An apparatus for inducing orientation of magnetic filler in carbon fiber composites

Abstract

The utility model discloses a device of inducing magnetic filler to orient in carbon fiber composite material belongs to composite material preparation technical field. The device includes two equal size, equal surface magnetic intensity's permanent magnet, hole stainless steel support frame and stainless steel round bar. The support frame sets the circular hole, and the upper and lower side round bar restricts the permanent magnet to form the inhomogeneous magnetic field, and the middle round bar bears the composite material mould. The diameter of stainless steel round bar is less than the hole diameter, can adjust the permanent magnet spacing and change the magnetic field intensity, and the permanent magnet is high -temperature -resistant material, is suitable for high -temperature solidification environment. The device passes through the magnetic field and induces the filler such as magnetic boron nitride to orient in the composite material perpendicular to the carbon fiber direction, solves the problem of the mechanical property decline caused by traditional high filler amount, significantly improves the thermal conductivity under the low filler content, and retains the material mechanical strength. Simple structure is adjustable, and adapts to different size composite material preparation, and has practicality and industrial application potential.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber composite material preparation technology, specifically a device for inducing the orientation of magnetic boron nitride in carbon fiber composite materials. Background Technology

[0002] Carbon fiber composites are widely used in aerospace, new energy vehicles, and other fields due to their high strength, lightweight, and corrosion resistance. However, carbon fiber has a low radial thermal conductivity, and when combined with epoxy resin, its thermal conductivity perpendicular to the carbon fiber direction is generally below 1 W / (m·K), making it difficult to meet the high-efficiency and miniaturized heat dissipation requirements of spacecraft. Traditional methods of improving thermal conductivity by adding high thermal conductivity fillers such as graphene and boron nitride require high filler dosages, which can easily lead to a significant decrease in the mechanical properties of the composite material. Therefore, how to effectively improve thermal conductivity with low filler dosages has become a key technical challenge in this field.

[0003] In the existing technology, magnetic field-induced filler orientation is an efficient method, but there is a lack of dedicated devices that are suitable for the high-temperature curing process of carbon fiber composites and have adjustable magnetic field strength. Utility Model Content

[0004] To address the aforementioned problems, this invention provides a device for inducing the orientation of magnetic fillers in carbon fiber composite materials. By controlling the magnetic field, the magnetic fillers are oriented and arranged in a specific direction, thereby improving the thermal conductivity of the composite material with a low filler content while retaining its mechanical properties.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An apparatus for inducing the orientation of magnetic fillers in carbon fiber composites, comprising:

[0007] Permanent magnet assembly: Two permanent magnets of the same size and surface magnetic strength, symmetrically distributed vertically;

[0008] Perforated stainless steel support frame: located between the two permanent magnets, with symmetrically distributed circular holes at equal intervals, the circular holes being used to accommodate stainless steel rods;

[0009] Stainless steel round bars: including at least six bars, which are respectively inserted into the upper, middle and lower circular holes of the perforated stainless steel support frame;

[0010] Stainless steel rods with circular holes on the top and bottom are used to constrain permanent magnets, so that the two permanent magnets attract each other through magnetic force to form a non-uniform magnetic field.

[0011] A stainless steel rod inserted through a central circular hole is used to support the carbon fiber composite material mold.

[0012] As a further embodiment of this utility model: the diameter of the stainless steel round bar is smaller than the diameter of the circular hole in the perforated stainless steel support frame, so as to form an adjustable axial movement gap.

[0013] As a further embodiment of this utility model: the distance between the permanent magnets on the upper and lower sides of the perforated stainless steel support frame can be adjusted by adjusting the insertion position of the round bar, thereby changing the distance between the two permanent magnets and realizing the control of the magnetic field strength.

[0014] As a further aspect of this utility model: the permanent magnet is a high-temperature resistant permanent magnet that can stably provide a magnetic field in a high-temperature environment of 80℃-200℃.

[0015] As a further embodiment of this utility model, it also includes a carbon fiber composite material mold, which is detachably fixed on a stainless steel round bar in the middle position and is used to hold carbon fiber composite slurry containing magnetic boron nitride filler.

[0016] As a further embodiment of this invention: the magnetic filler is one or more combinations of boron nitride particles, graphene sheets, or iron-based / nickel-based magnetic ceramic particles with a magnetic coating on their surface.

[0017] As a further aspect of this invention: the direction of the non-uniform magnetic field is perpendicular to the surface of the carbon fiber composite material, so as to induce the magnetic boron nitride filler to form an orientation structure perpendicular to the carbon fiber direction in the composite material.

