A ceramic matrix composite turbine vane integrated force transmission fiber structure and a preparation method thereof

Abstract

This invention relates to the field of turbine blade technology and discloses an integrated force-transmitting fiber structure for a ceramic matrix composite turbine guide vane and its preparation method. The integrated force-transmitting fiber structure for the turbine guide vane is composed of a continuous series skeleton fiber structure, a helical cured flange fiber structure, and an interlocking fiber structure. In the continuous series skeleton fiber structure, radial fibers extend from the top of the blade along the rim plate to the blade flange, ensuring a complete and continuous fiber path for the turbine guide vane's force transmission. In the blade flange, the helical cured flange fiber structure is helically wound around the radial skeleton fibers extending to the blade flange, forming a continuous fiber force-transmitting structure that adapts to the blade's structural characteristics, thereby achieving load transfer for the turbine guide vane. In this invention, the fibers within each structural feature are arranged along with the macroscopic blade body, rim plate, and blade flange, resulting in high consistency, low dispersion of mechanical properties, and avoiding the inevitable problems of cut edges or filler fibers after the blade body transitions to the rim plate in traditional plywood and braided structures.

Description

Technical Field

[0001] This invention relates to the field of turbine blade technology, and discloses an integrated force-transmitting fiber structure for a ceramic matrix composite turbine guide vane and its preparation method. Background Technology

[0002] The improvement of thrust-to-weight ratio and structural efficiency in advanced aero-engines increasingly relies on the application of advanced materials, processes, and related structures. Under the limitations of current domestic technology and materials, the use of high-temperature alloys in advanced engine turbine blades has already impacted engine performance and functionality. Therefore, there is an urgent need to conduct research on the application of high-strength, high-temperature resistant ceramic matrix composite (CMC) turbine blades.

[0003] The basic microstructure of CMCs is a composite structural material mainly composed of a matrix (SiC), an interface layer (BN), and fibers (SiC). CMC components achieve slippage between the fibers and the matrix, allowing the material to absorb more energy than elemental materials after plastic deformation, thus improving its macroscopic toughness. Therefore, the core of CMC component design lies in the structural design of its internal fibers.

[0004] Currently, the main fiber structures for CMCs turbine guide vanes both domestically and internationally are unidirectional belt, 2D layup, and braided structures. Unidirectional belt fiber structures typically involve curing fiber bundles with prepreg to form a fiber cloth with parallel unidirectional fibers, then interlacing and laying the unidirectional fiber cloth, and finally preparing a fiber-toughened polymer using prepreg. This structure results in less fiber bending and minimal loss of fiber performance, but the lack of constraint between parallel fiber bundles makes the component prone to crack propagation. 2D layup typically involves sewing fiber bundles into a fiber cloth with bidirectional perpendicular fibers, then interlacing or laying the 2D fiber cloth in parallel, and pressing it with a mold. A piercing and stitching process can also be used to tighten it into a three-dimensional prefabricated body. This structure has fiber reinforcement in two directions, but there is no fiber reinforcement between the layers, resulting in lower interlayer mechanical properties. Furthermore, the fabric has cut edges at the edges, leading to poor internal fiber consistency. The woven structure typically uses warp and weft threads interlaced in two or more layers, with the weft threads arranged in the gaps between the warp threads to form a three-dimensional fabric that is not layered. The structural components are a whole connected by fibers, but the fibers are bent a lot, resulting in a large loss of mechanical properties, making it difficult to adapt to the complex structure of turbine guide vanes. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated force-transmitting fiber structure for ceramic matrix composite turbine guide vanes and its preparation method, which can form a fiber-transmitting structure that is continuous and adaptable to the structural characteristics of the blade, and can avoid the problems of cut edges or filler fibers that are unavoidable after the blade transition plate of traditional plywood and braided structures.

[0006] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: An integrated force-transmitting fiber structure for a ceramic matrix composite turbine guide vane includes: A continuous series skeleton fiber structure includes radial skeleton fibers attached to the leaf body and circumferential fibers surrounding the leaf body, wherein the radial skeleton fibers and circumferential fibers are interwoven into a mesh structure. The radial skeleton fibers extend from the top of the blade along the edge plate to the blade flange; The blade flange is also provided with a spiral-cured flange fiber structure, which is spirally wound around the radial skeleton fiber extending to the blade flange. The edge plate is also provided with an interlocking fiber structure interwoven with the radial skeleton fibers.

