Connecting structure of CMC material and metal material combined turbine blade

Abstract

The invention provides a connecting structure of a CMC material and metal material combined turbine blade, and belongs to the technical field of aerospace, the combined turbine blade comprises a metal blade body and edge plates, the metal blade body is provided with a CMC front edge, the edge plates comprise a metal edge plate and a CMC edge plate, and the CMC edge plate is located on the side, close to the metal blade body, of the edge plate; the connecting structure is arranged at the joint of the metal margin plate and the CMC margin plate and comprises a CMC area, an MMC area and a metal area, the CMC area is located on the CMC margin plate, the metal area is located on the metal margin plate, the CMC area is arranged to be of a composite structure of a first fiber woven prefabricated body and a ceramic matrix, the MMC area is arranged to be of a composite structure of a second fiber woven prefabricated body and metal, and the metal area is arranged to be of a composite structure of a second fiber woven prefabricated body and metal. And the material of the metal region is the same as that of the MMC region metal. According to the scheme, the use of a welding technology can be avoided, and high-performance connection of the ceramic matrix composite turbine blade and the metal margin plate is achieved.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and particularly to a connection structure for a combined turbine blade of CMC material and metal material. Background Art

[0002] The turbine inlet temperature of the next-generation high-performance aeroengine has increased sharply. The temperature resistance performance of existing metal materials can no longer meet the working requirements of turbine blades. At present, the safe operating temperature of ceramic matrix composites (CMC) has reached as high as 1350 °C, and it may even exceed 1500 °C in the future. This makes CMC materials an important candidate material for future advanced aeroengine turbine blades. (Takashi T, Kunkel B, Deverler M, et al. Research of CMC Application to Turbine Composite. IHI Engineering Review, 2005, 38:58-62.). Although CMC materials represented by 2.5-dimensional woven ceramic matrix composites (2.5D CMC) have a higher safe operating temperature than superalloys, on the one hand, all-CMC turbine blades inevitably need to be combined with metal components, and on the other hand, adjustable CMC turbine blades are not yet mature. Therefore, turbine blades combined with CMC materials and metal materials have broad application prospects in practical engineering applications.

[0003] Turbine blades combined with CMC materials and metal materials face an important problem, that is, the connection between CMC materials and metal materials. Existing connections for CMC materials and metal materials mostly use dissimilar material welding technology for welding. However, there are significant differences in heat transfer and mechanical properties between CMC materials and metal materials, which lead to the following three severe problems in the connection parts of existing turbine blades combined with CMC materials and metal materials (Shen Xiaoqin, Li Yajiang, Wang Juan, et al. Research Status of Ceramic Matrix Composite / Metal Welding. Welding Technology, 2007, 36(4):8-11.): First, thermal stress during heating in the welding area causes cracks to appear in the connection area; second, some ceramics will melt and evaporate during welding, resulting in impossible welding; finally, most ceramics have poor electrical conductivity, making it difficult to apply welding methods such as resistance welding. Summary of the Invention

[0004] In view of this, an embodiment of the present application provides a connection structure for a combined turbine blade of CMC material and metal material. This new connection structure is based on the woven structure inside the fiber-reinforced ceramic matrix composite material, overcomes the connection problem when forming a combined turbine blade with an existing CMC material turbine blade and a metal flange, and at the same time, in combination with the integrated high-performance connection requirements of the combined turbine blade, a new integrated transition connection structure is proposed. This new integrated transition connection structure has the highly integrated characteristics of a trinity of ceramic matrix composite material, metal matrix composite (MMC), and metal material, and can achieve high-performance connection between the CMC material turbine blade and the metal flange while avoiding welding.

[0005] An embodiment of the present application provides a connection structure for a combined turbine blade of CMC material and metal material. The combined turbine blade includes a metal blade body and flanges provided on both sides of the metal blade body. A CMC leading edge is provided on the metal blade body. The flange includes a connected metal flange and a CMC flange. The CMC flange is located on the side of the flange close to the metal blade body. It is characterized in that the connection structure is arranged at the connection between the metal flange and the CMC flange. The connection structure includes a CMC region, an MMC region, and a metal region connected in sequence. The CMC region is located on the CMC flange, the metal region is located on the metal flange, the CMC region is set as a composite structure of a first fiber woven preform and a ceramic matrix, the MMC region is set as a composite structure of a second fiber woven preform and a metal, and the material of the metal region is the same as the metal material of the MMC region.

