CN111114035A - Carbon fiber sandwich composite material and preparation method and application thereof - Google Patents

Carbon fiber sandwich composite material and preparation method and application thereof Download PDF

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Publication number
CN111114035A
CN111114035A CN201911229294.4A CN201911229294A CN111114035A CN 111114035 A CN111114035 A CN 111114035A CN 201911229294 A CN201911229294 A CN 201911229294A CN 111114035 A CN111114035 A CN 111114035A
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carbon fiber
composite material
sandwich composite
skin
epoxy resin
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孙琳
崔健
冯庆鹏
高玉龙
田爱琴
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CRRC Qingdao Sifang Co Ltd
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CRRC Qingdao Sifang Co Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/14—Layered products comprising a layer of metal next to a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
    • B32B27/281—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42 comprising polyimides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
    • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
    • B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61D—BODY DETAILS OR KINDS OF RAILWAY VEHICLES
    • B61D17/00—Construction details of vehicle bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/10—Inorganic fibres
    • B32B2262/106—Carbon fibres, e.g. graphite fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/212—Electromagnetic interference shielding

Abstract

The invention belongs to the technical field of high-speed train body materials, and particularly relates to a carbon fiber sandwich composite material and a preparation method and application thereof. The carbon fiber sandwich composite material comprises: upper and lower skins and a middle core material; layer structure of the skinThe method comprises the following steps: multilayer carbon fiber plain cloth- (electromagnetic shielding layer-multilayer carbon fiber plain cloth)nN is less than or equal to 10; the core material is a polyimide aerogel plate. According to the invention, by selecting the specific core material and the skin formed by specific compounding, the composite material has the advantages of small density, good environmental adaptability and high electromagnetic shielding performance under the condition of ensuring the binding force; in addition, the material also has the advantages of low room temperature thermal conductivity, good mechanical property, excellent thermal stability, good flame retardant property and the like, is an ideal material for replacing high-speed rail car body aluminum profiles, and can further improve the speed and carrying capacity of iron.

Description

Carbon fiber sandwich composite material and preparation method and application thereof
Technical Field
The invention belongs to the technical field of high-speed train body materials, and particularly relates to a carbon fiber sandwich composite material and a preparation method and application thereof.
Background
At present, a high-speed rail car body is formed by welding aluminum alloy materials, and if a carbon fiber composite material with higher strength and lighter weight is used for replacing an aluminum profile, the speed and carrying capacity of the high-speed rail are further improved; in addition, in order to avoid the interference of external electromagnetic signals on the high-speed rail in the operation process and ensure the grounding smoothly, the substitute material needs to be ensured to have better conductive performance and electromagnetic shielding performance.
The carbon fiber composite material has the characteristic of low weight (compared with an aluminum profile, the weight is at least reduced by 1/4), and is very suitable for manufacturing high-speed rail car bodies; in addition, compared with other composite materials, the carbon fiber composite material also has the following advantages: the designability is strong, and the material can be molded according to different use requirements and structures; the bearing performance is excellent, and the strength of the steel material can reach more than 5 times that of the steel material; the corrosion resistance is good, the corrosion is not easy to occur in the environments of salt mist, acid and alkali, the fatigue resistance is excellent, and the service life is long. By comprehensively considering the characteristics, the carbon fiber composite material is an ideal material for manufacturing the high-speed rail car body.
However, the carbon fiber composite material in the market at present cannot meet the use requirements of high-speed rail bodies, and the performance of the carbon fiber composite material in all aspects needs to be improved.
Disclosure of Invention
In order to overcome the technical problems, the invention provides a carbon fiber sandwich composite material. The carbon fiber sandwich composite material has the advantages of low density, high electromagnetic shielding efficiency, low room-temperature thermal conductivity, good mechanical property, excellent thermal stability (can be stably used at 150 ℃) and good flame retardant property (meets the relevant standard of DIN-5510), and is an ideal material for replacing high-speed rail car body aluminum profiles.
The carbon fiber sandwich composite material comprises: upper and lower skins and a middle core material; wherein the layer structure of the skin comprises: multilayer carbon fiber plain cloth- (electromagnetic shielding layer-multilayer carbon fiber plain cloth)nN is less than or equal to 10; the core material is a polyimide aerogel plate.
According to the invention, the specific core material is selected to be matched with the skin formed by specific compounding, so that the density of the carbon fiber sandwich composite material is remarkably reduced (controlled at 0.2 g/cm) under the condition of ensuring the binding force3Below), the electromagnetic shielding effectiveness and other comprehensive properties are improved, so that the aluminum alloy material of the high-speed rail car body is successfully replaced, and the speed and carrying capacity of the high-speed rail are further improved.
According to some embodiments of the present invention, n in the carbon fiber sandwich composite material may be selected from an integer between 1 and 10, and the specific number of layers may be determined according to actual requirements, for example, 2 layers and 3 layers.
According to some embodiments of the invention, the density of the carbon fiber sandwich composite material is 0.10g/cm3-0.15g/cm3Preferably 0.11g/cm3-0.14g/cm3。
According to some embodiments of the invention, the thickness ratio of the skin to the core material is 1: (2-30), specifically, the proportion of the two can be adjusted according to actual requirements; the total thickness of the obtained carbon fiber sandwich composite material is 5mm-150mm, preferably 15-36 mm.
