WO2021077669A1

WO2021077669A1 - Anti-explosion and anti-impact gradient composite damping material having negative poisson's ratio, and preparation method therefor

Info

Publication number: WO2021077669A1
Application number: PCT/CN2020/080327
Authority: WO
Inventors: 马衍轩; 李梦瑶; 徐亚茜; 朱鹏飞; 段玉莹; 赵家华; 宋晓辉; 马巧玲
Original assignee: 青岛理工大学
Priority date: 2019-10-25
Filing date: 2020-03-20
Publication date: 2021-04-29
Also published as: KR20220035502A; CN111016318B; CN111016318A; KR102443727B1

Abstract

The present invention provides an anti-explosion and anti-impact gradient composite damping material having a remarkable negative Poisson's ratio effect, and a preparation method therefor. The anti-explosion and anti-impact gradient composite damping material having a negative Poisson's ratio is composed of at least one inner surface viscoelastic layer-inner rigid layer-intermediate elastic layer-outer surface high strength layer layered unit structure. An interface connecting layer is provided between every two adjacent layers of the composite damping material. The intermediate elastic layer comprises a matrix material and a multi-stage heterogeneous fiber prefabricated body provided in the matrix material and having a negative Poisson's ratio effect. The multi-stage heterogeneous fiber prefabricated body is formed by means of warp and weft plain weave of a plurality of multi-stage heterogeneous fibers. The anti-explosion and anti-impact gradient composite damping material having a negative Poisson's ratio of the present invention not only greatly improves the impact damage resistance but also can absorb high impact energy to avoid damage to personnel by rigid impact force in a collision impact process, thereby protecting personal safety to the maximum extent and achieving important social significance.

Description

Anti-explosion and anti-shock negative Poisson's ratio gradient composite damping material and preparation method thereof

Technical field

The invention belongs to the field of disaster prevention and mitigation and protection engineering materials, and relates to an anti-explosion and anti-impact material, and specifically relates to an anti-explosion and anti-impact negative Poisson's ratio gradient composite damping material and a preparation method thereof. The anti-explosion and anti-impact negative Poisson's ratio gradient composite damping material can be applied to buildings such as high-speed train collisions, ship-car collisions, aircraft collisions, ballistic penetration, conventional weapon explosions, gas explosions, and underground integrated pipe gallery gas explosions, as well as traffic engineering Protection and other fields.

Background technique

In recent years, explosions and high-speed collision accidents have occurred frequently at home and abroad, posing serious threats to buildings and even people's lives and property. This is mainly due to the short time of explosion accidents or collision accidents, very large impact loads, and very fast change times, and it is difficult to make effective countermeasures to reduce injuries. Based on this, the current related fields have higher and higher performance requirements for protective materials. Specifically, in the fields of motor vehicle impact, gas explosion in underground integrated pipeline gallery, aircraft impact, ballistic penetration, conventional weapon explosion, gas explosion, traffic engineering, etc., a single homogeneous material is not only heavier, inconvenient to use, and cannot be solved. The contradiction between high strength and high toughness has long been unable to meet people's needs. Ceramic materials have high hardness, high strength, high compressive strength and high temperature resistance. Metals have high toughness and high plastic properties. Therefore, fiber-reinforced composite materials have high impact energy absorption capacity per unit weight or areal density.

The invention patent ZL200610113399.X discloses "fiber-reinforced metal/ceramic laminated composite protective plate". The invention provides a fiber-reinforced metal/ceramic layered composite protective plate, the protective plate has at least one metal layer/fiber layer/ceramic layer sandwich structure, the sandwich structure is at high temperature, through active casting Process, powder sintering process or active metal brazing process to weld the metal layer, fiber layer and ceramic layer together. The protective plate has high hardness, good tear resistance, good toughness, light weight, good protection against high-speed projectile strikes, and can be widely used in body armor, armored vehicles and aircraft that require armor protection. However, the composite material protection board described in the patent still has the following problems: (1) The parameters of the adjacent two layers of the sandwich structure are quite different, which is likely to cause the lack of tight connection and bonding between the layers when subjected to high-speed impact loads. Due to the low strength and the occurrence of delamination, the impact resistance cannot be well realized. (2) The performance of each layer is still insufficient to achieve a large absorption of impact energy. Under the action of high-speed projectiles or explosive shock waves, the effect of absorbing strong dynamic load energy is not ideal.