[0007] Furthermore, the interlocking fiber structure is biased towards the blade shape of the blade body.

[0008] Furthermore, the interlocking fiber structure extends into the blade flange and serpentinely interweaves along the radial skeleton fiber direction in the blade flange to interlock the spiral-cured flange fibers, forming a continuous fiber force transmission structure.

[0009] To achieve the above-mentioned technical effects, the present invention also provides a method for preparing an integrated force-transmitting fiber structure for turbine guide vanes made of ceramic matrix composite materials, which is used to obtain the integrated force-transmitting fiber structure for turbine guide vanes, comprising: The two-dimensional fiber cloth formed by radial skeleton fibers and circumferential fibers is laid and shaped on the blade laying mold. The ends of the radial skeleton fibers are led out and extended along the flange to the blade flange; A spiral-cured flange fiber structure is formed by spirally winding a fiber structure around a radial skeleton fiber extending to the blade flange; An interlocking fiber structure is used to interweave radial skeleton fibers on the edge plate to form a two-dimensional fiber cloth laid on the edge plate.

[0010] Furthermore, one end of the spiral-cured flange fiber structure extends to the flange plate, and the two-dimensional fiber cloth formed by the interlocking fiber structure and the radial skeleton fiber interwoven on the flange plate is locally densified.

[0011] Furthermore, the location of the localized encryption is at the junction of the blade and the rim plate, or at the junction of the rim plate and the blade flange.

[0012] Furthermore, the spiral-cured flange fiber structure extending to the flange plate and the interlocking fibers are spaced apart on the flange plate.

[0013] Furthermore, the radial fibers extending to the blade flange are drawn from the radial fibers in the continuous tandem skeleton fiber structure and led along the flange to the blade flange.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention forms a turbine guide vane fiber force transmission structure with continuous fiber and adapted to the blade structure characteristics by adopting a continuous series skeleton fiber structure, a spiral cured flange fiber structure and an interlocking fiber structure, so as to realize the load transmission of the turbine guide vane; the fibers in the structural features are arranged with the macroscopic blade body, rim plate and blade flange, with high consistency and small mechanical property dispersion, and can avoid the problem of cut or filling fibers that inevitably occur after the blade body transitions to the rim plate in traditional plywood and braided structures. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the integrated force-transmitting fiber structure of the turbine guide vane in the embodiment; Figure 2 This is a schematic diagram of the radial skeleton fiber structure extending from the top of the blade along the edge plate to the blade flange in the embodiment; Figure 3 This is a schematic diagram of the spiral-cured flange fiber structure in the embodiment; Figure 4 This is a schematic diagram of the interlocking fiber structure in the embodiment; Among them, 1. blade; 2. radial skeleton fiber; 3. circumferential fiber; 4. flange; 5. blade flange; 6. spiral cured flange fiber structure; 7. interlocking fiber structure. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0017] Example 1 See Figures 1 to 4 An integrated force-transmitting fiber structure for a ceramic matrix composite turbine guide vane, comprising: The continuous series skeleton fiber structure includes radial skeleton fibers 2 attached to the blade 1 and circumferential fibers 3 surrounding the blade 1, wherein the radial skeleton fibers 2 and circumferential fibers 3 are interwoven into a mesh structure. The radial skeleton fiber 2 extends from the top of the blade 1 along the edge plate 4 to the blade flange 5; The blade flange 5 is also provided with a spiral-cured flange fiber structure 6, which is spirally wound around the radial skeleton fiber 2 extending to the blade flange 5. The edge plate 4 is also provided with an interlocking fiber structure 7 that is interwoven with the radial skeleton fiber 2.

[0018] In this embodiment, a continuous series skeleton fiber structure, a spiral-cured flange fiber structure 6, and an interlocking fiber structure 7 are used to form an integrated force-transmitting fiber structure for the ceramic matrix composite turbine guide vane. The radial fibers in the continuous series skeleton fiber structure extend from the top of the blade body 1 along the edge plate 4 to the blade flange 5, so that the force transmission path of the turbine guide vane has complete and continuous fibers. In the blade flange 5, the spiral-cured flange fiber structure 6 is spirally wound around the radial skeleton fibers 2 extending to the blade flange 5, forming a fiber-continuous force-transmitting structure that adapts to the structural characteristics of the blade, so as to realize the load transmission of the turbine guide vane. The fibers in each structural feature are arranged with the macroscopic blade body 1, edge plate 4, and blade flange 5, with high consistency and small dispersion of mechanical properties. It can also avoid the problem of cut edges or filling fibers that inevitably occur after the blade body 1 is transferred to the edge plate 4 in traditional plywood and braided structures.