According to some embodiments of the invention, the thickness ratio of the electromagnetic shielding layer to the multi-layer carbon fiber plain cloth in the skin is 1 (2-20).
According to some embodiments of the invention, the number of layers of the carbon fiber scrim is 4-6, preferably 5. Research shows that the reasonable arrangement of the number of the carbon fiber plain cloth layers can give consideration to the double effects of good designability and good bearing performance of the vehicle body.
According to some embodiments of the invention, the carbon fiber cloth is selected from a T700-3K carbon fiber cloth and/or a T800-3K carbon fiber cloth; wherein, T700 and T800 represent the characteristics of carbon fiber precursors, 3k represents the number of carbon fiber monofilaments in a carbon fiber tow, and the two indexes are basic indexes of carbon fiber cloth. Researches show that the two kinds of carbon fiber cloth not only ensure the performance of the skin, but also are beneficial to saving the cost.
According to some embodiments of the present invention, the material of the electromagnetic shielding layer is selected from one or more of copper, nickel, permalloy, or iron.
The electromagnetic shielding layer is of a grid structure, preferably 90-110 meshes, and preferably 100 meshes.
According to some embodiments of the invention, the layers of the carbon fiber sandwich composite material are bonded by a flame retardant epoxy resin adhesive.
The flame retardant epoxy adhesive includes: flame-retardant epoxy resin and a curing agent; wherein the flame-retardant epoxy resin is selected from tetrachlorobisphenol A epoxy resin, phosphorus-containing bisphenol A epoxy resin and the like, such as GT-807A-1 flame-retardant epoxy resin of a New Corbina procumbens material; the curing agent is selected from a phosphoric anhydride curing agent, a phosphoric hydroxyl curing agent, a phosphoric amino curing agent and the like, for example, GT-807B-1 flame-retardant epoxy resin curing agent of a New Hubbe material.
The mass ratio of the flame-retardant epoxy resin to the curing agent is (1.5-4.5):1, preferably 3: 1. Research shows that the adhesive obtained by selecting proper proportion has better service performance.
According to some embodiments of the invention, the polyimide aerogel sheet has a density of 0.06g/cm3-0.11g/cm3。
Research shows that the polyimide aerogel plate obtained in the range is best in matching with the skin, has the best synergistic effect and is more beneficial to improving the comprehensive performance of the composite material.
The invention also provides a preparation method of the carbon fiber sandwich composite material, which comprises the following steps:
s1, manufacturing a polyimide aerogel plate core material;
s2, manufacturing a carbon fiber composite board skin;
s3, manufacturing the carbon fiber sandwich composite material.
According to some embodiments of the invention, the making of the polyimide aerogel board core comprises: (1) adding diamine into an organic solvent under the nitrogen environment, adding dianhydride after completely dissolving, and continuously stirring until the polycondensation reaction is completely carried out to obtain a solution containing polyamic acid;
(2) adding a dehydrating agent and a catalyst into a solution containing polyamic acid to obtain polyimide;
(3) pouring the solution containing polyimide into a mould, aging the solution at room temperature after the solution is gelled, and soaking the aged gel in a replacement solution for replacement;
(4) and (3) drying the gel by using supercritical carbon dioxide to obtain the polyimide aerogel sandwich board.
In the step (1), the diamine is selected from 4, 4-diaminodiphenyl ether and/or 2, 2-dimethylbenzidine.
In the step (1), the organic solvent is selected from N-methyl pyrrolidone or dimethyl sulfoxide.
In the step (1), the dianhydride is selected from one or more of 3,3,4, 4-biphenyl tetracarboxylic dianhydride, 3,4, 4-benzophenone tetracarboxylic dianhydride or trimethyl glutaric dianhydride.
In the step (2), the dehydrating agent is selected from acetic anhydride.
In the step (2), the catalyst is selected from pyridine.
In the step (3), the replacement liquid is selected from absolute ethyl alcohol or methanol.
Researches show that the polyimide aerogel plate obtained by the method is composed of fibrous aggregates with the diameter of about 20-30nm, and holes with the diameter of 20-100nm are filled around the fibrous aggregates, so that the polyimide aerogel plate is a typical mesoporous material. The polyimide aerogel plate has good mechanical property and low weight, is excellent in bonding property with a skin, and can be used as a core material to manufacture a carbon fiber sandwich material to further reduce the weight of a high-speed rail car body.
According to some embodiments of the invention, the making of the carbon fiber composite panel skin comprises:
(1) bonding the carbon fiber plain cloth and the electromagnetic shielding layer according to a required layer structure by using a flame-retardant epoxy resin adhesive;
(2) and curing and molding the bonded composite material.
Wherein the curing molding operation conditions are as follows: keeping the temperature at 65-75 ℃ for 25-35min, and keeping the temperature at 105-145 ℃ for 1.5-2.5 h; the pressure is maintained at 0-2MPa, preferably 0.4-0.6MPa, throughout the process.
According to some embodiments of the invention, the carbon fiber sandwich composite material is produced by:
(1) polishing the surface of the skin until the surface is rough, and bonding the skin and the core material by using a flame-retardant epoxy resin adhesive;
(2) curing and molding the composite material; and the curing molding conditions are consistent with those in the manufacturing of the carbon fiber composite board skin.