[0018] As a further aspect of this utility model, it includes the following steps:

[0019] Step S1: Based on the size data of the carbon fiber composite material to be prepared, select two permanent magnets with the same size and surface magnetic strength, select a perforated stainless steel support frame with a size larger than the permanent magnets, and select a stainless steel round bar with a diameter smaller than the diameter of the hole in the perforated stainless steel support frame.

[0020] Step S2: Insert the stainless steel round bar into the upper, middle and lower sides of the perforated stainless steel support frame, and place two permanent magnets of the same size and surface magnetic strength on the upper and lower sides of the perforated stainless steel support frame.

[0021] As a further improvement of this utility model, the following steps are included:

[0022] Step S1: Place the mold with carbon fiber composite material into the middle of the perforated stainless steel support frame;

[0023] Step S2: Place the two permanent magnets on the upper and lower sides of the perforated stainless steel support frame;

[0024] Step S3: Place the perforated stainless steel support frame into a high-temperature oven to complete the curing of the carbon fiber composite material;

[0025] Step S4: Demold the magnetic boron nitride oriented and cured carbon fiber composite material.

[0026] The advantages of this invention are as follows: This invention uses a high-temperature resistant permanent magnet, which can provide a magnetic field in a high-temperature environment; the magnetic field strength can be controlled by adjusting the height of the stainless steel round bars on the upper and lower sides of the perforated stainless steel support frame; this invention uses a permanent magnet device to induce the orientation of magnetic boron nitride in carbon fiber composite material, which greatly improves the thermal conductivity of the composite material and retains the excellent mechanical strength of carbon fiber composite material. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a device for inducing the orientation of magnetic boron nitride in carbon fiber composite material according to the present invention.

[0028] Figure 2 This is a front view of a device for inducing the orientation of magnetic boron nitride in carbon fiber composite materials according to the present invention.

[0029] Figure 3 This is a top view of a device for inducing the orientation of magnetic boron nitride in carbon fiber composite materials according to the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of a stainless steel round bar used in a device for inducing the orientation of magnetic boron nitride in carbon fiber composite materials according to this invention.

[0031] In the diagram: 1-Permanent magnet, 2-Perforated stainless steel support frame, 3-Stainless steel round bar, 4-Round hole. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] See Figures 1-4In this embodiment of the invention, a device for inducing the orientation of magnetic boron nitride in carbon fiber composite material includes two permanent magnets 1 of the same size and surface magnetic strength, a perforated stainless steel support frame 2, and a stainless steel rod 3. The perforated stainless steel support frame 2 is provided with a circular hole 4 for placing the stainless steel rod. Under the constraint of the stainless steel rod 3, the two permanent magnets 1 attract each other on the upper and lower sides of the perforated stainless steel support frame 2 to form a non-uniform magnetic field. In order to facilitate the insertion of the stainless steel rod 3 into the perforated stainless steel support frame 2, the diameter of the stainless steel rod 3 should be smaller than the diameter of the hole in the perforated stainless steel support frame 2. In order to provide different magnetic field strengths, the surface magnetic strengths of the two permanent magnets 1 can be selectively purchased, and the distance between the upper and lower circular holes 4 in the perforated stainless steel support frame 2 can be adjusted.

[0034] Example 1: Orientation of Magnetic Boron Nitride Filler and Performance Testing of Carbon Fiber Composites

[0035] 1. Device parameters

[0036] Permanent magnets: Two samarium cobalt permanent magnets with dimensions of 100mm×80mm×15mm (surface magnetic strength 3000mT, high temperature resistance 200℃);

[0037] Perforated stainless steel support frame: 120mm×100mm, with an initial spacing of 40mm between the upper and lower circular holes and a hole diameter of 5mm.

[0038] Stainless steel round bar: 4mm in diameter (forming a 1mm axial movement gap with the hole), the middle round bar supports a carbon fiber composite mold with dimensions of 80mm×80mm.

[0039] 2. Preparation of composite materials

[0040] Filler: Boron nitride particles with a ferromagnetic coating (particle size 1μm, filling amount 4wt%).

[0041] Matrix: Epoxy resin (E-51) and carbon fiber (T700, 50% by volume) composite slurry.

[0042] 3. Operating Procedures

[0043] Pour the slurry into the mold and place it on the central round bar;

[0044] Adjust the distance between the upper and lower permanent magnets to 80mm (achieved by replacing them with stainless steel round bars of 30mm in length) to form a non-uniform magnetic field perpendicular to the mold surface.

[0045] Place in a 150℃ oven to cure for 3 hours, and the magnetic field continuously induces the orientation of the filler.

[0046] Performance was tested after demolding.

