High-modulus fiber hard rod woven preform and preparation method thereof

Abstract

The invention discloses a high-modulus fiber hard rod woven preform and a preparation method thereof. The preparation method comprises the following steps: (1) preparing a high-modulus fiber rod by adopting a pultrusion process; (2) designing and processing a weaving mold; (3) inserting and fixing the high-modulus fiber rods on the processing and weaving mold along the Z-axis direction to form a fiber rod array according to the size requirement of the prefabricated body; (4) a layer of X-axis fiber rods and a layer of Y-axis fiber rods are laid in the fiber rod array channel in the X-axis direction and the Y-axis direction respectively; forming a unit layer; (5) inserting + 45-degree and / or-45-degree fiber rods after the number of unit layers reaches 4-6; and (6) repeating the steps (4)-(5) until the designed height of the prefabricated body is reached to obtain the prefabricated body. According to the method, the boundary dimension and spacing of the fabric can be designed to the maximum extent, and the requirement for shape integrity of the prefabricated body is met; the obtained fabric is good in regularity, strong in designability, high in prefabricated body density, and high in overall stability and mechanical property.

Description

Technical Field

[0001] The invention relates to the technical field of three-dimensional braided composite materials, and in particular to a high modulus fiber hard rod braided preform and a preparation method thereof. Background Art

[0002] High modulus fibers have high modulus but low strength. The fibers are prone to brittle fracture and poor wear resistance during the weaving process. The weaving damage is large, which seriously affects the fiber weaving performance and limits the application of high modulus fibers in braided composite materials.

[0003] U.S. Patent No. 4218276 prepares a preform by laying carbon fiber cloth on a Z-direction steel needle, puncturing and compacting it, and then replacing the steel needle with carbon fiber. At present, the preparation method of puncture preforms in China usually involves weaving carbon fiber into carbon cloth, pre-needling the carbon cloth and carbon fiber mesh composite material, puncturing the composite material on the steel needle to a certain height, and then replacing the steel needle with carbon fiber to prepare the carbon fiber preform. Although the carbon cloth type, needle punching parameters, etc. have been continuously optimized in subsequent studies, the carbon fiber bundles still have bending and wear during the weaving process.

[0004] Chinese patent CN106400271A discloses a three-way bias fabric, its weaving device and its weaving method. The bias fabric is based on a fine-weaving puncture process, including an XY plane fiber unit layer and a Z-direction fiber bundle or fiber rod. Through process improvement, a specific angle can be formed between the XY plane and the Z direction. This patent breaks through the limitation of the traditional puncture fabric XY plane and the Z-direction fiber or fiber rod forming a 90° angle, and can achieve an angle change in the range of 0° to 90°. However, in this patent, only the Z-direction fiber rod forms an angle with the same plane unit cloth layer, and the XY direction is composed of a plane fiber cloth unit layer, and the overall stability and mechanical properties of the resulting preform are poor.

[0005] Chinese patent CN110184722B discloses a method for preparing a carbon fiber preform by puncturing a carbon rod, which is to directly puncture the carbon rod by setting one end of the carbon rod in a needle-like shape, and then push the carbon rod upward and compact it after completing a cycle of yarn laying, and repeat this process to obtain a preform. This process uses carbon fiber bundles to be directly laid during XY-direction forming. Carbon fiber bundles with a width that matches the channel width can enhance the flatness and fit of the XY-direction fibers, which is beneficial to exerting the fiber's own strength. However, during the laying process, the fibers are not hardened and protected by resin, and damage will still occur; at the same time, although this patent uses carbon fiber rods to participate in weaving, it is limited to the Z direction, and the overall stability and mechanical properties of the preform are poor.

[0006] Chinese patent CN113481655B "A braiding device and braiding method for a throat lining preform" includes the following steps: a flat rod is wound on a flat rod reel, the flat rod is inserted through a flat rod insertion head, and a vertical rod is set on a rod bundle tray; a vertical rod conveying mechanism is set at the bottom of the vertical rod tray, and a rotating mechanism is set at the bottom of the vertical rod conveying mechanism; the vertical rods and flat rods form a braided body. The cross section of the fiber vertical rod mentioned in the patent is a square or regular triangle, and the density of the preform is difficult to increase, and the overall stability and mechanical properties of the preform are poor. Summary of the invention

[0007] In order to solve the technical problems that the existing high modulus fiber has poor weaving performance, the fiber is easy to break during continuous weaving, and the preform formed by weaving has poor stability and mechanical properties, the present invention provides a high modulus fiber hard rod weaving preform and its preparation method.