The invention also provides application of the carbon fiber sandwich composite material in the manufacturing field of high-speed rails, aircrafts, missiles or airborne carrier-borne vehicle-mounted shelter.
The invention has the following beneficial effects:
the carbon fiber sandwich composite material has the advantages of low density, good environmental adaptability and high electromagnetic shielding performance; in addition, the material also has the advantages of low thermal conductivity at room temperature, good mechanical property, excellent thermal stability (can be stably used at 150 ℃), good flame retardant property (meets the relevant standard of DIN-5510) and the like, and is an ideal material for replacing high-speed rail vehicle body aluminum profiles.
In addition, according to specific requirements, the formula of the core material and the structure of the skin layer can be adjusted to obtain the carbon fiber sandwich composite material with different thicknesses, densities, mechanical properties and electromagnetic shielding properties, so as to meet the requirements of different application occasions.
Taking a composite material with a thickness of 20mm as an example, the density is about 0.01g/cm3-0.15g/cm3The electromagnetic shielding effectiveness is more than or equal to 40dB, the room-temperature thermal conductivity is about 0.0275W/m.k, the compression Young modulus and the yield strength respectively exceed 25.655MPa and 1.135MPa, the thermal stability is excellent (the material can be stably used at 150 ℃), and the flame retardant property is good (the relevant standard of DIN-5510 is met).
Drawings
FIG. 1 is a scanning electron micrograph of a polyimide aerogel plate obtained in example 1.
FIG. 2 is a scanning electron micrograph of a polyimide aerogel plate obtained in example 2.
FIG. 3 is a scanning electron micrograph of a polyimide aerogel plate obtained in example 3.
FIG. 4 shows the mechanical properties of the carbon fiber/polyimide aerogel sandwich composite materials obtained in examples 1 to 3.
FIG. 5 is a thermogravimetric analysis graph of the carbon fiber/polyimide aerogel sandwich composite obtained in examples 1-3.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
Example 1
The embodiment provides a preparation method of a carbon fiber sandwich composite material, which comprises the following steps:
s1, preparation of polyimide aerogel plate core material
(1) Under the nitrogen environment, 158g of 4, 4-diaminodiphenyl ether is added into 3300mL of N-methylpyrrolidone, the mixture is continuously stirred until the mixture is completely dissolved, 240g of 3,3,4, 4-biphenyltetracarboxylic dianhydride is added, and the mixture is continuously stirred for a certain time until the polycondensation reaction is completely finished after the reactant becomes transparent, so as to obtain a fully reacted polyamic acid solution;
(2) to the polyamic acid solution was added 615mL of acetic anhydride and 525mL of pyridine in moderate excess, and mixed thoroughly to complete the polyimidation of the polyamic acid solution.
(3) Pouring the product polyimide solution into a mold, aging the product polyimide solution at room temperature for 1 day after gelling, soaking the aged gel in 5000mL of absolute ethyl alcohol for sufficient solvent replacement for 3 days, and replacing the ethyl alcohol once a day.
(4) Drying with supercritical carbon dioxide to obtain polyimide aerogel plate;
FIG. 1 is a scanning electron micrograph of a polyimide aerogel plate obtained in example 1.
As can be seen from FIG. 1, the polyimide aerogel plate is composed of fibrous aggregates with a diameter of about 20-30nm, and the peripheries of the fibrous aggregates are filled with holes with a diameter of 20-100nm, and the surface polyimide aerogel core material is a typical mesoporous material, so that the polyimide aerogel plate has good mechanical properties and low weight.
The density of the polyimide aerogel sheet obtained by test example 1 was 0.085g/cm3。
S2, manufacturing of carbon fiber composite board skin
(1) Mixing flame-retardant epoxy resin (a New Corey wood, GT-807A-1 flame-retardant epoxy resin) and flame-retardant epoxy resin curing agent (a New Corey wood, GT-807B-1 flame-retardant epoxy resin curing agent) according to the mass ratio of 3:1, and uniformly stirring.
Simultaneously cutting 20 pieces of T700-3K carbon fiber cloth (wherein T700 represents the characteristics of carbon fiber precursors, 3K represents the number of carbon fiber monofilaments in a carbon fiber tow), and 2 pieces of 100-mesh nickel mesh; wherein the sizes of the nickel net in the length direction and the width direction are respectively 10 cm larger than the sizes of the carbon fiber plain cloth;
(2) uniformly brushing a proper amount of flame-retardant epoxy resin solution on the surface of the carbon fiber plain cloth, laying the carbon fiber plain cloth, and repeating the process to obtain 5 layers of composite carbon fiber plain cloth;
then, coating sufficient flame-retardant epoxy resin solution on two sides of the nickel screen, and placing the nickel screen on the 5 layers of the composite carbon fiber plain cloth;
finally, repeating the compounding process, and laying 5 layers of compounded carbon fiber plain cloth on the nickel net to obtain a carbon fiber composite board;
namely, the layer structure of one skin is as follows: 5 layers of carbon fiber plain cloth, 1 piece of nickel net and 5 layers of carbon fiber plain cloth. The thickness ratio of the electromagnetic shielding layer in the skin to the multi-layer carbon fiber plain cloth is 1: 10.