[0019] Based on the same inventive concept, this embodiment also provides a method for preparing an integrated force-transmitting fiber structure for turbine guide vanes made of ceramic matrix composite materials, for obtaining the aforementioned integrated force-transmitting fiber structure for turbine guide vanes, comprising: The two-dimensional fiber cloth formed by radial skeleton fiber 2 and circumferential fiber 3 is laid and molded on the blade 1 laying mold. The ends of the radial skeleton fiber 2 are led out and extended along the flange 4 to the blade flange 5; A spiral-cured flange fiber structure 6 is formed by spirally winding a radial skeleton fiber 2 that extends to the blade flange 5 around the fiber structure. An interlocking fiber structure 7 is interwoven with radial skeleton fibers 2 on the edge plate 4 to form a two-dimensional fiber cloth laid on the edge plate 4.

[0020] In this embodiment, one end of the spiral-cured flange fiber structure 6 extends to the flange plate 4, and the two-dimensional fiber cloth formed by the interlocking fiber structure 7 and the radial skeleton fiber 2 intertwined on the flange plate 4 is locally densified, further optimizing the overall force transmission path of the turbine guide vane, ensuring that the load can be transmitted more evenly and stably, and effectively avoiding the occurrence of stress concentration.

[0021] In this embodiment, the localized reinforcement is located at the junction of the blade 1 and the edge plate 4, or at the junction of the edge plate 4 and the blade flange 5. By locally reinforcing the junction of the blade 1 and the edge plate 4, or at the junction of the edge plate 4 and the blade flange 5, the strength of these key parts can be significantly enhanced.

[0022] Example 2 See Figures 1 to 4An integrated force-transmitting fiber structure for a ceramic matrix composite turbine guide vane includes a continuous series skeleton fiber structure, a spiral-cured flange fiber structure 6, and a multifunctional interlocking fiber structure 7. The continuous series skeleton fiber structure is a 2D fiber cloth disposed on the turbine guide vane blade 1; the 2D fiber cloth is formed by interlacing radial skeleton fibers 2 attached to the blade blade 1 and circumferential fibers 3 surrounding the blade blade 1; some of the radial skeleton fibers 2 in the continuous series skeleton fiber structure are drawn out from the 2D fiber cloth of the blade blade 1 to form adaptive force-transmitting fibers, thereby connecting the blade blade 1, the shroud 4, and the blade flange 5 through the adaptive force-transmitting fibers, and adapting to any blade shape and the included angle between the shroud 4, thus having strong process adaptability. A spiral-cured flange fiber structure 6 is also provided on the blade flange 5. The spiral-cured flange fiber structure 6 is spirally wound around the radial skeleton fiber 2 extending to the blade flange 5. The rim plate 4 is provided with an interlocking fiber structure 7 offset from the blade body 1. The interlocking fiber structure 7 interweaves with the radial skeleton fiber 2 on the rim plate 4 to form a 2D fiber cloth on the rim plate 4. On the other hand, the interlocking fiber structure 7 extends into the blade flange 5 and bends through the spiral-cured flange fiber structure 6, interlocking with the gaps of the radial skeleton fiber 2. The number of interlocking turns and the bending length can be adjusted according to the macroscopic dimensions of the ceramic turbine guide vane flange. Finally, a continuous and integrated turbine guide vane force transmission path fiber structure is formed in the turbine guide vane blade body 1, rim plate 4, and blade flange 5. Compared with the commonly used turbine guide vane fiber structure, the internal structure of the force transmission fiber in this embodiment has continuous force transmission fibers, a high degree of integration, and strong interlayer strength.

[0023] In this embodiment, the continuous series skeleton fiber structure has continuous adjustable force transmission fibers in the edge plate 4 and blade flange 5. The fiber direction can be set to be parallel to the force transmission path of the turbine guide vane, and the spacing can be adjusted to further improve the designability of the mechanical properties of the force transmission path of the ceramic turbine guide vane.

