the portion404is extended by the portion404″ of the preceding blank400″. Zones of extra length are arranged between adjacent blanks (extra length solely of warp yarns) in order to form transition zones. It should be observed that a plurality of parallel rows of blanks may be woven in a single strip, with zones of extra length then preferably being provided also between parallel rows (extra length solely of weft yarns).

FIGS. 12 and 14 to 16are highly diagrammatic and they show how a fiber preform of a shape similar to that of the blade that is to be fabricated can be obtained from a blank400.

A blank400is cut out from the strip4000by cutting the portion403at the ends of the segments403A and403B in planes P1and P2and by cutting the portion402in a plane P3situated in front of the location of the crossing by the portion403. The portion404is cut at the end of the segment404A in a plane P4. The segment403C is cut in a plane P5, the fractions of the portion403running between the planes P2and P5being eliminated.

The segments403A and403B are deployed along arrows f1and f2inFIG. 12. As shown inFIG. 14, the portions of the segments403A and403B situated on the outside form a plate413that, after molding, is to form the inner platform preform, while the portions of the segments403A and403B adjacent to the non-interlinked zones403aand403b, on the inside can be deployed to be able to form preforms for the abradable support elements of the blade that is to be fabricated.

The segment403C is deployed along arrow f3inFIG. 12. The segment404A is folded along arrow f4ofFIG. 12. The deployed segment403C and the folded segment404form a plate414that is to form the preform for the outer platform and the preforms for the mounting hooks of the blade that is to be fabricated.

Thereafter, as shown inFIG. 15, the portions adjacent to the non-interlinked zones403c,403d,404a, and404b, on the outside, can be deployed so as to form mounting hook preforms for the blade that is to be fabricated. The non-interlinked zones403cand404aextend each other to form a non-interlinked zone running continuously in the warp direction all along the upstream edge of the plate414between two opposite sides of the plate414, and over a limited distance in the weft direction from the upstream edge of the plate414. In similar manner, the non-interlinked zones403dand404bextend each other to form a non-interlinked zone extending continuously in the warp direction all along the downstream edge of the plate414, between two opposite sides of the plate414, and over a limited distance in the weft direction from the downstream edge of the plate414.

A fiber preform410of the blade that is to be fabricated is then obtained by molding in order to obtain the curved profile of the airfoil of the blade, shapes that are similar to those of the inner and outer platforms of the blade, orientations of the preforms of the inner and outer platforms that correspond to the desired orientations for the inner and outer platforms relative to the longitudinal direction in the blade that is to be fabricated, and also shapes corresponding to the shapes of the support elements and the mounting hooks, as shown inFIG. 16(the mold not being shown). The preform410is thus obtained comprising an airfoil preform420, an inner platform preform430, preforms462and464for abradable support elements, an outer platform preform440, and mounting hook preforms452and454.

FIGS. 17 and 18A to 18Dare highly diagrammatic, showing a second embodiment of a fiber blank500from which it is possible to shape a fiber preform for a blade so that after densifying the preform with a matrix and after optional machining, a composite material blade is obtained incorporating an airfoil, an inner platform, abradable support elements, an outer platform, and mounting hooks, the blade being of the same type as the vane110shown inFIG. 1.

The fiber blank500differs from the fiber blank400in that it is substantially symmetrical about a middle transverse plane, the portion of the blank corresponding to the inner platform preform and the abradable supports being of a configuration similar to the configuration of the portion of the blank corresponding to the outer platform preform and the mounting hooks.

Thus, the blank500has a portion502that is to form the preform for the airfoil of the blade that is to be made. In the example shown, the portion502is of thickness that is substantially constant. In a variant, the thickness of the portion502could vary between its longitudinal edges in similar manner to the portion302in the embodiment ofFIG. 3.

The blank500also comprises a portion503that runs along a face502bof the portion502without being linked thereto by weaving. At the longitudinal ends of the portion502, the yarn layers of the portions502and503are united by weaving in order to form portions504and505.

A segment505A of the portion505and a segment503A of the portion503that connects with the segment505A are for forming a preform for the inner platform and preforms for the abradable supports of the blade that is to be made. Non-interlinked zones505a,505b, and503a,503bare provided substantially at half-thickness in the segments505A and503A, the non-interlinked zones505aand503arunning in the warp direction all along the upstream edges of the segments505A and503A and in the weft direction over a limited distance from each of these upstream edges, and the non-interlinked zones505band503brunning in the warp direction all along the downstream edges of the segments505A and503A and in the weft direction over a limited distance from each of these downstream edges (FIGS. 17, 18A, and 18B). The non-interlinked zones505a,503a,505b, and503bserve to make it possible to deploy preforms for the abradable support elements of the blade that is to be made.

A segment504A of the portion504and a segment503B of the portion503that connects with the segment505A are for forming an outer platform preform and mounting hook preforms of the blade that is to be made. Non-interlinked zones503c,504a, and503d,504bare provided substantially at half-thickness in the segments503B and504A, the non-interlinked zones503cand504arunning in the warp direction all along the upstream edges of the segments503B and504A and in the weft direction over a limited distance from these upstream edges, and the non-interlinked zones503dand504bextending in the warp direction all along the downstream edges of the segments503B and504A and in the weft direction over a limited distance from the downstream edges (FIGS. 17, 18C, and18D). The non-interlinked zones503c,504a,503d, and504bserve to make it possible to deploy the mounting hook preforms of the blade that is to be made.

Advantageously, at least one row of fiber blanks500is woven continuously in the form of a strip5000(FIG. 17).

FIGS. 17 and 19 to 21are highly diagrammatic, showing how a fiber preform having a shape close to that of the blade that is to be fabricated can be obtained from the blank500.