Summary of the invention

In view of the problems of the anti-explosion and anti-impact composite materials in the prior art, the present invention provides an anti-explosion and anti-impact gradient composite damping material with a significant negative Poisson's ratio effect and a preparation method thereof. The design greatly improves its anti-explosion and impact resistance.

The technical scheme of the present invention:

The anti-explosion and shock-resistant negative Poisson's ratio gradient composite damping material is composed of at least one layered unit structure of inner surface viscoelastic layer-inner rigid layer-middle elastic layer-outer surface high-strength layer. An interface connection layer is provided between two adjacent layers of the composite damping material, and the interface connection layer is phenolic resin, bisphenol A type epoxy resin, silicone resin, alkyd resin, polyester One or more of resins. The intermediate elastic layer includes a base material and a multi-stage heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The matrix material is one or more of epoxy resin, phenolic resin, urea-formaldehyde resin, silicone resin, polyurethane and polyurea added with toughening agent. The multi-stage heterogeneous fiber preform with negative Poisson's ratio effect has 1-4 layers, and the interlayer distance between adjacent multi-stage heterogeneous fiber preforms is 2mm-20mm.

The multi-stage heterogeneous fiber preform is formed by warp and weft plain weaving of several multi-stage heterogeneous fibers. The multi-stage heterogeneous fiber is formed by winding multi-stage auxiliary fibers on the core fiber. The core fiber is a low modulus fiber, and the multi-stage auxiliary fiber is a high modulus fiber with different elastic moduli. The distance between the core fibers of the adjacent multi-stage heterogeneous fibers is 2mm-50mm. The elastic modulus of the low modulus fiber is 50MPa-50GPa; the elastic modulus of the high modulus fiber is ≥50GPa. The auxiliary fiber is wound on the core fiber in stages; the first-level auxiliary fiber in the multi-level auxiliary fiber has an elastic modulus of 50 GPa-90 GPa; the ratio of the elastic modulus of the N-th auxiliary fiber to the N-1-th auxiliary fiber is 1.1-9.6, N=2-7; the diameter ratio of the core fiber and the first-level auxiliary fiber is 1.5-3.0, the diameter ratio of the core fiber and the N-th auxiliary fiber is 2.5-15.0, the N-th auxiliary fiber and the first The diameter ratio of the N-1 auxiliary fiber is 0.5-0.9, and N is 2-7; the helix angle of the first auxiliary fiber is 2°-8°, and the helix angle of the N-th auxiliary fiber is higher than that of the N-1 The auxiliary fiber increases by 3°-15°, the helix angle of the N-th grade auxiliary fiber is 5-60°, and the N is 2-7. The auxiliary fiber adopts a multi-level high-modulus fiber with a gradient distribution of helix angle and elastic modulus, which has excellent durability and high tensile strength, can inhibit the propagation of cracks when microcracks occur, and promote the internal stress of the matrix material It is evenly distributed to improve the compressive strength and impact resistance of the middle elastic layer. As the core fiber, the low modulus fiber has flexibility to improve the tensile, flexural and shear resistance of the fiber mesh fabric structure and the matrix material, and can fully play a role in preventing the rapid damage of the matrix material when macro cracks occur. When the multi-level heterogeneous fiber preform is impacted by a non-parallel external force, the preform tends to be in a straightened state due to the higher elastic modulus and lower elongation of the auxiliary fibers of each level in the preform; The modulus of elasticity is low and the elongation is greatly changed, which tends to be a spiral state. Among them, the diameter of the core fiber is larger than the diameter of the auxiliary fiber. Under stress, the spiral fiber structure appears to widen in the transverse direction, while the fiber preform shows that the mesh warp and weft pores shrink. When the middle elastic body produces cracks, it not only maintains This improves the integrity of the intermediate elastic body and also improves the overall tear resistance and strong dynamic load resistance of the composite damping material.

