Turbine component having a connecting edge made of a composite material having a ceramic matrix and short fibers and method for producing the same

Abstract

A turbine component (10) of an annular assembly comprises a structural body (11) and a connecting edge (12) integral with the structural body. Each connecting edge comprises at least one groove (120, 121) for receiving a sealing tab (30, 31). Each connecting edge (12) is made of a composite material comprising fiber reinforcement consisting of randomly oriented short fibers, the reinforcement being densified by a ceramic matrix.

Description

Technical Field

[0001] The invention relates to turbine or gas turbine components between which a seal must be produced by means of at least one sealing web which is accommodated in a groove present on the connecting edges of adjacent components.

[0002] For example, the present invention relates, but not exclusively, to a turbine ring assembly for a turbine, the assembly comprising a plurality of ring segments made of a ceramic matrix composite material or of a metallic material and a ring support structure. The seal between adjacent ring segments is established by one or more sealing tabs housed in grooves machined into the connecting edges of the segments.

[0003] The ring segments can be made of metallic material. Due to the high temperatures encountered by the rings during operation, hot spots are located in the sealing areas created by the webs between the ring segments. Therefore, in this case, it is necessary to provide dedicated cooling ventilation, which is relatively detrimental to the performance of the turbine.

[0004] Ceramic matrix composites, or CMCs, are known for their good mechanical properties, which make them suitable for forming structural elements, and for their ability to maintain these properties at high temperatures. CMCs have been envisioned for use in various hot parts of aerospace engines, particularly because their density is less than that of conventionally used refractory metals.

[0005] In particular, WO 2017 / 060604 describes the manufacture of turbine ring assemblies from CMC ring segments, which are reinforced with fibers obtained by three-dimensional weaving (3D) densified from a ceramic matrix. For metal ring segments, the seal between adjacent ring segments is created by one or more sealing tabs housed in grooves machined into the connecting edges of the segments.

[0006] While the use of CMC ring segments makes it possible to significantly reduce, or even eliminate, the ventilation required for cooling the turbine ring, machining CMC materials, including 3D woven fiber reinforcement, is difficult. This becomes even more difficult when such machining must be performed with high precision on relatively large dimensions, such as for the relatively deep and fine grooves mentioned above.

[0007] These disadvantages also exist in other segmented turbine assemblies in which the seal between the components is produced by sealing tabs received in grooves.

[0008] Therefore, there is a need to easily create seals between components of a segmented assembly without having to cool the seal area. Summary of the Invention

[0009] To this end, the present invention proposes a turbine component in the form of an annular assembly extending about an axis, comprising a structural body and at least one connecting edge integral with the structural body, each connecting edge having at least one recess for receiving a sealing tab, characterized in that each connecting edge is made of a composite material comprising fiber reinforcement consisting of randomly oriented short fibers, the reinforcement being densified by a ceramic matrix. In this context, "structure" shall refer to the body's ability to support mechanical loads and / or transmit these forces.

[0010] By providing turbine components with one or more connecting edges made of a ceramic matrix composite (a material capable of withstanding high temperatures), the need for cooling ventilation in one or more sealing areas between the components is significantly reduced or even eliminated. Furthermore, the connecting edge or edges are made of a ceramic matrix composite with short-fiber reinforcement, a material that is easier to machine and more easily allows for the creation of fine, deep grooves. This ensures greater dimensional control and, therefore, greater sealing reliability.

[0011] According to a particular aspect of the turbine component of the present invention, the structural body is made of a composite material comprising fiber reinforcement consisting of multiple yarn layers connected by a three-dimensional or multi-layer braid, the reinforcement being densified by a ceramic matrix. In this case, the component benefits from the advantages of the CMC material as a whole (reduced overall mass, good thermal resistance), while facilitating the manufacture of the grooves for sealing the joints and controlling the dimensions of said grooves.

[0012] According to another particular aspect of the turbine component according to the present invention, the structural body is made of a metallic material. Thus, due to the metallic structural body, a component having good mechanical strength is obtained, while the need for cooling in its sealing area is eliminated due to the connection edge made of ceramic matrix composite material and short fibers.

