High-reliability military aircraft composite cable and preparation method thereof

Abstract

This invention discloses a high-reliability composite cable for military aircraft and its manufacturing method, comprising an external load-bearing skeleton, an outer protective layer on the surface of the external load-bearing skeleton, an internal conductive core assembly disposed in the internal cavity of the external load-bearing skeleton, and a filling isolation layer between the external load-bearing skeleton and the internal conductive core assembly. This invention proposes a biomimetic skeletal structure, subverting the traditional inside-out layered structure into an outside-in skeleton-medullary cavity structure; the external load-bearing skeleton simultaneously undertakes mechanical protection and electromagnetic shielding functions, while the internal cavity integrates the internal conductive core assembly; PBO fiber, silicon carbide fiber, and OAPS modified cyanate ester work synergistically to achieve a balance of mechanical, thermal, and electrical properties; and an integrated molding process of forming the external load-bearing skeleton, positioning the internal conductive core assembly, and low-pressure injection filling eliminates the multi-layer interface of traditional cables, fundamentally solving the problem of delamination failure; it also possesses ultra-high strength, extreme environmental tolerance, and low-loss signal transmission capability.

Description

Technical Field

[0001] This invention belongs to the field of aviation electrical interconnection technology, specifically relating to a high-reliability composite cable for military aircraft and its preparation method. Background Technology

[0002] Existing military aviation wires face the following technical bottlenecks: 1) Weight and mechanical properties: Traditional copper conductors (such as T2 copper) have high linear density (≥3.5kg / km) and low specific strength; they are prone to fatigue damage under continuous vibration (20-2000Hz, 10gRMS) and high dynamic overload (9g); 2) Environmental adaptability: Conventional polyolefin or fluoroplastic insulation is prone to aging at high temperatures (>200℃) and embrittlement at low temperatures (<-55℃), and it is difficult to maintain performance over a wide temperature range (-70℃~300℃); 3) Electromagnetic compatibility: The shielding effectiveness (SE) of a single-layer shielding structure is limited (usually ≤30dB@1GHz), resulting in poor signal integrity and severe attenuation (≥2dB / m@1GHz) in complex airborne electromagnetic environments. 4) Integration and Reliability: Single-function cables occupy a large space and have high wiring complexity. The interface between the load-bearing layer and the functional layer of existing composite conductors is weak, and they are prone to delamination under impact (peel strength ≤10N / mm), making it difficult to meet the high reliability requirement of ≥5000h in terms of mean time between failures (MTBF). Summary of the Invention

[0003] To address the problems in the prior art, the present invention aims to provide a high-reliability composite cable for military aircraft and its preparation method, which integrates load-bearing, conductivity, insulation, shielding and protection, and also possesses ultra-high strength, extreme environment tolerance and low-loss signal transmission capability.

[0004] To achieve the above objectives and technical effects, the technical solution adopted by this invention is as follows: A high-reliability composite cable for military aircraft includes an external load-bearing frame, an outer protective layer on the surface of the external load-bearing frame, an internal conductive core assembly in the internal cavity of the external load-bearing frame, and a filling isolation layer between the external load-bearing frame and the internal conductive core assembly.

[0005] Furthermore, the outer protective layer is made of amorphous fluorocarbon film with a thickness of 20-30 μm.

[0006] Furthermore, the external load-bearing frame is a porous mesh tube formed using two-dimensional or three-dimensional weaving technology, with a weaving angle of 30°±3° and a porosity of 15-25%.

[0007] Furthermore, the external load-bearing skeleton is made of a cyanate ester resin-based composite material reinforced with a mixture of PBO fibers and silicon carbide fibers, wherein the volume ratio of PBO fibers to silicon carbide fibers is 1-5:1, and cage-like octaaminophenyl silsesquioxane is added to the cyanate ester resin matrix.

[0008] Furthermore, the internal conductive core assembly includes at least one power transmission core and one signal transmission core.

[0009] Furthermore, the power transmission core wire includes a power transmission conductor and a power transmission insulation layer extruded onto its exterior.

[0010] Furthermore, the power transmission conductor is a graphene / nanoporous silver composite conductor, and the power transmission insulation layer is a boron nitride nanotube / polyether ether ketone composite insulation layer, which is coated on the outside of the power transmission conductor by a co-extrusion process.