[0006] According to a specific implementation manner of the embodiment of the present application, both the first fiber woven preform and the second fiber woven preform are set as 2.5D woven preforms.

[0007] According to a specific implementation manner of the embodiment of the present application, both the first fiber woven preform and the second fiber woven preform are provided with warp yarns and weft yarns. The weft yarns of the first fiber woven preform and the second fiber woven preform are both set as wavy, and the warp yarns of the first fiber woven preform and the second fiber woven preform are both set as straight.

[0008] According to a specific implementation manner of the embodiment of the present application, the length of the MMC region is set as an integer multiple of the pitch between two adjacent rows of warp yarns.

[0009] According to a specific implementation manner of the embodiment of the present application, the pitch between two adjacent rows of warp yarns of the first fiber woven preform is different from the pitch between two adjacent rows of warp yarns of the second fiber woven preform, and / or,

[0010] The number of warp layers of the first fiber woven preform is different from the number of warp layers of the second fiber woven preform.

[0011] According to a specific implementation manner of an embodiment of the present application, the first fiber woven preform is provided with warp yarns and weft yarns, the second fiber woven preform is provided with weft yarns, the warp yarns of the first fiber woven preform are arranged in a straight line, the weft yarns of the first fiber woven preform are wavy, and the weft yarns of the second fiber woven preform are arranged in a straight line formed by stretching the weft yarns of the first fiber woven preform.

[0012] According to a specific implementation manner of an embodiment of the present application, the width of the second fiber woven preform is the same as the width of the required connection part.

[0013] According to a specific implementation manner of an embodiment of the present application, the ceramic matrix is set as a SiC ceramic matrix.

[0014] Beneficial effects:

[0015] The connection structure of the CMC material and the metal material combined turbine blade in the embodiment of the present application forms an integrated transition connection structure that is a three-part transition combination of a CMC region, an MMC region, and a metal region. The connection part between the CMC region and the MMC region is effectively connected through the internal woven fibers, improving the connection strength. While avoiding the use of welding technology, the connection between the ceramic matrix composite structure and the metal material structure in the combined turbine blade can be realized.

[0016] The integrated transition connection structure of the present application makes full use of the fiber woven preform to realize the effective transition connection of the connection area, avoids the problem of physical property mismatch when directly welding the ceramic matrix composite structure and the metal material structure, and realizes the high-performance connection between the ceramic matrix composite turbine blade and the metal flange. Description of the drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the structure of a turbine blade combined with a CMC material and a metal material according to an embodiment of the present invention;

[0019] Figure 2 It is a welding schematic diagram of a turbine blade combined with a CMC material and a metal material in the prior art;

[0020] Figure 3 Schematic diagram of the connection structure of a CMC material and a metal material combined turbine blade according to an embodiment of the present invention;

[0021] Figure 4 Schematic diagram of the woven structure of the connection structure of a CMC material and a metal material combined turbine blade according to an embodiment of the present invention;

[0022] Figure 5 Another schematic diagram of the woven structure of the connection structure of a CMC material and a metal material combined turbine blade according to an embodiment of the present invention;

[0023] Figure 6 Schematic diagram of the position of the connection structure of a CMC material and a metal material combined turbine blade according to an embodiment of the present invention.

[0024] In the figure: 1, metal blade body; 2, metal upper flange; 3, metal lower flange; 4, CMC upper flange; 5, CMC leading edge; 6, CMC lower flange; 7, CMC area; 8, MMC structure; 9, metal area; 10, ceramic matrix; 11, metal; 12, warp yarn; 13, weft yarn; 14, first connection position; 15, second connection position; 16, third connection position; 17, fourth connection position. Detailed implementation manners

[0025] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0026] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts belong to the scope of protection of the present application.

[0027] It should be noted that the following describes various aspects of embodiments within the scope of the appended claims. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on this application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. Additionally, this apparatus and / or method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0028] It should also be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of this application. The diagrams only show the components related to this application and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in its actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0029] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the aspects described can be practiced without these specific details.