[0013] According to a particular feature of the turbine component of the invention, the component is a turbine ring segment extending in an annular manner around an axis, the segment comprising a segment structural body having an annular base having an inner surface and an outer surface, the inner surface being intended to define the inner surface of the turbine ring when the ring segment is mounted on a ring support structure, one or more attachment portions of the ring segment extending from the outer surface to the ring support structure, the ring segment further comprising two inter-segment connecting edges at the circumferential ends of the segment structural body, each inter-segment connecting edge being intended to be opposite to a circumferentially adjacent ring segment when the ring segment is mounted on the ring support structure, each inter-segment connecting edge having one or more grooves intended to receive a sealing tab.

[0014] According to another particular feature of the turbine component according to the invention, the component is a nozzle segment extending in an annular manner around an axis, the segment comprising a segment structural body having an aerodynamic profile extending in the radial direction between the inner platform and the outer platform and in the axial direction between the leading edge and the trailing edge, the segment further comprising two inter-platform connecting edges present at the circumferential ends of each platform, each inter-platform connecting edge being intended to be opposite to the platform of an adjacent segment, each inter-platform connecting edge having one or more grooves intended to receive a sealing tab.

[0015] According to another particular feature of the turbine component according to the invention, the component is a turbine blade extending in an annular manner around an axis, the blade comprising a blade structural body extending in a radial direction between a root portion or inner portion and a blade tip or outer portion and in an axial direction between a leading edge and a trailing edge, said body further comprising at least one platform, the turbine blade further comprising two inter-platform connecting edges at the circumferential ends of each platform, each inter-platform connecting edge being intended to be opposite to a platform of an adjacent blade, each inter-platform connecting edge having one or more grooves intended to receive a sealing tab.

[0016] The invention also relates to a method for manufacturing a turbine component of an annular assembly extending about an axis, the method comprising:

[0017] -Manufacture the structural body,

[0018] - manufacturing at least one connecting edge integral with a structural body made of composite material comprising a fiber reinforcement consisting of randomly oriented short fibers, said reinforcement being densified by a ceramic matrix, each connecting edge having at least one groove for receiving a sealing joint,

[0019] -Securing each connecting edge to the structural body.

[0020] One or more connecting edges made of ceramic matrix composite material with short fiber reinforcement can easily achieve fine and deep grooves without the difficulty of machining and with greater dimensional control. By providing turbine components with one or more connecting edges made of ceramic matrix composite material (a material capable of withstanding high temperatures), the need for cooling ventilation of one or more sealing areas between the components is significantly reduced or even eliminated.

[0021] According to a particular aspect of the method according to the invention, the production of the structural body comprises three-dimensional or multilayer braiding of fiber reinforcement, and densification of the fiber reinforcement by means of a ceramic matrix. In this case, the component benefits from the overall advantages of the CMC material (good thermal resistance with reduced overall mass), while facilitating the production of the grooves for sealing the joints and controlling the dimensions of said grooves. In this case, each connecting edge is fixed to the structural body by brazing, mechanical joining, or co-siliconization.

[0022] According to a particular aspect of the method according to the present invention, the structural body is made of a metallic material. Thus, the metallic structural body provides a component with good mechanical strength, while the joining edges, made of ceramic matrix composite and short fibers, eliminate the need for cooling in their sealing areas. In this case, each joining edge is secured to the structural body by brazing or mechanical connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A is a schematic exploded perspective view of two turbine components corresponding to portions of a segmented flow path according to an embodiment of the present invention;

[0024] Figure 1 B is once assembled Figure 1 A schematic perspective view of the two components of A;

[0025] Figure 2 A is a schematic exploded perspective view of a turbine ring segment according to an embodiment of the present invention;

[0026] Figure 2 B is once assembled Figure 2 A schematic perspective view of a ring segment of A;

[0027] Figure 3 A is a schematic exploded perspective view of a turbine ring segment according to an embodiment of the present invention;

[0028] Figure 3 B is once assembled Figure 3 A schematic perspective view of a ring segment of A;

[0029] Figure 4 is a schematic perspective view of a stator segment according to an embodiment of the present invention; and

[0030] Figure 5 is a schematic perspective view of a runner blade according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention generally relates to any turbine or gas turbine component intended to produce a seal with an adjacent component by means of at least one sealing tab, which is received in a groove present in one or more connecting edges of the adjacent component. The component according to the invention corresponds to a component for forming an annular assembly of a turbine, such as a turbine ring, a nozzle, a turbine runner, etc.