[0011] Furthermore, the signal transmission core wire includes a signal transmission conductor and a signal transmission insulation layer extruded on its outside. The signal transmission conductor is made of silver-plated copper-clad steel wire, and the signal transmission insulation layer is made of microporous polytetrafluoroethylene with a dielectric constant ≤1.8@10GHz.

[0012] Furthermore, the filling isolation layer is made of thermally conductive silicone rubber-based composite material, with methyl vinyl silicone rubber as the matrix and modified boron nitride microsheets and magnesium hydroxide added.

[0013] This invention also discloses a method for preparing a high-reliability composite cable for military aircraft, characterized by comprising the following steps: The external load-bearing skeleton is formed by using a hybrid PBO fiber and silicon carbide fiber reinforced cyanate ester resin-based composite material and employing two-dimensional or three-dimensional weaving technology. After the external load-bearing frame is formed, an amorphous fluorocarbon film is deposited on the surface of the external load-bearing frame through plasma spraying process to form an outer protective layer. The internal conductive core is positioned in the internal cavity of the external load-bearing frame. Then, thermally conductive silicone rubber-based composite material is injected into the cavity between the external load-bearing frame and the internal conductive core through a low-pressure injection molding process. After vulcanization, it forms a whole.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) Innovative configuration: The "bionic skeleton" structure is proposed, which subverts the traditional layered structure from the inside out and transforms it into a "skeleton-medullary cavity" structure from the outside in; the external load-bearing skeleton undertakes mechanical protection and electromagnetic shielding functions at the same time, and the internal cavity integrates the internal conductive core assembly; 2) External load-bearing skeleton: PBO fiber (ultra-high strength) + silicon carbide fiber (high temperature resistance) + OAPS modified cyanate ester (low dielectric, high Tg), the three work together to achieve a balance of mechanical, thermal and electrical properties; 3) Power transmission conductor: Nanoporous silver (lightweight, high specific surface area) + graphene (low contact resistance, anti-oxidation) work together to achieve ultra-high conductivity and ultra-lightweight; 4) Filler layer: Silicone rubber (elasticity, insulation) + boron nitride (thermal conductivity) + magnesium hydroxide (flame retardant), synergistically achieving "one material with multiple functions"; 5) The integrated molding process of “forming an external load-bearing skeleton → positioning the internal conductive core group → low-pressure injection filling” eliminates the multi-layer interface of traditional cables and fundamentally solves the problem of delamination failure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0016] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0017] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0018] like Figure 1 As shown, this invention discloses a high-reliability composite cable for military aircraft, comprising: Outer protective layer 1, located on the outermost layer, is made of amorphous fluorocarbon film; The external load-bearing skeleton 2 is a porous mesh tube formed by two-dimensional or three-dimensional braiding technology, with a braiding angle of 30°±3° and a porosity of 15-25%. As the main load-bearing structure of the entire cable, the mesh structure provides excellent resistance to radial extrusion and impact while ensuring high axial tensile strength. Internal conductive core assembly: Located in the internal cavity of the external load-bearing frame 2, it includes at least one power transmission core wire 3 and one signal transmission core wire 4, and a certain electrical clearance is maintained between each transmission core wire and between the transmission core wire and the external load-bearing frame 2. Insulating layer 5: Filled between the outer load-bearing frame 2 and the inner conductive core group, as well as between each core wire.

[0019] In some embodiments, an amorphous fluorocarbon film is deposited on the surface of the external load-bearing frame 2 using a plasma spraying process to form an outer protective layer 1 with a thickness of 20-30 μm. The amorphous fluorocarbon film has an extremely low coefficient of friction, excellent chemical corrosion resistance, and hydrophobic and oleophobic properties. As the outermost protective layer, it can effectively resist the erosion of aviation fuel and hydraulic oil, and prevent ice and snow from adhering.