[0008] The technical solution adopted by the present invention is:

[0009] A method for preparing a high modulus fiber hard rod braided preform comprises the following steps:

[0010] (1) High modulus fiber rods with different cross-sectional shapes are prepared by pultrusion process;

[0011] (2) designing and processing a weaving mold, wherein a plurality of fiber rod mounting holes extending along the Z-axis direction are evenly opened on the weaving mold;

[0012] (3) according to the size requirements of the preform, the high modulus fiber rod obtained in step (1) is inserted and fixed into the fiber rod mounting hole along the Z-axis direction to form a fiber rod array;

[0013] (4) in the fiber rod array obtained in step (3), laying a layer of the high modulus fiber rod obtained in step (1) in the channel of the fiber rod array along the X-axis direction;

[0014] (5) above the X-axis high modulus fiber rod of step (4), a layer of high modulus fiber rod obtained in step (1) is laid in the channel of the fiber rod array along the Y-axis direction to form a unit layer having X-axis high modulus fiber rod and Y-axis high modulus fiber rod;

[0015] (6) Repeat steps (4)-(5), and when the unit layer reaches 4-6 layers, insert the high modulus fiber rod obtained in step (1) at +45° and / or -45° between the X-axis high modulus fiber rod and the Y-axis high modulus fiber rod along the axial direction at an angle of 45° to the X-axis or Y-axis to form a structural layer with high modulus fiber rods in the X-axis, Y-axis and 45° axes;

[0016] (7) Repeat step (6) until the designed height of the preform is reached;

[0017] (8) The preform obtained in step (7) is taken out from the weaving mold and compacted to obtain a high modulus fiber hard rod weaving molded preform.

[0018] Furthermore, in step (6), a pressurizing device is used to compact the high modulus fiber rods of the X-axis, Y-axis and 45° axis of the structural layer along the Z direction, thereby further improving the volume density and mechanical properties of the preform.

[0019] Furthermore, the preparation method of the high modulus fiber rod in step (1) is: winding a single strand or a combined high modulus fiber on a creel, and after pulling, dipping, pultruding, and curing, cutting it to a fixed length to obtain high modulus fiber rods with different cross-sectional shapes; the fiber volume fraction of the obtained high modulus fiber rod is 30% to 60%.

[0020] Furthermore, before the rod is made, the high modulus fiber is sized with a sizing agent, wherein the sizing agent is polyvinyl alcohol, phenolic resin or vinyl ester resin, so as to improve the fiber bundling and wear resistance.

[0021] Furthermore, the high modulus fiber contains 0-90% by mass of inorganic fiber, and the inorganic fiber is at least one of quartz fiber, ceramic fiber and metal fiber. Adding inorganic fiber such as quartz fiber, ceramic fiber or metal fiber for mixed weaving can enhance material performance or achieve special functions; this mixed weaving technology not only enriches the mechanical properties of the material, but also gives new properties to the composite material, greatly expanding its application range.

[0022] Furthermore, the high modulus fiber is at least one of polyacrylonitrile-based carbon fiber, mesophase pitch-based carbon fiber and silicon carbide fiber, so as to further improve the overall stability and mechanical properties of the preform.

[0023] Furthermore, the cross-sectional shape of the high modulus fiber rod obtained in step (1) is rectangular, circular or elliptical, and the cross-sectional shapes of the high modulus fiber rods in steps (3)-(5) are the same or different. Fiber rods with various cross-sectional shapes can be flexibly matched to prepare preforms, which is conducive to adjusting the size, pore distribution and density of the fabric, and can design the fabric size and spacing to the greatest extent, meet the requirements of the integrity of the three-dimensional fabric shape, and further improve the overall stability and mechanical properties of the preform.

[0024] Furthermore, the straightness of the high modulus fiber rod obtained in step (1) is ≤0.5 mm / 500 mm, which is beneficial to reduce the damage to the fabric during weaving and further improve the overall stability and mechanical properties of the preform.

[0025] A high modulus fiber hard rod braided preform is prepared by any one of the preparation methods described above.

[0026] Furthermore, the fiber volume content of the high modulus fiber hard rod braided preform is 35% to 50%.