Preferably, the ratio of the modulus of elasticity of the Nth-level auxiliary fiber to the N-1th-level auxiliary fiber is 1.1-7.5, and N is 2-7; the diameter ratio of the core fiber to the first-level auxiliary fiber is 1.5-2.5, The diameter ratio of the core fiber to the N-th auxiliary fiber is 2.5-10.0, the helix angle of the N-th auxiliary fiber is 10-60°, and the N is 2-7.

Wherein, the low modulus fiber is polyethylene fiber, polyvinyl alcohol fiber, polyvinyl formal fiber, polyvinyl chloride fiber, polypropylene fiber, polyacrylonitrile fiber, polyamide fiber, polyimide fiber, polyvinyl One or more of ester fibers, polyurethane fibers, cellulose fibers, polytetrafluoroethylene fibers, and polyphenylene sulfide fibers; the high modulus fibers are aramid fibers, polybenzimidazole fibers, polybenzobis Oxazole fiber, polyarylate fiber, ultra-high molecular weight polyethylene fiber, glass fiber, carbon fiber, steel fiber, continuous basalt fiber, silicon carbide fiber, magnesium oxide fiber, alumina fiber, silica fiber, quartz fiber, silicic acid One or more of aluminum fiber, graphene fiber and boron fiber.

The inner surface viscoelastic layer is one or more of epoxy resin, phenolic resin, urea-formaldehyde resin, silicone resin, polyurethane and polyurea added with toughening agent.

The internal rigid layer is a ceramic material with an elastic modulus of 220GPa-460GPa, specifically one or more of silicon carbide, boron carbide, silicon nitride, boron nitride, aluminum nitride, aluminum oxide, and zirconia ceramics.

The outer high-strength layer is a metal layer with a plurality of internal recessed hole structures. The inner concave hole is composed of two symmetrically centered regular six-sided terrace structures, the upper and lower ends of the inner concave hole are the bottoms of the regular six-sided terraces, and the tops of the two regular six-sided terraces are connected. The concave angle α where the tops of the two regular six-sided terraces are connected is 120 degrees; the side length of the bottom hexagon of the regular six-sided terraces is a, and the side length d of the top hexagon of the regular six-sided terraces is 0.3a -0.7a, the height h of the inner concave hole is a-2.4a; the volume of a single inner concave hole is 100-1000 mm ³ . The metal is one or more of aluminum, nickel, magnesium, titanium and their alloys. The design of the recessed hole structure greatly improves the storage modulus of the metal, thereby greatly improving its ability to resist and absorb the energy of explosive loads.

The preparation method of the anti-explosion and anti-shock negative Poisson's ratio gradient composite damping material includes the following steps:

(1) Preparation of the inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent to base material is 1.0:0.8-1.0:1.2, and the amount of toughening agent is the quality of the base material And heating to 50°C-80°C until the curing is completed to obtain a viscoelastic layer. The curing agent is one or more of polyamides, polyester resins, glycols, polyols, aromatic amines, and aliphatic amine curing agents; the toughening agent is carboxylated nitrile rubber, poly One or more of vinyl butyral, polyethersulfone, and polyphenylene ether ketone.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.005-Ra0.015.

(3) Preparation of the middle elastic layer:

(a) Processing and preparation of primary heterogeneous fiber embryo structure: according to the helix angle of the primary structure, the high modulus fiber as the primary auxiliary fiber is wound on the low modulus fiber as the core fiber to prepare The first-level heterogeneous fiber embryo structure is obtained.