[0020] In some embodiments, the external load-bearing skeleton 2 is made of a cyanate ester resin-based composite material reinforced with a hybrid of PBO fibers and silicon carbide fibers. The volume ratio of PBO fibers to silicon carbide fibers is 1-5:1, preferably 2:1. Cage-like octaaminophenylsilsesquioxane (OAPS) is added to the cyanate ester resin matrix. PBO fibers provide ultra-high tensile strength and modulus, while silicon carbide fibers provide high-temperature stability and compressive strength. The cyanate ester resin has extremely low dielectric loss and moisture absorption. OAPS, as a nano-reinforcing phase, reacts chemically with the cyanate ester resin on its cage-like structure to form an organic-inorganic hybrid cross-linked network, raising the glass transition temperature of the resin matrix to above 350°C, while significantly improving the bond strength at the fiber-resin interface (interfacial shear strength ≥80 MPa). The synergistic effect of these three components gives the external load-bearing skeleton 2 ultra-high strength, high-temperature resistance, and low moisture absorption, enabling it to withstand short-term high-temperature impacts above 300°C.

[0021] In some embodiments, the preparation steps of the external load-bearing frame 2 are as follows: 1) Fiber pretreatment: Mix PBO fiber and silicon carbide fiber at a volume ratio of 1-5:1, immerse in acetone solution, ultrasonically clean for 20-50 min, and vacuum dry at 70-90℃ for 1-5 h to remove surface impurities. 2) Preparation of resin matrix: Take 100 parts of cyanate ester resin, add 1-5 parts of OAPS, and mechanically stir at 70-90℃ for 20-50 minutes to obtain the modified resin matrix. 3) Weaving and forming: The mixed fiber bundles pretreated in step 1) are impregnated with modified resin matrix and woven into porous mesh tubes by a weaving machine; 4) Curing treatment: Place the woven blank into a curing oven, heat it at 1-5℃ / min to 110-140℃ and hold for 0.5-2h, then heat it at 1-5℃ / min to 160-200℃ and hold for 1-5h, then heat it at 1-5℃ / min to 240-260℃ and hold for 1-5h. After natural cooling, the external load-bearing frame 2 is obtained.

[0022] In some embodiments, the power transmission core 3 includes a power transmission conductor 31 and a power transmission insulation layer 32 extruded onto its exterior.

[0023] In some embodiments, the power transmission conductor 31 employs a graphene / nanoporous silver composite conductor. First, a three-dimensional nanoporous silver framework (porosity 60%-70%) is prepared via dealloying. Then, a monolayer of graphene is grown on the surface of the three-dimensional nanoporous silver framework via chemical vapor deposition. The nanoporous silver provides a huge specific surface area and continuous electron transport channels. The graphene coating not only further reduces the interfacial contact resistance but also significantly improves the conductor's oxidation resistance and electromigration resistance. The conductor's conductivity is ≥110% IACS, while its density is only 1 / 3 that of pure copper, achieving a perfect balance between ultra-high conductivity and ultra-light weight.

[0024] In some embodiments, the fabrication steps of the power transmission conductor 31 are as follows: Preparation of three-dimensional nanoporous silver framework: pure silver and pure aluminum are melted into an alloy, and Ag-Al alloy thin strip is prepared by rapid solidification. The strip is immersed in dilute hydrochloric acid solution and etched at 20-30℃ for 1-3 hours to remove aluminum. The strip is washed with deionized water until neutral and then vacuum dried at 30-50℃ for 10-15 hours to obtain a three-dimensional nanoporous silver framework. Graphene coating: The nanoporous silver framework is placed in a chemical vapor deposition furnace, vacuumed, protected with argon gas, heated to 700-900℃ at 8-12℃ / min, and methane is introduced for deposition for 8-15min to grow a single layer of graphene, thus obtaining a graphene / nanoporous silver composite conductor.

[0025] In some embodiments, the power transmission insulation layer 32 is a boron nitride nanotube (BNNT) / polyether ether ketone (PEEK) composite insulation layer, which is coated onto the outside of the power transmission conductor 31 through a co-extrusion process. The boron nitride nanotubes are oriented within the PEEK matrix, forming thermally conductive pathways, increasing the thermal conductivity of the insulation layer by more than 5 times (≥2.5 W / m·K), effectively dissipating heat from the conductor. 100 parts of PEEK and 3-8 parts of BNNT are melt-blended and granulated in a twin-screw extruder, and then coated onto the outside of the graphene / nanoporous silver composite conductor through a co-extrusion process to obtain the power transmission core wire 3.