It should be noted that, because the nickel net is bigger than compound carbon fiber plain cloth size, put carbon fiber plain cloth behind nickel net central point, the nickel net need guarantee at least 50 mm's surplus all around, later use the sealed both sides that extend out of high temperature resistant adhesive tape, epoxy destroys the electric conductive property of nickel net when avoiding curing the shaping.
And finishing another carbon fiber composite board in the same way.
(3) And (3) putting the carbon fiber composite board into an autoclave, and curing and molding the carbon fiber composite board according to the set temperature curve and pressure curve to obtain the carbon fiber composite board skin.
The concrete operation conditions of the curing molding are as follows: keeping the temperature at 70 ℃ for 30min and keeping the temperature at 110 ℃ for 2 h; the pressure was maintained at 0.5MPa throughout the process.
And (3) polishing one surface of each of the two carbon fiber composite board skins by using sand paper to make the surfaces rough, cleaning, then fully wiping the polished surfaces of the carbon fiber skins by using a silane coupling agent, and repeating the process for 3 times after the carbon fiber skins are dried at room temperature.
S3 preparation of carbon fiber sandwich composite material
Coating a proper amount of excessive flame-retardant epoxy resin solution on the polished surface of the carbon fiber composite board skin, coating a proper amount of excessive flame-retardant epoxy resin solution on the surface of the polyimide aerogel board core material, and bonding the three together; the thickness ratio of the skin to the core material is 1: 5; (20 mm core material, 2mm skin, two skins, 4mm total).
And putting the carbon fiber composite plate skin/polyimide aerogel plate core material composite material into an autoclave, and curing and molding the carbon fiber composite plate skin/polyimide aerogel plate core material composite material according to the operation conditions of curing and molding in S2 to obtain the carbon fiber sandwich composite material.
The thickness of the obtained carbon fiber sandwich composite material is 24 mm; the density of the powder was 0.129g/cm3。
Example 2
The embodiment provides a preparation method of a carbon fiber sandwich composite material, which comprises the following steps:
s1, preparation of polyimide aerogel plate core material
(1) Under the nitrogen environment, 179g of 2, 2-dimethylbenzidine is added into 3600mL of N-methylpyrrolidone, 269g of 3,3,4, 4-benzophenonetetracarboxylic dianhydride is added after the 2, 2-dimethylbenzidine is continuously stirred and completely dissolved, and the stirring is continued for a certain time until the polycondensation reaction is completely finished after the reactant becomes transparent, so as to obtain a fully reacted polyamic acid solution.
(2) To the polyamic acid solution was added 615mL of acetic anhydride and 525mL of pyridine in moderate excess, and mixed thoroughly to complete the polyimidation of the polyamic acid solution.
(3) Pouring the product polyimide solution into a mold, aging the product polyimide solution at room temperature for 1 day after gelling, then soaking the aged gel in 5000mL of absolute ethyl alcohol for sufficient solvent replacement for 3 days, and replacing the ethyl alcohol once a day.
(4) And (5) drying by supercritical carbon dioxide to obtain the polyimide aerogel sandwich board.
The density of the polyimide aerogel sheet obtained by test example 2 was 0.097g/cm3。
FIG. 2 is a scanning electron micrograph of a polyimide aerogel plate obtained in example 2.
S2, manufacturing of carbon fiber composite board skin
(1) Mixing flame-retardant epoxy resin (a New Corey wood, GT-807A-1 flame-retardant epoxy resin) and flame-retardant epoxy resin curing agent (a New Corey wood, GT-807B-1 flame-retardant epoxy resin curing agent) according to the mass ratio of 3:1, and uniformly stirring.
Simultaneously cutting 20 pieces of T700-3K carbon fiber cloth and 2 pieces of nickel nets; wherein, the sizes of the nickel net in the length direction and the width direction are 10 cm larger than the sizes of the carbon fiber plain cloth respectively;
(2) uniformly brushing a proper amount of flame-retardant epoxy resin solution on the surface of the carbon fiber plain cloth, then spreading the carbon fiber plain cloth upwards, repeating the process, and bonding 5 layers of carbon fiber plain cloth together;
then putting a nickel net on the paved 5 layers of carbon fiber plain cloth, smearing sufficient flame-retardant epoxy resin solution on two sides of the nickel net, and finally, repeating the process to pave 5 layers of carbon fiber plain cloth;
namely, the layer structure of one skin is as follows: 5 layers of composite carbon fiber plain cloth-nickel net-5 layers of composite carbon fiber plain cloth. The thickness ratio of the electromagnetic shielding layer in the skin to the multi-layer carbon fiber plain cloth is 1: 15.
It should be noted that, because the nickel net is bigger than compound carbon fiber plain cloth size, put carbon fiber plain cloth behind nickel net central point, the nickel net need guarantee at least 50 mm's surplus all around, later use the sealed both sides that extend out of high temperature resistant adhesive tape, epoxy destroys the electric conductive property of nickel net when avoiding curing the shaping.
And finishing the laying of another carbon fiber plate in the same way.
(3) And (3) putting the carbon fiber composite board into an autoclave, and curing and molding the carbon fiber composite board according to the set temperature curve and pressure curve.