[0032] Figure 1 A and 1B show two turbine components 10 and 20 corresponding to portions of a segmented flow path extending in an annular manner around the axis X. Figure 1 In A and 1B, the components 10 and 20 each include a structural body 11, 21 made of a metal material or a ceramic matrix composite (CMC) and a connecting edge 12, 22. Figure 1 In A and 1B, for simplicity, only the connecting edges 12 and 22 of the components 10 and 20 are shown. The components 10 and 20 each include another connecting edge at their axially opposite ends so as to connect with the axially adjacent turbine components ( Figure 1 A and 1B) create a seal.

[0033] According to the present invention, the connecting edges 12 and 22 are made of a composite material comprising a fiber reinforcement consisting of randomly oriented short fibers densified by a ceramic matrix. The connecting edge 12 has a first groove 120 for receiving a portion of the first sealing tab 30 and a second groove 121 for receiving a portion of the second sealing tab 31. The connecting edge 22 has a first groove 220 for receiving another portion of the first sealing tab 30 and a second groove 221 for receiving another portion of the second sealing tab 31.

[0034] Figure 2 2A and 2B show a turbine component corresponding to a turbine ring segment 40 extending in an annular manner around the axis X. The ring segment 40 has a substantially inverted π-shaped cross section with an annular base 44, the inner surface of which defines the gas flow path in the turbine ( Figure 2 B). Upstream and downstream legs 45, 46 extend from the outer surface of the annular base 12 and are intended to be fixed to the Figure 2 A and 2B are on an annular flange of a ring support structure not shown. Ring segment 40 is one segment from a plurality of ring segments which together form a turbine ring, creating a seal between adjacent ring segments at all circumferences of the ring.

[0035] The turbine ring segment 40 comprises a structural body 41 made of ceramic matrix composite (CMC) and two inter-segment connecting edges 42 and 43 respectively present at circumferential ends 41 a and 41 b of the structural body 41 .

[0036] According to the present invention, the inter-segment connecting edges 42 and 43 are made of a composite material including a fiber reinforcement consisting of randomly oriented short fibers densified by a ceramic matrix. The connecting edge 42 has a first groove 420 for receiving a portion of the first sealing tab 50, a second groove 421 for receiving a portion of the second sealing tab 51, and a third groove 422 for receiving a portion of the third sealing tab 52. The connecting edge 43 also has three grooves ( Figure 2 A and 2B), grooves 420, 421 and 422 similar to the inter-segment connecting edge 42 receive a portion of the fourth sealing web 53, a portion of the fifth sealing web 54 and a portion of the sixth sealing web 55, respectively.

[0037] Figure 3 A and 3B show a turbine component corresponding to a turbine ring segment 60 extending in an annular manner around the axis X. The ring segment 60 has an annular base 64, the inner surface of which defines the flow path of the gas flow in the turbine ( Figure 3 B) Ring segment 60 is one segment from a plurality of ring segments which together comprise a turbine ring, creating a seal between adjacent ring segments at all circumferences of the ring.

[0038] The turbine ring segment 60 includes a segment structural body 61 made of a metal material and two inter-segment connecting edges 62 and 63 respectively present at circumferential ends 61 a and 61 b of the structural body 61 .

[0039] According to the present invention, the inter-segment connecting edges 62 and 63 are made of a composite material including fiber reinforcement consisting of randomly oriented short fibers densified by a ceramic matrix. The connecting edge 62 has a first groove 620 for receiving a portion of the first sealing tab 70, a second groove 621 for receiving a portion of the second sealing tab 71, and a third groove 622 for receiving a portion of the third sealing tab 72. The connecting edge 63 also has three grooves ( Figure 3 A and 3B), similar to the grooves 620, 621 and 622 of the inter-segment connecting edge 62, these grooves receive a portion of the fourth sealing web 73, a portion of the fifth sealing web 74 and a portion of the sixth sealing web 75, respectively.