[0026] In some embodiments, the signal transmission core wire 4 includes a signal transmission conductor 41 and a signal transmission insulation layer 42 extruded onto its exterior.

[0027] In some implementations, the signal transmission conductor 41 is made of silver-plated copper-clad steel wire, providing high strength and good conductivity.

[0028] In some implementations, the signal transmission insulation layer 42 is made of microporous polytetrafluoroethylene with a dielectric constant ≤1.8@10GHz, resulting in extremely low signal transmission loss.

[0029] In some embodiments, the filling and insulating layer 5 is made of a thermally conductive silicone rubber-based composite material, which combines insulation, cushioning, and thermal conductivity. The matrix is ​​methyl vinyl silicone rubber, with modified boron nitride microsheets and magnesium hydroxide added. Functions: The modified boron nitride microsheets form a thermally conductive network within the silicone rubber, efficiently transferring the heat generated by the internal conductive core assembly to the external load-bearing frame 2 and dissipating it; magnesium hydroxide, as an environmentally friendly flame retardant, absorbs heat and decomposes upon contact with fire, releasing water vapor to dilute oxygen. The filling and insulating layer 5 simultaneously achieves four major functions: electrical insulation, thermal management, mechanical cushioning, and flame retardancy, making it an integrated multi-functional layer.

[0030] In some embodiments, 100 parts of methyl vinyl silicone rubber are mixed with 10-50 parts of modified boron nitride micron flakes, 20-40 parts of magnesium hydroxide, and 0.5-2 parts of dicumyl peroxide (DCP). The mixture is then thoroughly mixed on a two-roll mill and passed through a thin mill multiple times to obtain the raw material for preparing the filling isolation layer 5. The external load-bearing frame 2 is fixed to the mold, and the power transmission core wire 3 and signal transmission core wire 4 are positioned. The raw material for preparing the filling isolation layer 5 is preheated to 70-90°C and then injected into the cavity at a low pressure of 0.1-1 MPa and a temperature of 80-120°C. After vulcanization at 140-160°C for 10-30 minutes and 1-5 MPa, the filling isolation layer 5 is formed after demolding.

[0031] This invention also discloses a method for preparing a high-reliability composite cable for military aircraft, comprising the following steps: A cyanate ester resin-based composite material reinforced with a mixture of PBO fiber and silicon carbide fiber is used to form an external load-bearing skeleton 2 using two-dimensional or three-dimensional weaving technology; After the external load-bearing frame 2 is formed, an amorphous fluorocarbon film is deposited on the surface of the external load-bearing frame 2 through plasma spraying process to form the outer protective layer 1. The internal conductive core is positioned in the internal cavity of the external load-bearing frame 2. Then, the thermally conductive silicone rubber-based composite material is injected into the cavity between the external load-bearing frame 2 and the internal conductive core through a low-pressure injection molding process. After vulcanization, it forms a whole.

[0032] Key performance: Mechanical properties: tensile strength ≥2500MPa (based on the entire cable), lateral pressure resistance ≥1500N / 100mm, and impact resistance improved by 200%; Electrical performance: Composite shielding effectiveness ≥80dB@1GHz, signal attenuation ≤0.2dB / m@1GHz; Thermal management performance: Thermal resistance ≤0.5℃·m / W, 60% lower than traditional cables; Lightweight: Linear density ≤1.5kg / km (equivalent current carrying capacity), 50% lower than traditional cables; Reliability: MTBF ≥ 30,000h, service life ≥ 30 years. Example 1

[0033] like Figure 1 As shown, a high-reliability composite cable for military aircraft includes: Outer protective layer 1, located on the outermost layer, is made of amorphous fluorocarbon film; The external load-bearing skeleton 2 is a porous mesh tube formed by three-dimensional braiding technology, with a braiding angle of 30° and a porosity of 20%. As the main load-bearing structure of the entire cable, the mesh structure provides excellent resistance to radial compression and impact while ensuring high axial tensile strength. Internal conductive core assembly: Located in the internal cavity of the external load-bearing frame 2, it includes two power transmission core wires 3 and eight signal transmission core wires 4, and a certain electrical clearance is maintained between each transmission core wire and between the transmission core wires and the external load-bearing frame 2. Insulating layer 5: Filled between the outer load-bearing frame 2 and the inner conductive core group, as well as between each core wire.