The concrete operation conditions of the curing molding are as follows: keeping the temperature at 70 ℃ for 30min and at 110 ℃ for 2 hours; the pressure was maintained at 0.5MPa throughout the process.
And (3) polishing one surface of each of the two carbon fiber skins by using sand paper to make the surfaces rough, cleaning, fully wiping the polished surfaces of the carbon fiber skins by using a silane coupling agent, and repeating the process for 3 times after the carbon fiber skins are dried at room temperature.
S3 preparation of carbon fiber sandwich composite material
Coating a proper amount of flame-retardant epoxy resin solution on the polished surface of the carbon fiber skin, coating a proper amount of flame-retardant epoxy resin solution on the surface of the polyimide aerogel core material, and bonding the carbon fiber skin, the polished surface and the polyimide aerogel core material together; the thickness ratio of the skin to the core material is 1:7.5 (the core material is 30mm, one layer of skin is 2mm, and the total thickness is 4 mm);
and putting the carbon fiber/polyimide aerogel composite material into an autoclave, and curing and molding the carbon fiber/polyimide aerogel composite material according to the previous curing and molding operation conditions to obtain the carbon fiber sandwich composite material.
The obtained carbon fiber sandwich composite material has a thickness of 34mm and a density of 0.114g/cm3。
Example 3
The embodiment provides a preparation method of a carbon fiber sandwich composite material, which comprises the following steps:
s1, preparation of polyimide aerogel plate core material
(1) Under the nitrogen environment, 179g of 2, 2-dimethylbenzidine is added into 3600mL of N-methylpyrrolidone, 269g of 3,3,4, 4-benzophenonetetracarboxylic dianhydride is added after the 2, 2-dimethylbenzidine is continuously stirred and completely dissolved, and the stirring is continued for a certain time until the polycondensation reaction is completely finished after the reactant becomes transparent, so as to obtain a fully reacted polyamic acid solution.
(2) To the polyamic acid solution was added 615mL of acetic anhydride and 525mL of pyridine in moderate excess, and mixed thoroughly to complete the polyimidation of the polyamic acid solution.
(3) Pouring the product polyimide solution into a mold, aging the product polyimide solution at room temperature for 1 day after gelling, then soaking the aged gel in 5000mL of absolute ethyl alcohol for sufficient solvent replacement for 3 days, and replacing the ethyl alcohol once a day.
(4) And (5) drying by supercritical carbon dioxide to obtain the polyimide aerogel sandwich board.
The density of the polyimide aerogel sheet obtained by test example 2 was 0.079g/cm3。
FIG. 3 is a scanning electron micrograph of a polyimide aerogel plate obtained in example 3.
S2, manufacturing of carbon fiber composite board skin
(1) Mixing flame-retardant epoxy resin (a New Corey wood, GT-807A-1 flame-retardant epoxy resin) and flame-retardant epoxy resin curing agent (a New Corey wood, GT-807B-1 flame-retardant epoxy resin curing agent) according to the mass ratio of 3:1, and uniformly stirring.
And simultaneously cutting 30 pieces of T700-3K carbon fiber cloth, 2 pieces of nickel net and 2 pieces of copper net.
(2) Uniformly brushing a proper amount of flame-retardant epoxy resin solution on the surface of the carbon fiber plain cloth, and then laying 5 layers of carbon fiber plain cloth upwards and bonding the carbon fiber plain cloth with the flame-retardant epoxy resin; wherein, the sizes of the nickel net in the length direction and the width direction are 10 cm larger than the sizes of the carbon fiber plain cloth respectively;
then, 1 layer of nickel screen is laid on 5 layers of carbon fiber plain cloth, sufficient flame-retardant epoxy resin solution is smeared on two sides of the nickel screen, and 5 layers of carbon fiber plain cloth are laid on the nickel screen according to the same steps;
then 1 layer of copper mesh is laid on the copper mesh, sufficient flame-retardant epoxy resin solution is smeared on two sides of the copper mesh, and finally 5 layers of carbon fiber plain cloth are laid on the copper mesh.
The obtained skin layer structure is as follows: 5 layers of composite carbon fiber plain cloth, a nickel net, 5 layers of composite carbon fiber plain cloth, a copper net and 5 layers of composite carbon fiber plain cloth. The thickness ratio of the electromagnetic shielding layer in the skin to the multi-layer carbon fiber plain cloth is 1: 10.
And finally, finishing the layering of another carbon fiber plate in the same way.
After the carbon fiber plain cloth is placed between the nickel net and the copper net, the periphery of the nickel net and the copper net needs to be guaranteed to be at least 50mm of surplus, then the two sides of the nickel net extending out are sealed by using a high-temperature-resistant adhesive tape, and the phenomenon that epoxy resin destroys the conductivity of the nickel net during curing forming is avoided.
(3) And (3) putting the carbon fiber composite board into an autoclave, and curing and molding the carbon fiber composite board according to the set temperature curve and pressure curve.
The concrete operation conditions of the curing molding are as follows: keeping the temperature at 70 ℃ for 30min and at 110 ℃ for 2 hours; the pressure was maintained at 0.5MPa throughout the process.
And (3) polishing one surface of each of the two carbon fiber skins by using sand paper to make the surfaces rough, cleaning, fully wiping the polished surfaces of the carbon fiber skins by using a silane coupling agent, and repeating the process for 3 times after the carbon fiber skins are dried at room temperature.