A blank500is cut out from the strip5000by cutting the portions505and504in planes P1and P4and by cutting the portion503in planes P2and P5, the fractions of the portion503that run between the planes P2and P5being eliminated.

The segments505A and503A are deployed along arrows f1and f2inFIG. 17and they form a plate513(FIG. 19) that, after molding, is to form the inner platform preform and the preforms of abradable support elements of the blade that is to be fabricated. The non-interlinked zones505aand503aextend each other to form a non-interlinked zone running continuously in the warp direction all along the upstream edge of the plate513between two opposite sides of the plate513, and over a limited distance in the weft direction from the upstream edge of the plate513. The non-interlinked zones505band503bextend each other to form a non-interlinked zone running continuously in the warp direction all along the downstream edge of the plate513between two opposite sides of the plate513, and over a limited distance in the weft direction from the downstream edge of the plate513.

The segments503B and504A are deployed along arrows f3and f4inFIG. 17and they form a plate514(FIG. 19) that is to form the preform for the outer platform and the preforms for the mounting hooks of the blade that is to be fabricated. The non-interlinked zones503cand504aextend each other to form a non-interlinked zone running continuously in the warp direction all along the downstream edge of the plate514between two opposite sides of the plate514, and over a limited distance in the weft direction from the upstream edge of the plate514. The non-interlinked zones503dand504bextend each other to form a non-interlinked zone running continuously in the warp direction all along the downstream edge of the plate514between two opposite sides of the plate514, and over a limited distance in the weft direction from the downstream edge of the plate514.

Thereafter, as shown inFIG. 20, the portions adjacent to the non-interlinked zones505a,503a,505b, and503b, on the inside, are deployed so as to form preforms for abradable support elements of the blade that is to be fabricated, while the portions adjacent to the non-interlinked zones503c,503d,504a, and504b, on the outside, are deployed so as to form preforms for the mounting hooks of the blade that is to be fabricated.

A fiber preform510of the blade that is to be fabricated is then obtained by molding in order to obtain the curved profile of the airfoil of the blade, shapes similar to the shapes of the inner and outer platforms of the blade, orientations of the inner and outer platform preforms corresponding to the orientations desired for the inner and outer platforms relative to the longitudinal direction of the blade that is to be fabricated, and shapes corresponding to the shapes of the support elements and of the mounting hooks, as shown inFIG. 21(the mold not being shown). The preform510is thus obtained comprising an airfoil preform520, an inner platform preform530, preforms562and564for abradable support elements, an outer platform preform540, and preforms552,554for mounting hooks.

In remarkable manner, in both of the above-described embodiments, a blade fiber preform is obtained as a single piece incorporating inner and outer platform preforms, abradable support element preforms, and mounting hook preforms, while limiting crossings between portions of the fiber blank during weaving. This results from making a blade preform portion that forms a platform preform and support element preforms or mounting hook preforms by means of a set of yarn layers that are interlinked by weaving, with non-interlinked zones being provided so as to make it possible to deploy support element preforms or mounting hook preforms relative to the platform preforms.

Naturally, it is possible to make abradable support elements of shapes other than the L-shaped profile elements162and164.

Thus,FIG. 22shows support elements162′ and164′ that project substantially radially from the outside face of the inner platform130and on which it is possible to fasten an intermediate support165carrying blocks166′ of abradable material upstream and downstream in order to co-operate with the wipers of rotor wheels that are adjacent to the nozzle on the upstream and downstream sides.

It is also possible to envisage having a single abradable support element projecting from the central portion of the outside face of the inner platform.

In order to obtain a turbine nozzle blade made out of CMC from a woven fiber blank, it is possible to proceed as described above with reference toFIG. 11.

Embodiment: Compressor Guide Vane Blade

The description above relates to making a turbine nozzle blade out of CMC material.

The invention is also applicable in the same manner to making CMC material guide vane blades for a gas turbine compressor.

When the temperatures encountered in service are lower, in particular for the upstream stages of a compressor, it is possible to use guide vane blades that are not made of CMC material, but that are made of organic matrix composite (OMC) material, made using carbon or glass fibers with a polymer matrix.

In order to obtain a compressor guide vane blade made of OMC from a woven fiber blank, it is possible to proceed as described above for a compressor rotor wheel blade made of OMC.

The method described for the two last-described embodiments makes it possible to obtain a blade incorporating an airfoil, an outer platform, mounting hooks, an inner platform, and abradable support elements.

Nevertheless, the method is also applicable to making a blade incorporating an airfoil, an outer platform, mounting hooks, and an inner platform but without incorporating abradable support elements, and indeed to making a blade incorporating an airfoil, an outer platform, an inner platform, and at least one abradable support element, but without incorporating mounting hooks.

Variant Embodiments

In the embodiments described of a turbine nozzle blade, the preform for the blade airfoil presents thickness that is constant in the longitudinal direction. In a variant, this thickness could be made to vary in the same manner as that described with reference toFIGS. 9 and 10A to 10Efor a turbine rotor wheel blade. The same applies for a compressor rotor wheel blade and for a compressor guide vane blade.

In the embodiments ofFIGS. 3, 9, and 12, the longitudinal direction of the fiber blank in the woven strip may be reversed.

In the turbine nozzle embodiments that are described, the mounting hooks are associated with the outer platform and the abradable support element(s) is/are associated with the inner platform. In a variant, it is possible to associate the mounting hooks with the inner platform and one or more abradable support elements with the outer platform.

Above, the fiber blanks are described as being woven with the warp direction corresponding to their longitudinal direction. In a variant, the weaving could be performed with the longitudinal direction of the fiber blanks corresponding to the weft direction, with weft and warp then being interchanged.