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the matrix material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 0.1 of the mass of the matrix material %-5.0%, the mass ratio of the curing agent to the base material is 1.0:0.8-1.0:1.2, and the amount of the toughening agent is 5.0%-10.0% of the base material mass; and then the first stage prepared in step (a) The heterogeneous fiber embryo structure is immersed in it, heated to 50°C-80°C, the first-level heterogeneous fiber embryo structure is fully immersed, and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is one or more of titanate coupling agent, aluminate coupling agent, bimetal coupling agent and silane coupling agent; the curing agent is polyamide, polyester resin, One or more of diols, polyols, aromatic amines, and aliphatic amine curing agents; the toughening agent is carboxylated nitrile rubber, polyvinyl butyral, polyethersulfone, polyphenylene One or more of ether ketones.

(c) Processing and preparation of N-level heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the N-level structure to obtain N-grade heterogeneous fiber structure, N is 2-7.

(d) Weaving and preparation of multi-stage heterogeneous fiber preform: the obtained N-stage heterogeneous fiber is woven into a warp-weft plain weave structure according to the warp and weft direction through a warp-weft plain weaving method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and let it stand until solidification is completed to obtain an N-grade heterogeneous fiber preform, with N being 2-7.

(e) Preparation of the middle elastic layer: add the hydroxylated graphene with a mass fraction of 0.2%-2.0% to the matrix material, and ultrasonically disperse it to make it fully dispersed to obtain a modified matrix for use; a layer is laid on the surface of the inner rigid layer Layer a multi-level heterogeneous fiber preform, and then fill, smear or spray the above modified matrix 2mm-20mm, and solidify; repeat the above steps 0-3 times to obtain the intermediate elastic layer.

(4) Processing and preparation of the external high-strength layer: using selective laser sintering method, using UG software to build a three-dimensional metal model of the inner concave hole, the model is converted into STL format and input into the laser powder sintering rapid prototyping system, and the sintering molding is formed with inner concave holes Structure of the metal layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method: Put the layered material into the hot pressing mold of the hot pressing furnace for 3-level vacuuming. After the vacuum degree is extracted, heat at 150℃-220℃ to make the polymer evenly infiltrate the pores and fibers; After the temperature is reached, uniformly pressurize and maintain the pressure for 20min-30min (1～5MPa); ensure that the polymer connecting layer fully penetrates into the porous structure of the concave metal to form a gradient connection; after the hot pressing is completed, the temperature is cooled down, and the resistance is obtained. Explosion-resistant negative Poisson's ratio gradient composite damping material.

The beneficial effects of the present invention:

(1) Compared with the prior art, the anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material of the present invention not only greatly improves the resistance to impact damage, but also can absorb high impact energy and avoid collisions. The rigid impact force in the impact process causes injury to internal personnel, so as to achieve the maximum protection of personal safety, which has important social significance.

(2) The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material of the present invention, the outer high-strength layer is made of metal with an internal concave hole structure, and the middle elastic layer is prefabricated with multi-stage heterogeneous fibers with negative Poisson's ratio effect The inner surface viscoelastic layer is made of viscoelastic polymer materials; and the interface connection layer is set, and the gradient connection between the layers is realized by combining chemical processes, thereby greatly improving its anti-explosion and impact resistance.

(3) Compared with the prior art, the explosion-resistant and impact-resistant composite material of the present invention is additionally provided with an internal rigid layer. The composite of the ceramic material and the fiber layer not only retains the high hardness, high rigidity and high elasticity of the ceramic itself. Modulus overcomes the brittleness of ceramic materials; when the impact load reaches the ceramic layer, it can effectively reduce the continuous impact of the impact load. Compared with the same metal/hybrid fiber reinforced elastic layer/ceramic composite material, the impact resistance can be improved by 268.3 %, to achieve a substantial improvement in impact resistance.

(4) In the preparation method of the composite material of the present invention, the coupling agent is added to the resin to improve the interface structure of fiber and fiber, fiber and metal, ceramic, enhance the bonding force between various interfaces, and make the interface bond Mechanical properties such as strength are improved; at the same time, the addition of tougheners reduces the intermolecular force of the resin, improves the rigidity of the resin and increases its toughness, thereby improving the impact resistance of the resin while ensuring that the fiber layer has a certain degree of elasticity.