[0030] An embodiment of this application provides a connection structure for a combined turbine blade of CMC material and metal material. Taking a certain combined turbine blade as an example, as Figure 1 and Figure 3 shown, it is a schematic diagram of the combined turbine blade. The combined turbine blade includes a metal blade body 1, shroud plates provided on both sides of the metal blade body 1. A CMC leading edge 5 is provided on the metal blade body 1. The shroud plates include a connected metal shroud plate and a CMC shroud plate. The CMC shroud plate is located on the side of the shroud plate close to the metal blade body 1. The feature is that the connection structure is arranged at the connection of the metal shroud plate and the CMC shroud plate. The connection structure includes a CMC region 7, an MMC region 8, and a metal region 9 connected in sequence. The CMC region 7 is located on the CMC shroud plate, the metal region 9 is located on the metal shroud plate. The CMC region 7 is set as a composite structure of a first fiber woven preform and a ceramic matrix 10. The MMC region 8 is set as a composite structure of a second fiber woven preform and a metal 11. The material of the metal region 9 is the same as the material of the metal 11 in the MMC region 8.

[0031] As Figure 2As shown in the figure, it is a connection method of the connection part of the CMC material and the metal material in the combined blade in the prior art. The prior connection method is a dissimilar material welding method. After welding, a structural mutation between the two regions of 2.5D woven CMC and metal (high temperature alloy) will be formed in the connection area. However, the heat transfer and mechanical properties of CMC material and metal material are significantly different, which leads to a large thermal stress when the welding area is heated, and causes cracks in the connection area. Secondly, due to Figure 2 It can be seen that the junction area of ​​the two areas does not form an effective connection structure, which is easy to break when bent and sheared, and the connection performance is low.

[0032] Therefore, in view of the connection requirements of turbine blades composed of CMC materials and metal materials, and considering that when the current welding method for dissimilar materials is used for connection, problems such as large thermal stress and cracking are prone to occur in the connection area, this embodiment proposes a connection structure of turbine blades composed of CMC materials and metal materials, which has the highly integrated characteristics of ceramic-based composite materials, metal-based composite materials and metal materials. The connection part of the CMC area 7 and the MMC area 8 is effectively connected by the internal woven fibers, which improves the connection strength and overcomes the problem that the ceramic matrix 10 and the high-temperature alloy cannot be effectively connected. The integrated casting of the high-temperature alloy part in the MMC area 8 and the high-temperature alloy component (metal area 9) ensures the connection strength of each area and avoids welding, thereby finally realizing a high-performance integrated transition connection of turbine blades composed of ceramic-based composite materials and metal materials, and providing technical support for the dissimilar material connection of components such as turbine blades composed of CMC materials and metal materials.

[0033] Specifically, refer to Figure 1 The edge plate includes an upper edge plate and a lower edge plate. The leading edge of the combined turbine blade and a part of the upper and lower edge plates are made of 2.5D CMC material, such as Figure 1 The CMC upper edge plate 4, CMC leading edge 5 and CMC lower edge plate 6, the blade body and a part of the upper and lower edge plates are made of high temperature alloys, such as Figure 1 In order to meet the positioning and mechanical properties of the combined blade, the metal blade body 1, the metal upper edge plate 2 and the metal lower edge plate 3 need to be connected at the contact part between the CMC part of the combined blade and the high-temperature alloy. The specific connection position is referred to Figure 6 , including a first connection position 14, a second connection position 15, a third connection position 16 and a fourth connection position 17. During the connection process, the connection structure described in this embodiment can be applied to one or more different parts of the four connection positions according to the actual engineering needs of the combined blade to achieve high-performance connection of the combined blade.

[0034] In one embodiment, the first fiber woven preform and the second fiber woven preform are both configured as 2.5-dimensional woven preforms.

[0035] In one embodiment, referring to Figure 4 , both the first fiber woven preform and the second fiber woven preform are provided with warp yarns 12 and weft yarns 13. The weft yarns 13 of the first fiber woven preform and the second fiber woven preform are both arranged in a wavy shape, and the warp yarns 12 of the first fiber woven preform and the second fiber woven preform are both arranged in a straight line.

[0036] Specifically, the integrated connection structure is obtained by the transitional combination of three parts: the CMC region 7, the MMC region 8, and the metal region 9. During the manufacturing process of the integrated transitional connection structure, according to the woven structure required for the CMC turbine blade, a fiber woven preform with a certain woven structure is woven by fibers, such as Figure 4 the 2.5D woven preform composed of warp yarns 12 and weft yarns 13 in Figure 4 ; then a part of the 2.5D woven preform is compounded with the ceramic matrix 10 to form the CMC region 7 (such as mmc (the 2.5D woven CMC in mmc ). The part that is compounded with the ceramic matrix 10 is the first fiber woven preform, and the 2.5D woven preform (the second fiber woven preform) with a reserved length of L warp (the length of the MMC region 8) is not compounded with the ceramic matrix 10. Among them, the width of the second fiber woven preform is kept consistent with the width of the required connection part, and the length L Figure 4 is an integer multiple of the spacing L

[0037] between two adjacent rows of warp yarns 12; subsequently, the metal 11 is cast together with the reserved woven yarns to form the MMC region 8 (such as mmc the 2.5D MMC in warp ) and the metal region 9, and finally the connection structure of this embodiment is obtained.