[0047] 4. Test Results

[0048] Vertical thermal conductivity: 1.5 W / (m·K) (compared to 0.8 W / (m·K) for traditional non-oriented processes, representing an 87.5% improvement);

[0049] Tensile strength: 1420MPa (18% higher than the traditional high-filler process (8wt%), with a retention rate of 95%).

[0050] Example 2: Effect of magnetic field strength on the orientation of graphene sheets with a magnetic coating.

[0051] 1. Device parameters

[0052] Permanent magnet: Surface magnetic intensity 3000mT, adjustable spacing range 20-80mm;

[0053] Filler: Graphene sheets (Fe3O4@GNP, particle size 10μm, filling amount 3wt%) with magnetic coating on the surface.

[0054] 2. Comparative Experiment

[0055] Permanent magnet spacing magnetic field strength Thermal conductivity [W / (m·K)] Tensile strength [MPa] 80mm 60mT 0.9 1405 50mm 100mT 1.3 1412 20mm 200mT 1.0 1398

[0056] Conclusion: The magnetic field strength and thermal conductivity show a trend of first increasing and then decreasing (with appropriate spacing and significant orientation effect), and the mechanical properties remain stable (fluctuation ≤5%).

[0057] Example 3: Verification of the universality of iron-based magnetic ceramic fillers

[0058] 1. Device parameters

[0059] Filler: Iron-based magnetic ceramic particles (Fe3O4@Al2O3, particle size 1μm, filling amount 5wt%);

[0060] Curing conditions: temperature 180℃, time 2 hours, permanent magnet spacing 50mm (magnetic field strength 100mT).

[0061] 2. Performance Data

[0062] Vertical thermal conductivity: 1.2 W / (m·K) (compared to 0.7 W / (m·K) for traditional processes, representing an improvement of 71.4%);

[0063] Flexural strength: 1380 MPa (22% higher than non-oriented samples with the same filler content).

[0064] Note: The device also has a highly efficient orientation effect on iron-based magnetic ceramic fillers, verifying its versatility.

[0065] Comparative Example: Traditional High-Filler Non-Oriented Process

[0066] Filler: Boron nitride (non-magnetic, 8wt% filling amount), with no magnetic field effect;

[0067] Performance: Vertical thermal conductivity 0.8 W / (m·K), tensile strength 1203 MPa (15.2% lower than that of Embodiment 1 of this utility model).

[0068] Conclusion: This device significantly improves thermal conductivity while retaining mechanical properties by using low filler content (4wt% vs 8wt%) and magnetic field orientation, thus solving the pain points of traditional processes.

[0069] This invention achieves efficient orientation of magnetic fillers in carbon fiber composites through structural innovation, solving the problem of balancing thermal conductivity and mechanical properties. It has the advantages of simple process, strong adjustability, and wide adaptability, making it suitable for industrial application.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0071] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An apparatus for inducing orientation of magnetic filler in a carbon fiber composite material, characterized by, include: Permanent magnet assembly: Two permanent magnets of the same size and surface magnetic strength, symmetrically distributed vertically; Perforated stainless steel support frame: located between the two permanent magnets, it is provided with symmetrically distributed circular holes at equal intervals, the circular holes being used to accommodate stainless steel rods; Stainless steel round bars: including at least six bars, which are respectively inserted into the upper, middle and lower circular holes of the perforated stainless steel support frame; Stainless steel rods with circular holes on the top and bottom are used to constrain permanent magnets, so that the two permanent magnets attract each other through magnetic force to form a non-uniform magnetic field. A stainless steel rod inserted through a central circular hole is used to support the carbon fiber composite material mold.

2. The apparatus of claim 1, wherein, The diameter of the stainless steel round bar is smaller than the diameter of the circular hole in the perforated stainless steel support frame.

3. The apparatus of claim 1, wherein, The distance between the permanent magnets on the upper and lower sides of the perforated stainless steel support frame can be adjusted by adjusting the insertion position of the round bar.

4. The apparatus of claim 1, wherein, The permanent magnet is a high-temperature resistant permanent magnet.

5. The apparatus of claim 1, wherein, It also includes a carbon fiber composite mold, which is detachably fixed to a stainless steel round bar in the middle position for holding carbon fiber composite slurry containing magnetic boron nitride filler.

6. The apparatus of claim 1, wherein, The magnetic filler is one or more of the following: boron nitride particles, graphene sheets, or iron-based / nickel-based magnetic ceramic particles with a magnetic coating on their surface.

7. The device of any one of claims 1-6, wherein, The direction of the non-uniform magnetic field is perpendicular to the surface of the carbon fiber composite material.

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