[0027] Beneficial effects of the present invention:

[0028] 1. Through the pultrusion process, a variety of cross-sectional shapes of high modulus fiber rods can be prepared. With the weaving mold, it is possible to use XYZ-45° axial circular, elliptical or rectangular fiber rods, or XY sampling rectangular fiber rods, Z and 45° axial sampling circular or elliptical fiber rods; or XY sampling circular fiber rods or elliptical fiber rods, Z and 45° axial sampling rectangular fiber rods and other combinations to weave preforms, so that the fabric size and spacing can be designed to the greatest extent to meet the requirements of the integrity of the preform shape; and the alternating configuration between the hard rods can effectively enhance the overall stability and mechanical properties of the preform. At the same time, it also allows the preform to adjust the fiber volume content according to different application requirements to achieve the purpose of both lightweight and strength. In addition, by precisely controlling the size and arrangement of the template pores, the performance of the material can be further optimized, broadening its application prospects in high-end fields such as aerospace.

[0029] 2. By using preformed fiber rod substrate for weaving, the fibers in the three directions of X, Y, and Z are protected by the resin in the rigid rods during the fabric forming process, which can reduce the damage of the fibers during the weaving process and effectively solve the problem of high modulus fiber damage during the weaving process; at the same time, the diversified weaving methods and fiber combination methods enable the preform to maintain structural strength while meeting the special requirements for material properties in different environments.

[0030] 3. The use of a woven mold with hole spacing for Z-direction forming of the preform enables the hard rod method to construct the preform, ensuring the spacing accuracy and the reliability and stability of Z-direction forming. The structure of the orifice plate matches the filling rate of the fiber, which is conducive to the infiltration of carbon-based, resin-based, and ceramic matrices, and is conducive to optimizing the composite channel in the later stage; making the composite material show better physical and chemical properties under extreme environments such as high temperature and high pressure, providing strong support for material innovation in high-tech fields such as aerospace.

[0031] 4. The method of the present invention can not only improve the production efficiency and material properties of the preform, but also significantly reduce its production cost. The finished fabric has good regularity, less post-composite processing, high uniformity, strong designability, and the fabric has 45-degree directional fibers, which can increase the volume content of the fabric and improve the overall spatial torsion resistance of the fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a process flow chart for preparing variable-section high-modulus fiber rods.

[0033] Figure 2 for Figure 1 Schematic diagram of the structure of a medium circular pultrusion die.

[0034] Figure 3 for Figure 1 Schematic diagram of the structure of the medium rectangular pultrusion die.

[0035] Figure 4 for Figure 1 Schematic diagram of the structure of the medium elliptical pultrusion die.

[0036] Figure 5 It is a schematic diagram of the structure of the weaving mold with a rectangular inner hole of the present invention.

[0037] Figure 6 It is a schematic diagram of the structure of the weaving mold with a circular inner hole of the present invention.

[0038] Figure 7 This is a schematic diagram of the structure of the high modulus fiber rod braided preform prepared in Example 1. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and a preferred implementation manner.

[0040] See also Figure 1-Figure 4 The present invention discloses a method for preparing a high modulus fiber hard rod, the steps of which are as follows:

[0041] (1) Winding a single strand or a plied strand of high modulus fiber 2 impregnated with a sizing agent on a creel 1;

[0042] (2) Under the action of the traction mechanism 6, the high modulus fiber 2 on the creel 1 is impregnated with resin in the impregnation tank 3 and then enters the pultrusion die 4. The pultrusion die is provided with a circular, rectangular or elliptical inner hole. The fiber impregnated with resin forms a wet rod with a circular, rectangular or elliptical cross section under the constraint of the shape of the inner hole. The wet rod coming out of the pultrusion die 4 enters the drying oven 5. After drying, the resin is solidified to obtain a dry rod with a certain elasticity and a circular, rectangular or elliptical cross section shape, which is wound on the winding mechanism 7;

[0043] (3) When in use, the dry rod on the winding mechanism 7 is cut into a fixed length according to the process requirements to obtain a high modulus fiber hard rod for weaving.

[0044] The sizing agent in step (1) is preferably polyvinyl alcohol, phenolic resin or vinyl ester resin, and the sizing process is sampled from the prior art. The high modulus fiber 2 is preferably at least one of polyacrylonitrile-based carbon fiber, mesophase pitch-based carbon fiber and silicon carbide fiber, which may contain 0 to 90% by mass of inorganic fiber, wherein the inorganic fiber is at least one of quartz fiber, ceramic fiber and metal fiber.