[0034] A layer of amorphous fluorocarbon film was deposited on the surface of the external load-bearing skeleton 2 using perfluorodecyl acrylate as a precursor via plasma spraying, forming the outer protective layer 1. The spraying process parameters were: power 40kW, argon flow rate 50L / min, hydrogen flow rate 10L / min, spraying distance 120mm, powder feed rate 20g / min, 3 coats, and a thickness of 25μm. The amorphous fluorocarbon film has an extremely low coefficient of friction, excellent chemical corrosion resistance, and hydrophobic and oleophobic properties. As the outermost protective layer, it can effectively resist the erosion of aviation fuel and hydraulic oil, and prevent ice and snow from adhering.

[0035] The external load-bearing skeleton 2 is made of a cyanate ester resin-based composite material reinforced with a hybrid of PBO and silicon carbide fibers. The volume ratio of PBO fibers to silicon carbide fibers is 2:1. Cage-like octaaminophenylsilsesquioxane (OAPS) is added to the cyanate ester resin matrix. PBO fibers provide ultra-high tensile strength and modulus, while silicon carbide fibers provide high-temperature stability and compressive strength. The cyanate ester resin exhibits extremely low dielectric loss and moisture absorption. OAPS, as a nano-reinforcing phase, reacts chemically with the cyanate ester resin through its cage-like structure, forming an organic-inorganic hybrid cross-linked network. This raises the glass transition temperature of the resin matrix to above 350°C and significantly improves the bond strength at the fiber-resin interface (interfacial shear strength ≥80MPa). The synergistic effect of these three components gives the external load-bearing skeleton 2 ultra-high strength, high-temperature resistance, and low moisture absorption, enabling it to withstand short-term high-temperature impacts above 300°C.

[0036] The preparation steps for the external load-bearing frame 2 are as follows: 1) Fiber pretreatment: PBO fiber and silicon carbide fiber are mixed at a volume ratio of 2:1, immersed in acetone solution, ultrasonically cleaned for 30 min, and vacuum dried at 80℃ for 2 h to remove surface impurities. 2) Preparation of resin matrix: Take 100 parts of cyanate ester resin, add 3 parts of OAPS, and mechanically stir at 80℃ for 30 min to obtain the modified resin matrix; 3) Weaving and forming: The mixed fiber bundles pretreated in step 1) are impregnated with modified resin matrix and woven into porous mesh tubes by a weaving machine at a weaving speed of 0.5m / min and a core mold diameter of 3.5mm. 4) Curing treatment: The woven fabric is placed in a curing oven and heated to 120℃ at 2℃ / min and held for 1h, then heated to 180℃ at 1℃ / min and held for 2h, then heated to 250℃ at 1℃ / min and held for 3h. After natural cooling, the external load-bearing skeleton 2 is obtained, with an outer diameter of 4.2mm, a wall thickness of 0.6mm, and a porosity of 20%.

[0037] The power transmission core wire 3 includes a power transmission conductor 31 and a power transmission insulation layer 32 extruded on its outside.

[0038] The power transmission conductor 31 employs a graphene / nanoporous silver composite conductor. First, a three-dimensional nanoporous silver framework (porosity 60%-70%) is prepared via dealloying. Then, a monolayer of graphene is grown on the surface of the three-dimensional nanoporous silver framework via chemical vapor deposition. The nanoporous silver provides a huge specific surface area and continuous electron transport channels. The graphene coating not only further reduces interfacial contact resistance but also significantly improves the conductor's oxidation resistance and electromigration resistance. The conductor's conductivity is ≥110% IACS, while its density is only 1 / 3 that of pure copper, achieving a perfect balance between ultra-high conductivity and ultra-light weight.