[0040] Figure 4 A turbine component corresponding to a turbine nozzle segment 80 is shown, which extends in an annular manner around the axis X. The nozzle segment 80 has a segment structural body 81 made of CMC material, which includes a radial direction D between an inner platform 83 and an outer platform 84. R and in the axial direction D between the leading edge 82a and the trailing edge 82b. AThe aerodynamic profile 82 extends upward. The nozzle segment 80 is one segment from a plurality of nozzle segments that together form a turbine nozzle, creating a seal between all circumferentially adjacent nozzle segments of the nozzle.

[0041] The turbine ring segment 80 further includes two inter-platform connecting edges 830 and 831 at the inner platform 83, which are respectively present at the circumferential ends 83a and 83b of the inner platform 83. Similarly, the turbine ring segment 80 includes two inter-platform connecting edges 840 and 841 at the outer platform 84, which are respectively present at the circumferential ends 84a and 84b of the outer platform 84.

[0042] According to the present invention, the inter-platform connecting edges 830, 831, 840, and 841 are made of a composite material that includes fiber reinforcement consisting of randomly oriented short fibers that are densified by a ceramic matrix. Connecting edges 830 and 831 have a groove 8300 and a groove 8310, respectively, with groove 8300 receiving a portion of the first sealing tab 90 and groove 8310 receiving a portion of the second sealing tab 91. Connecting edge 840 has two grooves 8400 and 8401, which receive portions of the third and fourth sealing tabs 92 and 93, respectively. Connecting edge 841 also has two grooves 8410 and 8411, which receive portions of the fourth sealing tab 94 and a portion of the fifth sealing tab 95, respectively.

[0043] Figure 5 A turbine component is shown which corresponds to a turbine blade 100 extending in an annular manner around an axis X. The blade 100 has a blade structural body 110 made of CMC material which is arranged in a radial direction D between a root portion or inner portion 111 and a blade tip or outer portion 112. R and the axial direction D between the leading edge 110a and the trailing edge 110b A Extension. In the embodiment described here, the blade 100 further comprises an inner platform 130. The blade 100 is intended to be fixed to the hub ( Figure 5 The blade 100 is one of a plurality of blades fixed to the hub and together forming a turbine wheel or rotor, creating a seal between adjacent blades at all circumferences of the wheel.

[0044] The blade 100 further comprises, at the inner platform 130 , two inter-platform connecting edges 131 and 132 , respectively present at the circumferential ends 130 a and 130 b of the inner platform 130 .

[0045] According to the invention, the inter-platform connecting edges 131 and 132 are made of a composite material comprising a fiber reinforcement consisting of randomly oriented short fibers densified by a ceramic matrix. The connecting edges 131 and 132 have, respectively, a groove 1310 and a groove 1320, the groove 1310 receiving a portion of the first sealing tab 140 and the groove 1320 receiving a portion of the second sealing tab 141, thereby creating a seal in the turbine gas circulation flow path defined by the confluence of the inner platforms of the blade.

[0046] As mentioned above, the turbine component according to the present invention comprises a structural body, which may be made of a metallic material or a ceramic matrix composite material.

[0047] When a structural body is made of a ceramic matrix composite, the components made of CMC material are formed by fiber reinforcement made of refractory fibers (carbon or ceramic), which are densified by a ceramic matrix (especially carbide, nitride, refracting oxide, etc.). Typical embodiments of CMC materials are C-SiC (reinforcement made of carbon fiber and silicon carbide matrix), SiC-SiC material and CC / SiC material (mixed carbon / silicon carbide matrix). The manufacture of components made of CMC composite materials is well known. Fiber reinforcement is preferably directly manufactured into a single piece by three-dimensional weaving (3D). Here, "three-dimensional weaving" or "3D weaving" or "multi-layer weaving" should mean a weaving method by which, by weaving corresponding to the weaving type, at least some weft yarns are connected to warp yarns on several layers of warp yarns, or vice versa, and the weaving type can be particularly selected from the following weavings: interlock, multi-canvas, multi-satin and multi-twill. 3D reinforcement makes it possible to obtain complex geometric shapes with very high anti-delamination capabilities.

[0048] The sealing web can be manufactured from a nickel-based and / or cobalt-based alloy.