[0045] In step (2), the extrusion amount of the resin is controlled by a pultrusion die so that the fiber volume fraction of the obtained high modulus fiber rigid rod is 30% to 60%.

[0046] See also Figure 5-6 The present invention also discloses a weaving mold, which is a rectangular body with rectangular, circular or elliptical countersunk holes (not shown in the figure) evenly opened on the upper side, the hole spacing and hole diameter are adapted to the cross-sectional size of the high modulus fiber hard rod, and the number of holes is adapted to the overall size and performance of the preform. The countersunk holes should be set to a certain depth so that the high modulus fiber hard rod inserted into the hole can remain in a vertical state. Figure 5 As shown, a number of square high modulus fiber hard rods are inserted into the braiding die at equal intervals; Figure 6 As shown, several round high modulus fiber hard rods are inserted into the braiding mold at equal intervals.

[0047] The following describes in detail the method for preparing the high modulus fiber hard rod braided preform of the present invention with several specific examples.

[0048] Embodiment 1:

[0049] See also Figure 1 , Figure 1 is a structural layer of the prefab. Figure 1 The blue arrow points to the Z axis, the red arrow points to the Y axis, and the green arrow points to the X axis.

[0050] In this embodiment, the size of the preform is required to be 400mm×400mm×400mm, and the braided fiber is sampled from silicon carbide fiber. The preparation method is as follows:

[0051] (1) using 10% by weight polyvinyl alcohol glue as a sizing agent, placing silicon carbide fiber in the sizing agent for treatment, and the content of the silicon carbide fiber sizing agent is 12% by weight of the silicon carbide fiber;

[0052] (2) The high modulus fiber hard rod is prepared by the method described above, that is, 8 strands of sized silicon carbide fibers are pulled, dipped, extruded, and cured to form a circular silicon carbide fiber rod with a cross section of Φ2.0 mm, which is cut to a length of 450 mm for standby use; the dipping agent is a high temperature resistant phenolic resin;

[0053] (3) Use Figure 6 The braiding mold shown, insert the circular silicon carbide fiber rod obtained in step (2) into the inner hole along the Z direction to form a square matrix array, and the array channel width is 2.2mm;

[0054] (4) Along the X-axis direction, a round silicon carbide fiber rod is laid in each array channel; above the X-axis silicon carbide fiber rod, along the Y-axis direction, a round silicon carbide fiber rod is laid in each array channel; forming a unit layer having X-axis high modulus fiber rods and Y-axis high modulus fiber rods;

[0055] (5) When the number of unit layers reaches 4, silicon carbide fiber rods with an axial direction of 45° are inserted between the second unit layer and the third unit layer, and between the third unit layer and the fourth unit layer along the axial direction at an angle of +45° to the Y axis, the 45° axis fiber rods between the second unit layer and the third unit layer pass through the first and second unit layers, and the 45° axis fiber rods between the third unit layer and the fourth unit layer pass through the first, second and third unit layers; forming a structural layer with high modulus fiber rods in the X axis, Y axis and 45° axis;

[0056] (6) Using a pressurizing device, four layers of rectangular silicon carbide fiber rods are compacted to an average interlayer spacing of 0.45 mm, and after pressurization, a special fixing ring is used to fix them along the Z direction;

[0057] (7) Repeat steps (4) to (6) until the designed height of the preform reaches 400 mm, thereby obtaining a silicon carbide fiber rod molding preform.

[0058] The volume density of the obtained silicon carbide fiber rod preform is 1.30g / cm 3 , fiber volume fraction 52%. The preform is woven with rectangular rods in three directions. Compared with the existing steel needle puncture preform, the density is significantly improved. The ceramic matrix composite material reinforced by silicon carbide fiber braid has excellent anti-oxidation and ablation resistance.