[0038] In one embodiment, the length of the MMC region 8 is set to be an integer multiple of the spacing between two adjacent rows of warp yarns 12. For example, L mmc is set to 12 times the spacing L warp between two adjacent rows of warp yarns 12.

[0040] In one embodiment, the spacing between two adjacent rows of warp yarns 12 of the first fiber woven preform is different from that of the second fiber woven preform, and / or

[0039] the number of layers of the warp yarns 12 of the first fiber woven preform is different from that of the second fiber woven preform.

[0040] Specifically, during implementation, the internal weaving methods of the CMC region 7 and the MMC region 8 in the connection structure are the same, both being 2.5D weaving. The weaving parameters of the fibers inside these two regions can vary, such as the spacing and the number of layers between two adjacent rows of warp yarns 12 can be different.

[0041] In one embodiment, referring to Figure 5 , the first fiber woven preform is provided with warp yarns 12 and weft yarns 13, the second fiber woven preform is provided with weft yarns 13, the warp yarns 12 of the first fiber woven preform are arranged in a straight line, the weft yarns 13 of the first fiber woven preform are wavy, and the weft yarns 13 of the second fiber woven preform are arranged in a straight line formed by stretching the weft yarns 13 of the first fiber woven preform.

[0042] In this embodiment, a 2.5D woven - unidirectional toughening combined transition connection is formed. The internal weaving methods of the CMC region 7 and the MMC region 8 are different. In the internal fiber woven structure of the MMC region 8, the woven warp yarns 12 are removed, and the woven weft yarns 13 of the CMC region 7 are directly stretched over. Finally, in the integrated transition connection structure, the internal fibers of the CMC region 7 are in a 2.5D woven structure, and the inside of the MMC region 8 is unidirectional fiber toughening.

[0043] In one embodiment, the width of the second fiber woven preform is the same as the width of the required connection part.

[0044] In one embodiment, the ceramic matrix 10 is set as a SiC ceramic matrix.

[0045] The preparation method of the connection structure of the CMC material and the metal material combined turbine blade will be described in detail below, which specifically includes the following steps:

[0046] According to the woven structure required for the combined turbine blade, fiber is woven to form a fiber woven preform with a preset woven structure;

[0047] A part of the fiber woven preform is compounded with the ceramic matrix 10 to form the CMC region 7. The fiber woven preform compounded with the ceramic matrix 10 is set as the first fiber woven preform, and the reserved fiber woven preform is set as the second fiber woven preform;

[0048] The second fiber woven preform is cast with the metal 11 to form the MMC region 8 and the metal region 9, and the connection structure is obtained.

[0049] During specific implementation, for the compounding process of the fiber woven preform and the ceramic matrix 10, the SiC ceramic matrix is formed by the conversion of polycarbosilane in a high - temperature furnace. During the conversion and compounding process, the temperature in the high - temperature furnace is 1273 - 1323K.

[0050] In specific implementation, for the casting process of the fiber woven preform and the metal 11, a nickel-based high-temperature alloy is selected during the casting process, and the alloy raw materials are melted between 1500°C and 1600°C through a smelting equipment, and then the alloy solution is maintained at 1450°C to 1550°C and poured into a mold, and then directionally solidified at a cooling rate of 50°C / min to finally obtain MMC.

[0051] During the casting process of the metal 11, only the area with the reserved fiber woven structure can be cast, or an additional section of the pure metal area 9 can be cast outside the area. Finally, an integrated transition connection structure of the CMC area 7, the MMC area 8 and the metal area 9 is formed at the connection part.

[0052] In one embodiment, the fiber weaving method of the second fiber woven preform is:

[0053] Keeping the weaving parameters of the second fiber woven preform consistent with the weaving parameters of the first fiber woven preform to weave fibers, so as to form the second fiber woven preform; or

[0054] The warp yarns 12 in the first fiber woven preform are removed, and the weft yarns 13 in the first fiber woven preform are directly stretched to perform fiber weaving to form the second fiber woven preform.