[0039] The fabrication steps of the power transmission conductor 31 are as follows: Preparation of a three-dimensional nanoporous silver framework: Pure silver and pure aluminum were melted into an alloy at an atomic ratio of 30:70, and a 50 μm thick Ag-Al alloy strip was prepared by rapid solidification. The strip was then immersed in a 0.5 mol / L dilute hydrochloric acid solution and etched at 25 °C for 2 h to remove aluminum. After washing with deionized water until neutral, the strip was vacuum dried at 40 °C for 12 h to obtain a three-dimensional nanoporous silver framework with a porosity of 65% and an average pore size of 50 nm. Graphene coating: A nanoporous silver framework was placed in a chemical vapor deposition furnace and evacuated to 10°C. -3 Under argon protection, the temperature was increased to 800℃ at 10℃ / min, and methane (flow rate 20 sccm) was introduced for deposition for 10 min to grow a single layer of graphene, thus obtaining a graphene / nanoporous silver composite conductor.

[0040] The power transmission insulation layer 32 is a composite insulation layer of boron nitride nanotubes (BNNT) / polyether ether ketone (PEEK), which is coated onto the outside of the power transmission conductor 31 through a co-extrusion process. The boron nitride nanotubes are oriented within the PEEK matrix, forming thermally conductive pathways, increasing the thermal conductivity of the insulation layer by more than 5 times (≥2.5W / m·K), effectively dissipating heat from the conductor. 100 parts of PEEK and 5 parts of BNNT are melt-blended and granulated in a twin-screw extruder at 360℃ and 100rpm, and then coated onto the outside of the graphene / nanoporous silver composite conductor through a co-extrusion process at an extrusion temperature of 360℃ and a traction speed of 5m / min, resulting in a power transmission core wire 3 with an insulation layer thickness of 0.15mm and an outer diameter of 0.8mm.

[0041] The signal transmission core wire 4 includes a signal transmission conductor 41 and a signal transmission insulation layer 42 extruded on its outside.

[0042] The signal transmission conductor 41 is made of silver-plated copper-clad steel wire, providing high strength and good conductivity. Seven silver-plated copper-clad steel monofilaments are twisted together on a stranding machine with a twist pitch of 5mm to obtain the signal transmission conductor 41.

[0043] The signal transmission insulation layer 42 is made of microporous polytetrafluoroethylene with a dielectric constant ≤1.8@10GHz, resulting in extremely low signal transmission loss. Two layers of 0.05mm thick and 3mm wide microporous PTFE tape are wrapped around the outside of the signal transmission conductor 41 with a wrapping overlap rate of 50% and a wrapping angle of 30°. The tape is then sintered at 360℃ for 30 minutes to obtain the signal transmission core wire 4 with an outer diameter of 0.4mm.

[0044] The filling and insulating layer 5 is made of thermally conductive silicone rubber-based composite material, combining multiple functions of insulation, cushioning, and thermal conductivity. The matrix is ​​methyl vinyl silicone rubber, with added modified boron nitride microsheets and magnesium hydroxide. Its function is as follows: the modified boron nitride microsheets form a thermally conductive network within the silicone rubber, efficiently transferring the heat generated by the internal conductive core assembly to the external load-bearing frame 2 and dissipating it; magnesium hydroxide, as an environmentally friendly flame retardant, absorbs heat and decomposes upon contact with fire, releasing water vapor to dilute oxygen. The filling and insulating layer 5 simultaneously achieves four major functions: electrical insulation, thermal management, mechanical cushioning, and flame retardancy, making it a multi-functional integrated structure.

[0045] Take 100 parts of methyl vinyl silicone rubber, add 20 parts of commercially available modified boron nitride micron flakes, 30 parts of magnesium hydroxide, and 1 part of dicumyl peroxide (DCP). Mix evenly on a two-roll mill and pass through a thin mill 5 times to obtain the raw material for preparing the filling isolation layer 5. Fix the external load-bearing frame 2 to the mold, position the power transmission core wire 3 and signal transmission core wire 4 (1.2 mm spacing), preheat the raw material for preparing the filling isolation layer 5 to 80°C, and inject it into the cavity at a low pressure of 0.5 MPa and a temperature of 100°C. Then, vulcanize at 150°C for 20 minutes and 5 MPa. After demolding, the filling isolation layer 5 is formed.