S3 preparation of carbon fiber sandwich composite material
Coating a proper amount of flame-retardant epoxy resin solution on the polished surface of the carbon fiber skin, coating a proper amount of flame-retardant epoxy resin solution on the surface of the polyimide aerogel core material, and bonding the carbon fiber skin, the polished surface and the polyimide aerogel core material together; the thickness ratio of the skin to the core material is 1: 5; (30 mm core material, 3mm skin layer, total 6mm skin layers of upper and lower skin layers);
and putting the carbon fiber/polyimide aerogel composite material into an autoclave, and curing and molding the carbon fiber/polyimide aerogel composite material according to the previous temperature curve and pressure curve.
The obtained carbon fiber sandwich composite material has the thickness of 36mm and the density of 0.117g/cm3。
And (3) performance testing:
1. flame retardant property of carbon fiber/polyimide aerogel sandwich composite material
The carbon fiber/polyimide aerogel sandwich composite material obtained in the examples 1 to 3 is subjected to a flame retardant performance test by adopting DIN 5510-2:2009 standard, and the test results are as follows: the combustion grade is S-3; the smoke grade is SR-2; the dripping grade is ST-2, and the flame retardant performance indexes of the high-speed rail car body are met.
2. Heat insulation performance of carbon fiber/polyimide aerogel sandwich composite material
Excellent thermal insulation performance is another requirement of high-speed railway bodies, and is a disadvantage of metal vehicle bodies, and the thermal conductivity of the carbon fiber/polyimide aerogel sandwich composite material samples obtained in examples 1 to 3 at 24 ℃ is tested in parallel by using a hot wire method, and is respectively 0.0273W/m.k, 0.281W/m.k and 0.0270W/m.k, and the average value (0.0275W/m.k) thereof is used as the thermal conductivity data of the carbon fiber/polyimide aerogel sandwich composite material.
The composite material provided by the invention is used for replacing metal to manufacture the shell of the high-speed rail body, so that the heat-insulating property of the body is greatly improved, and the energy loss in the running process of a train is effectively reduced.
3. Environmental adaptability of carbon fiber/polyimide aerogel sandwich composite material
The environmental adaptability of the carbon fiber/polyimide aerogel sandwich composite material obtained in examples 1-3 was tested by the GJB 150.3A-2009 laboratory environmental test method.
① high temperature test
After the sample is placed in a test box, heating to +150 ℃, keeping the temperature for 24 hours, wherein the temperature change rate is not more than 3 ℃; the temperature in the test chamber was raised to the standard ambient temperature and held for 4 hours, and the sample was taken out.
② low temperature test
After the sample is put into a test box, the temperature is reduced to-55 ℃, the temperature change rate is not more than 3 ℃, and the temperature is kept for 24 hours; the temperature in the test chamber was raised to the standard ambient temperature and held for 4 hours, and the sample was taken out.
③ temperature shock test
High temperature of 150 ℃ and low temperature of-55 ℃; keeping the test temperature for 1 h; temperature conversion time: not more than 5 min; cycle number: 3 times.
④ damp heat test
The procedure was carried out according to standard 7.3 test method for 10 cycles of 24h each.
⑤ mould test
Following standard 7.2 test procedures: 1) temperature: 30 +/-1 ℃; 2) humidity: 95% +/-5%; 3) and (3) test period: 28 days; 4) strain: aspergillus flavus, Aspergillus versicolor, Aspergillus funiculus, Chaetomium globosum and Aspergillus niger.
⑥ salt spray test
Performed according to standard 7.2: the temperature is 35 +/-2 ℃; the concentration of sodium chloride is 5 +/-1%; pH: 6.5-7.2; salt spray settling rate: 1-3mL/80h.cm 2; the spraying method comprises the following steps: alternating; test time: and (6) 96 h. Salt spray and drying were performed alternately for each cycle, 24h spray, 24h drying, and two hour trials were performed.
Test results show that the results of the high-temperature test, the low-temperature test, the temperature impact test, the damp-heat test, the mold test and the salt spray test of the carbon fiber/polyimide aerogel sandwich composite material obtained in the examples 1 to 3 all meet the standard requirements, and the carbon fiber/polyimide aerogel sandwich composite material has good environmental service performance and meets the requirement of high-speed rail on the environmental adaptability of the material.
4. Electromagnetic shielding performance of carbon fiber/polyimide aerogel sandwich composite material
The electromagnetic shielding performance of the material of the present invention is illustrated by taking the carbon fiber/polyimide aerogel composite material without the electromagnetic shielding material (comparative example) and the carbon fiber/polyimide aerogel composite materials obtained in examples 1 to 3 as examples (the shielding effectiveness at each frequency point is measured three times, and the average value is taken and plotted as a graph).
The results of the electromagnetic shielding performance of the composite materials obtained in examples 1 to 3 are shown in Table 1.