[0055] Compared with the existing dissimilar material welding structure, the connection structure of the turbine blade composed of CMC material and metal material in this application has the following advantages:

[0056] like Figure 2 As shown in the figure, the existing connection method is a dissimilar material welding method. After welding, a structural mutation will be formed between the 2.5D woven CMC and the high-temperature alloy in the connection area. However, the heat transfer and mechanical properties of CMC materials and metal materials are significantly different. This will cause a large thermal stress to be generated when the welding area is heated, and cause cracks in the connection area. Secondly, as can be seen from the figure, the intersection of the two areas does not form an effective connection structure and is easy to break when bent and sheared. Figure 4 and Figure 5 As shown, in the connection structure proposed in the present application, the connection parts of the CMC region 7 and the MMC region 8 are effectively connected by the internal woven fibers, thereby improving the connection strength and overcoming the difficulty that the SiC matrix and the high-temperature alloy cannot be effectively connected. The integrated casting of the high-temperature alloy part in the MMC region 8 and the high-temperature alloy component ensures the connection strength of the two regions, and finally realizes the high-performance integrated transition connection of the turbine blade composed of ceramic-based composite materials and metal materials.

[0057] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A connection structure of a turbine blade composed of a CMC material and a metal material, the combined turbine blade comprising a metal blade body (1), and edge plates arranged on both sides of the metal blade body (1), the metal blade body (1) being provided with a CMC leading edge, the edge plates comprising a metal edge plate and a CMC edge plate connected to each other, the CMC edge plate being located on a side of the edge plate close to the metal blade body (1), characterized in that: The connection structure is arranged at the connection between the metal edge plate and the CMC edge plate, and the connection structure comprises a CMC region (7), an MMC region (8) and a metal region (9) which are connected in sequence, the CMC region (7) being located on the CMC edge plate, the metal region (9) being located on the metal edge plate, the CMC region (7) being arranged as a composite structure of a first fiber woven preform and a ceramic matrix (10), the MMC region (8) being arranged as a composite structure of a second fiber woven preform and a metal (11), and the material of the metal region (9) being the same as the material of the metal (11) of the MMC region (8).

2. The connection structure of the turbine blade composed of CMC material and metal material according to claim 1, characterized in that: The first fiber woven preform and the second fiber woven preform are both configured as 2.5-dimensional woven preforms.

3. The connection structure of the turbine blade composed of CMC material and metal material according to claim 2, characterized in that: The first fiber woven preform and the second fiber woven preform are both provided with warp yarns (12) and weft yarns (13); the weft yarns (13) of the first fiber woven preform and the second fiber woven preform are both arranged in a wavy shape; and the warp yarns (12) of the first fiber woven preform and the second fiber woven preform are both arranged in a straight shape.

4. The connection structure of the turbine blades composed of CMC material and metal material according to claim 3 is characterized in that: The length of the MMC area (8) is set to be an integer multiple of the spacing between two adjacent rows of warp yarns (12).

5. The connection structure of the turbine blade composed of CMC material and metal material according to claim 3, characterized in that: The spacing between two adjacent rows of warp yarns (12) of the first fiber woven preform is different from the spacing between two adjacent rows of warp yarns (12) of the second fiber woven preform, and / or, The number of layers of the warp yarns (12) of the first fiber woven preform is different from the number of layers of the warp yarns (12) of the second fiber woven preform.

6. The connection structure of the turbine blade composed of CMC material and metal material according to claim 1, characterized in that: The first fiber woven preform is provided with warp yarns (12) and weft yarns (13), and the second fiber woven preform is provided with weft yarns (13). The warp yarns (12) of the first fiber woven preform are arranged in a straight line shape, the weft yarns (13) of the first fiber woven preform are wavy, and the weft yarns (13) of the second fiber woven preform are arranged in a straight line shape formed by stretching the weft yarns (13) of the first fiber woven preform.

7. The connection structure of the turbine blade composed of CMC material and metal material according to claim 1, characterized in that: The width of the second fiber woven preform is the same as the width of the desired connection portion.

8. The connection structure of the turbine blades composed of CMC material and metal material according to claim 1, characterized in that: The ceramic matrix (10) is configured as a SiC ceramic matrix.

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