[0049] An embodiment of the production of a ceramic matrix composite material with a short fiber-reinforced joining edge begins with a supply of short fibers, which can be obtained by mechanical grinding, energy milling, or by cutting long fibers, and then screening fibers that meet a length specification between 10 μm and 1000 μm. This is followed by the deposition of a mesophase corresponding to the formation of a mesophase layer around the short fibers, so as not to weaken the final material. The mesophase deposit can be produced by chemical vapor deposition (CVD) in a fluidized bed. The short fibers coated with the mesophase are then mixed with a ceramic particle powder, such as silicon carbide particles, and an organic binder comprising at least one polymer, such as a thermoplastic polymer selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), polypropylene (PP), polyoxymethylene (POM), polyethylene terephthalate (PET), or a thermosetting polymer selected from the group consisting of epoxy resins, phenolic resins, and pre-ceramic resins.

[0050] The mixture is injected into a mold having the shape of the finished component or an intermediate shape of the finished shape of the finished component. The organic binder is then polymerized. The solidified component, corresponding to the green body, is then demolded. The following steps involve infiltrating the green body with a molten silicon-based composition (siliconization) to form a ceramic matrix, through a densification method known by the process name MI ("melt infiltration"), which corresponds to the colonization of the residual porosity of the debindered material by the capillary rise of molten metal (e.g. silicon).

[0051] In particular, examples of the production of components made of ceramic matrix composite materials with short fibers are disclosed in documents WO 2019 / 122760 and WO 2019 / 122758.

[0052] If necessary, machining can be performed by machining the densified component to obtain the final geometry.

[0053] In this way, a connecting edge is obtained comprising short fibers having a length between 10 μm and 1000 μm and covered with a mesophase, the fibers being oriented and distributed in a random manner within a matrix of silicon and silicon carbide. The manufacture of the connecting edge does not involve a braiding operation.

[0054] When the structural body is made of a composite material comprising a 3D woven or multi-layer woven fiber reinforcement densified by a ceramic matrix, the one or more connecting edges may be made in one piece with the structural body or manufactured separately and then attached to the structural body.

[0055] In the first case, a preform of a structural body in a consolidated state (i.e., a 3D braided or multi-layer braided fiber reinforcement formed and consolidated by deposition of an interphase as described above) is placed in a mold or holding tool with one or more green connecting edges in contact with one or more circumferential ends of the preform of the structural body. The assembly then undergoes co-siliconization, allowing the one or more connecting edges to be fixed to the structural body and the final turbine component to be obtained.

[0056] In case the structural body and the connecting edge(s) are manufactured separately, the connecting edge(s) may be fixed to the structural body by brazing or mechanical connection (bolting, clamping, interlocking, etc.).

[0057] When the structural body is made of a metallic material, the connection edge or edges may be manufactured separately and then fixed to the structural body by brazing or mechanical connection (bolting, clamping, interlocking, etc.).

Claims

1. A turbine component of an annular assembly extending about an axis, the component comprising a structural body and at least one connecting edge, each connecting edge having at least one groove for receiving a sealing tab, wherein: Each connecting edge is made of a composite material comprising fiber reinforcement consisting of randomly oriented short fibers, the reinforcement being densified by a ceramic matrix, wherein the structural body is made of a material different from the composite material comprising fiber reinforcement consisting of randomly oriented short fibers than the at least one connecting edge, and the at least one connecting edge is fixed to the structural body, wherein the component is a turbine ring segment extending in an annular manner around an axis, the segment comprising a segment structural body having an annular base having an inner surface and an outer surface, the inner surface being intended to define an inner surface of the turbine ring when the ring segment is mounted on a ring support structure, one or more attachment portions of the ring segment extending from the outer surface to the ring support structure, the ring segment further comprising two inter-segment connecting edges at the circumferential ends of the segment structural body, each inter-segment connecting edge being intended to be opposite a circumferentially adjacent ring segment when the ring segment is mounted on the annular support structure, each inter-segment connecting edge having one or more grooves, each groove being intended to receive a sealing tab.

2. The component according to claim 1, wherein The structural body is made of a composite material comprising a fiber reinforcement consisting of multiple layers of yarns connected together by a three-dimensional or multilayer braiding, the reinforcement being densified by a ceramic matrix.