[0024] In this embodiment, one end of the spiral-cured flange fiber structure 6 extends to the flange plate 4, and the two-dimensional fiber cloth formed by the interlocking fiber structure 7 and the radial skeleton fiber 2 interwoven on the flange plate 4 is locally densified, so as to achieve the function of tightening the force transmission fiber of the adjustable flange and further enhance the interlayer load-bearing capacity of the flange.

[0025] In some other embodiments, depending on the strength requirements of the force transmission path, the spiral-cured flange fiber structure 6 may also be drawn out by one or more flange plates 4 fibers offset from the leaf-shaped profile, further strengthening the fiber connection volume fraction of the flange plates 4 and the flange.

[0026] In some other embodiments, the multifunctional interlocking fiber structure 7 may employ the edge plate 4 fiber to enhance the interlocking capability of the fiber bundles in the continuous series skeleton fiber structure. Simultaneously, its fibers are offset to the blade profile, forming a variable angle with the continuous series skeleton fibers to accommodate the folding of the blade body 1 to the edge plate 4, avoiding the cuts or filler fibers of traditional plywood structures, thereby improving the consistency of the fiber structure.

[0027] Both the spiral-cured flange fiber structure 6 and the interlocking fiber structure 7 can be connected by multi-directional reinforced corner fibers. These fibers can be combined with the fibers at the flange corners at any angle in space, thereby improving the shear bearing capacity of the transition circle between the blade flange 5 and the flange plate 4.

[0028] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ceramic matrix composite turbine guide vane integrated force-transmitting fiber structure, characterized in that, include: A continuous series skeleton fiber structure includes radial skeleton fibers attached to the leaf body and circumferential fibers surrounding the leaf body, wherein the radial skeleton fibers and circumferential fibers are interwoven into a mesh structure. The radial skeleton fibers extend from the top of the blade along the edge plate to the blade flange; The blade flange is also provided with a spiral-cured flange fiber structure, which is spirally wound around the radial skeleton fiber extending to the blade flange. The edge plate is also provided with an interlocking fiber structure interwoven with the radial skeleton fibers.

2. The integrated power transmission fiber structure for turbine guide vanes according to claim 1, characterized in that, The interlocking fiber structure is biased towards the leaf shape of the blade.

3. The integrated power transmission fiber structure for turbine guide vanes and its preparation method according to claim 1, characterized in that, The interlocking fiber structure extends into the blade flange and serpentinely interweaves along the radial skeleton fiber direction in the blade flange to interlock the spiral-cured flange fibers, forming a continuous fiber force transmission structure.

4. A method for preparing an integrated force-transmitting fiber structure for turbine guide vanes made of ceramic matrix composite materials, used to obtain the integrated force-transmitting fiber structure for turbine guide vanes as described in any one of claims 1-3, characterized in that, include: The two-dimensional fiber cloth formed by radial skeleton fibers and circumferential fibers is laid and shaped on the blade laying mold. The ends of the radial skeleton fibers are led out and extended along the flange to the blade flange; A spiral-cured flange fiber structure is formed by spirally winding a fiber structure around a radial skeleton fiber extending to the blade flange; An interlocking fiber structure is used to interweave radial skeleton fibers on the edge plate to form a two-dimensional fiber cloth laid on the edge plate.

5. The method for preparing the integrated force-transmitting fiber structure for turbine guide vanes according to claim 4, characterized in that, One end of the spiral-cured flange fiber structure extends to the flange plate, and the two-dimensional fiber cloth formed by the interlocking fiber structure and the radial skeleton fiber interwoven on the flange plate is locally densified.

6. The method for preparing the integrated force-transmitting fiber structure for turbine guide vanes according to claim 5, characterized in that, The location of the localized encryption is at the junction of the blade and the rim plate, or at the junction of the rim plate and the blade flange.

7. The method for preparing the integrated force-transmitting fiber structure for turbine guide vanes according to claim 5, characterized in that, The spiral-cured flange fiber structure extending to the flange plate and the interlocking fibers are spaced apart on the flange plate.

8. The method for preparing the integrated force-transmitting fiber structure for turbine guide vanes according to claim 4, characterized in that, The radial fibers extending to the blade flange are drawn from the radial fibers in the continuous tandem skeleton fiber structure and led along the flange to the blade flange.

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