[0059] Embodiment 2:

[0060] In this embodiment, the size of the preform is required to be 200 mm×200 mm×300 mm, and the braided fibers are 2K mesophase pitch-based carbon fibers and metal fibers. The preparation method is as follows:

[0061] (1) using 8% by mass polyvinyl alcohol glue as a sizing agent, placing 2K mesophase asphalt-based carbon fiber in the sizing agent for treatment, and the content of the mesophase asphalt-based carbon fiber sizing agent is 5% by mass of the carbon fiber;

[0062] (2) The high modulus fiber hard rods were prepared by the method described above, that is, 2-axis 2K mesophase asphalt-based carbon fibers and 4 strands of metal fibers were pulled, impregnated, pulled and cured to form rectangular carbon fiber rods with a cross-section of 1.0 mm × 1.0 mm and round carbon fiber rods with a diameter of 1.0 mm. The rectangular carbon fiber rods were used for fabric X- and Y-direction molding, and the round carbon fiber rods were used for fabric Z-direction molding. Both specifications were cut to length, and the cutting length was 350 mm. Vinyl ester resin was used as the impregnating agent.

[0063] (3) Use Figure 5 The braiding mold shown is used to insert a circular carbon fiber rod into the inner hole along the Z direction to form a square matrix array, and the array channel width is 1.2 mm; a yarn fixing tool is set circumferentially at one end of the carbon fiber rod;

[0064] (4) Along the X-axis direction, a rectangular carbon fiber rod is laid in each array channel; a total of 201 carbon fiber rods need to be laid;

[0065] (5) Above the X-axis carbon fiber rod, along the Y-axis direction, a rectangular carbon fiber rod is laid in each array channel, and a total of 201 carbon fiber rods need to be laid;

[0066] (6) After laying 6 unit layers, insert silicon carbide fiber rods with an axis direction of 45° between each unit layer along the axial direction at an angle of +45° and -45° to the Y axis, and make the silicon carbide fiber rods with an axis direction of 45° of each layer pass through the first unit layer from top to bottom, so as to form a structural layer with high modulus fiber rods in the X axis, Y axis and 45° axis;

[0067] (7) A pressurizing device is used to compact the six layers of rectangular silicon carbide fiber rods until the average interlayer spacing is 0.6 mm, and after pressurization, a special fixing ring is used to fix them along the Z direction;

[0068] (8) Repeat steps (4) to (7) until the designed height of the preform reaches 300 mm, thereby obtaining a mesophase asphalt-based carbon fiber hard rod molded preform;

[0069] The bulk density of the mesophase pitch-based carbon fiber hard rod preform is 0.95 g / cm 3 , fiber volume fraction 45%. The X-direction and Y-direction designs use rectangular carbon fiber rods to weave preforms, and the Z-direction design uses round carbon fiber rods to form. Compared with the existing steel needle puncture preforms, the density is significantly improved. Due to the small damage to the molded fibers, the mechanical properties of the material are significantly improved.

[0070] Embodiment 3:

[0071] In this embodiment, the size of the preform is required to be Φ200mm×200mm, and the braided fibers are Toray M55J carbon fibers and metal wires. The preparation method is as follows:

[0072] (1) Using 10% by mass polyvinyl alcohol glue as a sizing agent, Toray M55J carbon fiber is placed in the sizing agent for treatment, and the carbon fiber sizing agent content is 8% by mass of the carbon fiber;

[0073] (2) The high modulus fiber hard rod was prepared by the method described above, that is, 6 strands of sized M55J carbon fiber and 6 metal wires were pulled, dipped, extruded, and cured to form a rectangular carbon fiber rod with a cross-section of 1.8 mm × 1.8 mm and a round carbon fiber rod with a diameter of Φ1.8 mm, and the cutting length was 250 mm; the dipping agent used a high temperature resistant phenolic resin, and a silane coupling agent was added to enhance the bonding performance between the metal fiber and the resin;

[0074] (3) Use Figure 6 The braiding mold shown is used to insert a circular carbon fiber rod into the inner hole along the Z direction to form a square matrix array. The array channel width is 2.0 mm, and a yarn fixing tool is set circumferentially at one end of the carbon fiber rod;

[0075] (4) Along the X-axis direction, a rectangular carbon fiber rod is laid in each array channel; a total of 180 carbon fiber rods need to be laid;

[0076] (5) Above the X-axis carbon fiber rod, along the Y-axis direction, a rectangular carbon fiber rod is laid in each array channel; a total of 180 carbon fiber rods need to be laid;

[0077] (6) After laying 5 unit layers, silicon carbide fiber rods with an axis direction of 45° are inserted between each unit layer along the axial direction at an angle of +45° and -45° to the Y axis, and the silicon carbide fiber rods with an axis direction of 45° of each layer are passed through the first unit layer from top to bottom, so as to form a structural layer with high modulus fiber rods in the X-axis, Y-axis and 45° axis;