TABLE 1
Example 1 Example 2 Example 3 Comparative example
10kHz 39dB 41dB 40dB 5dB
150kHz 47dB 45dB 51dB 13dB
1MHz 51dB 49dB 55dB 19dB
30MHz 68dB 66dB 70dB 53dB
450MHz 70dB 71dB 76dB 57dB
1GHz 72dB 74dB 77dB 60dB
6GHz 75dB 76dB 80dB 63dB
18GHz 74dB 78dB 82dB 68dB
As can be seen from Table 1, the shielding effectiveness of the comparative example carbon fiber sandwich composite material is not less than 53dB at medium and high frequencies (30MHz-18GHz), the requirement of high-speed rail on the electromagnetic shielding performance of the car body material is met, but the problem that the low-frequency band (10kHz, 150KHz and 1MHz) is poor in electromagnetic shielding performance (less than 20dB) exists. This is because the shielding ability of the comparative example composite material is related to the intrinsic properties of the material, such as magnetic permeability and dielectric constant, in the low frequency band (kHz band), and the electrical conductivity is the most important factor for influencing the shielding effectiveness of the comparative example composite material in the middle and high frequency bands (MHz and GHz band). The continuous carbon fiber tows have good electrical conductivity, so that the electromagnetic shielding performance of the composite material manufactured by using the continuous carbon fiber tows in a middle-frequency band and a high-frequency band is ensured, but the electrical conductivity of the carbon fiber material is low, so that the electromagnetic shielding performance of the carbon fiber composite material in the low-frequency band is poor.
The invention adopts a nickel screen method to improve the electromagnetic shielding performance of the composite material, a layer of nickel screen is laid between the first layer and the second layer of composite carbon fiber of the skin (both the upper skin and the lower skin need to be laid), and the rest processes are the same as those of the pure carbon fiber sandwich composite material and are not repeated.
It can be seen that after the nickel mesh is added, the shielding effectiveness of the composite material at low frequency is remarkably improved, while the shielding effectiveness at high frequency is not greatly changed, because the magnetic performance of the carbon fiber tows is very poor, and the amplitude of improving the magnetic performance of the composite material by adding the high-magnetic-permeability material is very large.
5. Mechanical property of carbon fiber/polyimide aerogel sandwich composite material
The compression performance is the most important factor in the mechanical properties of the high-speed rail body material, and the safety and reliability of the train in the running process are determined, so the invention mainly tests and analyzes the compression performance of the carbon fiber sandwich composite material.
FIG. 4 shows the mechanical properties of the carbon fiber/polyimide aerogel sandwich composite materials obtained in examples 1 to 3.
The mechanical property results of the composites obtained in examples 1-3 are shown in Table 2.
TABLE 2
Example 1 Example 2 Example 3
Young's modulus (MPa) 11.48 16.88 11.35
Yield strength (MPa) 0.527 0.690 0.524
In order to ensure the accuracy of the experimental record, each embodiment is subjected to three times of compression tests, and the obtained carbon fiber sandwich composite material is excellent in compression mechanical property and ensures the safety of high-speed rails in the operation process.
6. Thermal stability performance of carbon fiber/polyimide aerogel sandwich composite material
FIG. 5 is a thermogravimetric analysis graph of the carbon fiber/polyimide aerogel sandwich composite obtained in examples 1-3.
As can be seen from FIG. 5, the carbon fiber sandwich composite materials obtained in examples 1-3 had a weight loss of about 1.5 before 150 ℃, which is caused by the material absorbing water in air and being removed, and the physical and chemical properties of the samples at this temperature did not change significantly, indicating that the carbon fiber sandwich composite materials obtained by the method of the present invention can be used normally at 150 ℃.
In order to further verify the long-term service ability of the composite material at 150 ℃, a high-temperature storage experiment is carried out on the composite material according to GBJ150.3A standard, the weight loss of the carbon fiber sandwich composite material obtained in examples 1-3 after being stored for 48 hours in a high-temperature drying environment is less than or equal to 5.3%, and the surface damage ratio is about 2.5% of the total area, which indicates that the carbon fiber sandwich composite material obtained by the method can be used at 150 ℃ and meets the use requirement of a high-speed rail vehicle body.
The results of testing the thermal stability of the composites obtained in examples 1-3 are shown in Table 3.
TABLE 3
Example 1 Example 2 Example 3
Weight loss before 150 deg.C 1.0％ 1.2％ 1.8％
Reducing weight percent after 48 hours at 150 DEG C 4.3％ 4.6％ 5.3％
Surface damage in the proportion of the total area% 1.9％ 2.2％ 2.5％
Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (10)

1. A carbon fiber sandwich composite material is characterized by comprising: upper and lower skins and a middle core material;
wherein the layer structure of the skin comprises: multilayer carbon fiber plain cloth- (electromagnetic shielding layer-multilayer carbon fiber plain cloth)n，n≤10；
The core material is a polyimide aerogel plate.
2. The carbon fiber sandwich composite material as claimed in claim 1, wherein the thickness ratio of the skin to the core material is 1: (2-30);
and/or the total thickness of the obtained carbon fiber sandwich composite material is 5mm-100mm, preferably 15-35 mm;
and/or the thickness ratio of the electromagnetic shielding layer in the skin to the multilayer carbon fiber plain cloth is 1: (2-20);
and/or the number of the carbon fiber plain cloth layers is 4-6, preferably 5.