[0046] This invention also discloses a method for preparing a high-reliability composite cable for military aircraft, comprising the following steps: A cyanate ester resin-based composite material reinforced with a mixture of PBO fiber and silicon carbide fiber is used to form an external load-bearing skeleton 2 using two-dimensional or three-dimensional weaving technology; After the external load-bearing frame 2 is formed, an amorphous fluorocarbon film is deposited on the surface of the external load-bearing frame 2 through plasma spraying process to form the outer protective layer 1. The internal conductive core is positioned in the internal cavity of the external load-bearing frame 2. Then, the thermally conductive silicone rubber-based composite material is injected into the cavity between the external load-bearing frame 2 and the internal conductive core through a low-pressure injection molding process. After vulcanization, it forms a whole.

[0047] Key performance: Mechanical properties: tensile strength 2800MPa (based on the entire cable), lateral compression resistance 1600N / 100mm; Electrical performance: Composite shielding effectiveness 90dB@1GHz, signal attenuation 0.1dB / m@1GHz; Thermal management performance: Thermal resistance 0.4℃·m / W; Lightweight: linear density 1.4 kg / km (equivalent current carrying capacity); Reliability: MTBF 40000h, service life not less than 30 years.

[0048] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0049] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A high-reliability military aircraft composite cable, characterized by, It includes an external load-bearing frame, the surface of which is provided with an outer protective layer, and an internal conductive core assembly is provided in the internal cavity of the external load-bearing frame. A filling isolation layer is filled between the external load-bearing frame and the internal conductive core assembly.

2. The high-reliability composite cable for military aircraft according to claim 1, characterized in that, The outer protective layer is made of amorphous fluorocarbon film with a thickness of 20-30μm.

3. The high-reliability composite cable for military aircraft according to claim 1, characterized in that, The external load-bearing frame is a porous mesh tube formed using two-dimensional or three-dimensional weaving technology, with a weaving angle of 30°±3° and a porosity of 15-25%.

4. The high-reliability composite cable for military aircraft according to claim 1, characterized in that, The external load-bearing skeleton is made of a cyanate ester resin-based composite material reinforced with a mixture of PBO fiber and silicon carbide fiber, wherein the volume ratio of PBO fiber to silicon carbide fiber is 1-5:1, and cage-like octaaminophenyl silsesquioxane is added to the cyanate ester resin matrix.

5. The high-reliability composite cable for military aircraft according to claim 1, characterized in that, The internal conductive core assembly includes at least one power transmission core and one signal transmission core.

6. The high-reliability composite cable for military aircraft according to claim 5, characterized in that, The power transmission core wire includes a power transmission conductor and a power transmission insulation layer extruded on its outside.

7. The high-reliability composite cable for military aircraft according to claim 6, characterized in that, The power transmission conductor is a graphene / nanoporous silver composite conductor, and the power transmission insulation layer is a boron nitride nanotube / polyether ether ketone composite insulation layer, which is coated on the outside of the power transmission conductor by a co-extrusion process.

8. The high-reliability composite cable for military aircraft according to claim 5, characterized in that, The signal transmission core includes a signal transmission conductor and a signal transmission insulation layer extruded on its outside. The signal transmission conductor is made of silver-plated copper-clad steel wire, and the signal transmission insulation layer is made of microporous polytetrafluoroethylene with a dielectric constant ≤1.8@10GHz.

9. The high-reliability composite cable for military aircraft according to claim 1, characterized in that, The filling and isolation layer is made of thermally conductive silicone rubber-based composite material, with methyl vinyl silicone rubber as the matrix and modified boron nitride microsheets and magnesium hydroxide added.

10. A method for preparing a high-reliability military aircraft composite cable according to any one of claims 1-9, characterized in that, Includes the following steps: The external load-bearing skeleton is formed by using a hybrid PBO fiber and silicon carbide fiber reinforced cyanate ester resin-based composite material and employing two-dimensional or three-dimensional weaving technology. After the external load-bearing frame is formed, an amorphous fluorocarbon film is deposited on the surface of the external load-bearing frame through plasma spraying process to form an outer protective layer. The internal conductive core is positioned in the internal cavity of the external load-bearing frame. Then, thermally conductive silicone rubber-based composite material is injected into the cavity between the external load-bearing frame and the internal conductive core through a low-pressure injection molding process. After vulcanization, it forms a whole.

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