[0078] (7) A pressurizing device is used to compact the six layers of rectangular silicon carbide fiber rods until the average interlayer spacing is 0.5 mm, and after pressurization, a special fixing ring is used to fix them along the Z direction;

[0079] (8) Repeat steps (4) to (7) until the preform height reaches 200 mm, thereby obtaining a preform formed of an M55J carbon fiber rod;

[0080] The volume density of the M55J carbon fiber rod preform is 0.85 g / cm 3 , fiber volume fraction 48%. Compared with the existing steel needle puncture preform, the preform X, Y, Z directions are all woven with round rods, and composite channels are reserved, which is more conducive to the deposition of the matrix and significantly shortens the composite cycle; in addition, the profiling design is easy to process, and the introduction of metal wire makes the ablation resistance of the preform enhanced ablation material more excellent.

[0081] The above descriptions are merely embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a high modulus fiber hard rod braided preform, characterized in that: The following steps are involved: (1) High modulus fiber rods with different cross-sectional shapes are prepared by pultrusion process; (2) designing and processing a weaving mold, wherein a plurality of fiber rod mounting holes extending along the Z-axis direction are evenly opened on the weaving mold; (3) according to the size requirements of the preform, the high modulus fiber rod obtained in step (1) is inserted and fixed into the fiber rod mounting hole along the Z-axis direction to form a fiber rod array; (4) in the fiber rod array obtained in step (3), laying a layer of the high modulus fiber rod obtained in step (1) in the channel of the fiber rod array along the X-axis direction; (5) above the X-axis high modulus fiber rod of step (4), a layer of high modulus fiber rod obtained in step (1) is laid in the channel of the fiber rod array along the Y-axis direction to form a unit layer having X-axis high modulus fiber rod and Y-axis high modulus fiber rod; (6) Repeat steps (4)-(5), and when the unit layer reaches 4-6 layers, insert the high modulus fiber rod obtained in step (1) at +45° and / or -45° between the X-axis high modulus fiber rod and the Y-axis high modulus fiber rod along the axial direction at an angle of 45° to the X-axis or Y-axis to form a structural layer with high modulus fiber rods in the X-axis, Y-axis and 45° axes; (7) Repeat step (6) until the designed height of the preform is reached; (8) The preform obtained in step (7) is taken out from the weaving mold to obtain a high modulus fiber hard rod weaving molded preform.

2. The preparation method according to claim 1, characterized in that: In step (6), a pressurizing device is used to compact the high modulus fiber rods of the structural layer along the X-axis, Y-axis and 45° axis along the Z-direction.

3. The preparation method according to claim 1, characterized in that: The preparation method of the high modulus fiber rod in step (1) is as follows: a single strand or a combined high modulus fiber is wound on a yarn frame, and after pulling, dipping, pulling, and curing, the fiber is cut to a fixed length to obtain high modulus fiber rods of different cross-sectional shapes; the fiber volume fraction of the obtained high modulus fiber rod is 30% to 60%.

4. The preparation method according to claim 3, characterized in that: Before the rod is made, the high modulus fiber is sizing treated with a sizing agent, wherein the sizing agent is polyvinyl alcohol, phenolic resin or vinyl ester resin.

5. The preparation method according to claim 2, characterized in that: The high modulus fiber contains 0-90% by mass of inorganic fiber, and the inorganic fiber is at least one of quartz fiber, ceramic fiber and metal fiber.

6. The preparation method according to claim 5, characterized in that: The high modulus fiber is at least one of polyacrylonitrile-based carbon fiber, mesophase pitch-based carbon fiber and silicon carbide fiber.

7. The preparation method according to claim 1, characterized in that: The cross-sectional shape of the high modulus fiber rod obtained in step (1) is rectangular, circular or elliptical; the cross-sectional shapes of the high modulus fiber rods in steps (3)-(5) are the same or different.

8. The preparation method according to claim 1, characterized in that: The straightness of the high modulus fiber rod obtained in step (1) is ≤0.5mm / 500mm.

9. A high modulus fiber hard rod braided preform, characterized in that: The method is prepared by any one of claims 1 to 8.

10. The high modulus fiber hard rod braided preform according to claim 9, characterized in that: The fiber volume content is 35% to 50%.

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