3. The carbon fiber sandwich composite material according to claim 1 or 2, wherein the carbon fiber cloth is selected from T700-3K carbon fiber cloth and/or T800-3K carbon fiber cloth;
and/or the electromagnetic shielding layer is made of one or more materials selected from copper, nickel, permalloy and iron;
and/or the electromagnetic shielding layer is of a grid structure, preferably 90-110 meshes, and preferably 100 meshes.
4. The carbon fiber sandwich composite material according to any one of claims 1 to 3, wherein the layers of the carbon fiber sandwich composite material are bonded by a flame retardant epoxy resin adhesive; the flame retardant epoxy adhesive includes: flame-retardant epoxy resin and a curing agent;
preferably, the flame-retardant epoxy resin is selected from tetrachlorobisphenol A epoxy resin and/or phosphorus-containing bisphenol A epoxy resin;
and/or, preferably, the curing agent is selected from one or more of a phosphorus-containing anhydride curing agent, a phosphorus-containing hydroxyl curing agent or a phosphorus-containing amino curing agent;
and/or, preferably, the mass ratio of the flame-retardant epoxy resin to the curing agent is (1.5-4.5):1, preferably 3: 1.
5. The carbon fiber sandwich composite material according to any one of claims 1 to 4, wherein the density of the polyimide aerogel board is 0.06g/cm3-0.11g/cm3。
6. The preparation method of the carbon fiber sandwich composite material as claimed in any one of claims 1 to 5, which is characterized by comprising the following steps:
s1, manufacturing a polyimide aerogel plate core material;
s2, manufacturing a carbon fiber composite board skin;
s3, manufacturing the carbon fiber sandwich composite material.
7. The method of claim 6, wherein the preparing of the polyimide aerogel board core material comprises:
(1) adding diamine into an organic solvent under the nitrogen environment, adding dianhydride after completely dissolving, and continuously stirring until the polycondensation reaction is completely carried out to obtain a solution containing polyamic acid;
(2) adding a dehydrating agent and a catalyst into a solution containing polyamic acid to obtain polyimide;
(3) pouring the solution containing polyimide into a mould, aging the solution at room temperature after the solution is gelled, and soaking the aged gel in a replacement solution for replacement;
(4) and (3) drying the gel by using supercritical carbon dioxide to obtain the polyimide aerogel sandwich board.
8. The method for manufacturing the carbon fiber composite board skin according to the claim 6 or 7, wherein the manufacturing of the carbon fiber composite board skin comprises the following steps:
(1) bonding the carbon fiber plain cloth and the electromagnetic shielding layer according to a required layer structure by using a flame-retardant epoxy resin adhesive;
(2) curing and molding the bonded composite material;
wherein the curing molding operation conditions are as follows: keeping the temperature at 65-75 ℃ for 25-35min, and keeping the temperature at 105-145 ℃ for 1.5-2.5 h; the pressure is maintained at 0-2MPa, preferably 0.4-0.6MPa, throughout the process.
9. The preparation method according to any one of claims 6 to 8, wherein the preparation of the carbon fiber sandwich composite material comprises the following steps:
(1) polishing the surface of the skin until the surface is rough, and bonding the skin and the core material by using a flame-retardant epoxy resin adhesive;
(2) curing and molding the composite material; and the curing molding conditions are consistent with those in the manufacturing of the carbon fiber composite board skin.
10. The use of the carbon fiber sandwich composite material of any one of claims 1 to 5 in the field of manufacturing of high-speed rail, aircraft, missile or various types of airborne carrier-borne vehicle-mounted shelter.
CN201911229294.4A 2019-12-04 2019-12-04 Carbon fiber sandwich composite material and preparation method and application thereof Pending CN111114035A (en)

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Publication number Priority date Publication date Assignee Title
CN112197646A (en) * 2020-10-12 2021-01-08 浙江华茂航天科技股份有限公司 Stealth anti-damage shielding shelter
CN117325485A (en) * 2023-11-30 2024-01-02 乌镇实验室 Carbon fiber reinforced polyamide composite material for wind power blade and preparation method thereof

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CN108394148A (en) * 2018-01-03 2018-08-14 山东鲁泰控股集团有限公司 A kind of novel electromagnetic shielding composite material and preparation method thereof

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US20140287641A1 (en) * 2013-03-15 2014-09-25 Aerogel Technologies, Llc Layered aerogel composites, related aerogel materials, and methods of manufacture
CN106866997A (en) * 2017-01-16 2017-06-20 东华大学 A kind of preparation method of nanoporous polyimides aeroge
CN108394148A (en) * 2018-01-03 2018-08-14 山东鲁泰控股集团有限公司 A kind of novel electromagnetic shielding composite material and preparation method thereof

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CN112197646A (en) * 2020-10-12 2021-01-08 浙江华茂航天科技股份有限公司 Stealth anti-damage shielding shelter
CN112197646B (en) * 2020-10-12 2022-11-11 浙江华茂航天科技股份有限公司 Stealth anti-damage shielding shelter
CN117325485A (en) * 2023-11-30 2024-01-02 乌镇实验室 Carbon fiber reinforced polyamide composite material for wind power blade and preparation method thereof
CN117325485B (en) * 2023-11-30 2024-03-08 乌镇实验室 Carbon fiber reinforced polyamide composite material for wind power blade and preparation method thereof

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Application publication date: 20200508