3. The component according to claim 1, wherein The structural body is made of metal material.

4. A turbine component of an annular assembly extending about an axis, the component comprising a structural body and at least one connecting edge, each connecting edge having at least one groove for receiving a sealing tab, wherein: Each connecting edge is made of a composite material comprising a fiber reinforcement consisting of randomly oriented short fibers, the reinforcement being densified by a ceramic matrix, wherein the structural body is made of a material different from the composite material comprising fiber reinforcement consisting of randomly oriented short fibers of the at least one connecting edge, and the at least one connecting edge is fixed to the structural body, wherein the component is a nozzle segment extending in an annular manner around an axis, the segment comprising a segment structural body having an aerodynamic profile extending in a radial direction between an inner platform and an outer platform and in an axial direction between a leading edge and a trailing edge, the segment further comprising two inter-platform connecting edges present at the circumferential ends of each platform, each inter-platform connecting edge being intended to be opposite to a platform of a circumferentially adjacent segment, each inter-platform connecting edge having one or more grooves, each groove being intended to receive a sealing tab.

5. A turbine component of an annular assembly extending about an axis, the component comprising a structural body and at least one connecting edge, each connecting edge having at least one groove for receiving a sealing tab, wherein: Each connecting edge is made of a composite material comprising fiber reinforcement consisting of randomly oriented short fibers, said reinforcement being densified by a ceramic matrix, wherein the structural body is made of a material different from the composite material comprising fiber reinforcement consisting of randomly oriented short fibers than said at least one connecting edge, and said at least one connecting edge is fixed to the structural body, wherein the component is a turbine blade extending in an annular manner around an axis, said blade comprising a blade structural body extending in a radial direction between a root portion or inner portion and a blade tip or outer portion and in an axial direction between a leading edge and a trailing edge, said body further comprising at least one platform, the turbine blade further comprising two inter-platform connecting edges at the circumferential end of each platform, each inter-platform connecting edge being intended to be opposite to a platform of a circumferentially adjacent blade, each inter-platform connecting edge having one or more grooves intended to receive a sealing joint.

6. A method for manufacturing a turbine component of an annular assembly extending about an axis, the component comprising a structural body and at least one connecting edge, each connecting edge having at least one groove for receiving a sealing tab, wherein: Each connecting edge is made of a composite material comprising fiber reinforcement consisting of randomly oriented short fibers, said reinforcement being densified by a ceramic matrix, wherein the structural body is made of a material different from the composite material comprising fiber reinforcement consisting of randomly oriented short fibers from said at least one connecting edge, and said at least one connecting edge is fixed to the structural body, wherein the component is a turbine ring segment extending in an annular manner about an axis, the segment comprising a segment structural body having an annular base having an inner surface and an outer surface, the inner surface being intended to define an inner surface of the turbine ring when the ring segment is mounted on a ring support structure, one or more attachment portions of the ring segment extending from the outer surface to the ring support structure, the ring segment further comprising two inter-segment connecting edges at circumferential ends of the segment structural body, each inter-segment connecting edge being intended to be opposite a circumferentially adjacent ring segment when the ring segment is mounted on the annular support structure, each inter-segment connecting edge having one or more grooves, each groove being intended to receive a sealing tab, the method comprising: -Manufacture the structural body, - producing at least one connecting edge made of a composite material comprising a fiber reinforcement consisting of randomly oriented short fibers, said reinforcement being densified by a ceramic matrix, each connecting edge having at least one groove for receiving a sealing tab, - fixing each connecting edge to a structural body, wherein said structural body is made of a material different from the composite material of said at least one connecting edge, said composite material comprising a fiber reinforcement consisting of randomly oriented short fibers.

7. The method according to claim 6, wherein: The fabrication of the structural body comprises three-dimensional or multi-layer weaving of fiber reinforcement and densification of the fiber reinforcement by a ceramic matrix.

8. The method according to claim 7, wherein: Fixing of each connecting edge to the structural body is carried out by brazing, by mechanical connection or by co-siliconization.

9. The method according to claim 6, wherein: The structural body is made of metal material.

10. The method according to claim 6, wherein: The fixing of each connecting edge to the structural body is carried out by brazing or by mechanical connection.

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