Description of the drawings

Figure 1 is a schematic diagram of the structure of a tertiary heterogeneous fiber, in which: a is the core fiber, b1 is the primary auxiliary fiber, b2 is the secondary auxiliary fiber, b3 is the tertiary auxiliary fiber, and θ is the helix angle between the auxiliary fiber and the core fiber , D is the core fiber diameter, d is the auxiliary fiber diameter.

Figure 2 is a schematic diagram of the force and deformation of the tertiary heterogeneous fiber, in which: A1 is the front view of the tertiary heterogeneous fiber in the free initial state, A2 is the radial cross-sectional view of the tertiary heterogeneous fiber in the free initial state, and B1 is the maximum stress state 3. The front view of the third-level heterogeneous fiber, and B2 is the radial section view of the third-level heterogeneous fiber in the maximum stress state.

Figure 3 is a schematic diagram of the fiber warp and weft plain weaving structure in the multi-level heterogeneous fiber preform, where x and y are the distances between the core fibers of the multi-level heterogeneous fiber.

Figure 4 is a schematic diagram of the structure of the inner concave hole, a is the side length of the hexagon at the bottom of the regular six-sided terrace, d is the side length of the hexagon at the top of the regular six-sided terrace, h is the height of the hollow cell, c is the height of the regular hexagonal pyramid, α It is the concave corner at the top of the two regular six-sided terraces.

Figure 5a is a schematic diagram of the structure of a negative Poisson's ratio gradient composite damping material, Figure b is an enlarged view of the cross-sectional part of Figure 5a; among them: 1 is the inner concave metal layer (external high-strength layer), 2 is the negative Poisson's ratio multi-level The heterogeneous fiber preform composite (middle elastic layer), 3 is the ceramic layer (inner rigid layer), 4 is the viscoelastic layer (inner surface viscoelastic layer), and the arrow is the direction of the impact load.

Detailed ways

The present invention will be further described below in conjunction with embodiments.

Example 1:

The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material is composed of a layered unit structure of an inner surface viscoelastic layer-an inner rigid layer-an intermediate elastic layer-an outer high-strength layer. An interface connecting layer is provided between two adjacent layers of the composite damping material, and the interface connecting layer is a phenolic resin added with a coupling agent.

The inner surface viscoelastic layer is epoxy resin added with toughening agent.

The internal rigid layer is silicon carbide ceramic.

The middle elastic layer includes a base material and a secondary heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The base material is a phenolic resin added with a toughening agent. The secondary heterogeneous fiber preform with negative Poisson's ratio effect has two layers, and the interlayer distance between adjacent secondary heterogeneous fiber preforms is 15 mm. The secondary heterogeneous fiber preform with negative Poisson's ratio effect is flat-woven by several secondary heterogeneous fibers in warp and weft. The secondary heterogeneous fiber is formed by winding multi-level auxiliary fibers on a core fiber; the core fiber is a polyester fiber; a fiber bundle with a polyester fiber diameter of 450 μm has an elongation at break of 18% and a modulus of elasticity. It is 13.5GPa, the density is 1.38g/cm ³ , and it has excellent acid and alkali resistance. The first-level auxiliary fiber is aramid fiber, the elastic modulus is 50 GPa, the diameter is 150 μm, and the helix angle is 8°; the second-level auxiliary fiber is aluminum silicate fiber, the elastic modulus is 480 GPa, and the diameter is 75 μm, The helix angle is 20°. The distance between the core fibers of adjacent secondary heterogeneous fibers is 15 mm.

The outer high-strength layer is a metal layer with a plurality of internal recessed hole structures. The inner concave hole is composed of two symmetrically centered regular six-sided terrace structures, the upper and lower ends of the inner concave hole are the bottoms of the regular six-sided terraces, and the tops of the two regular six-sided terraces are connected. The concave angle α at the top of the two regular six-sided terraces is 120 degrees; the side length of the bottom hexagon of the regular six-sided terrace is a (a=2.7mm), and the top hexagon of the regular six-sided terrace is The side length d is 0.7a, the height h of the inner recessed hole is a; the volume of a single inner recessed hole is ¹⁰³ mm 3; the metal is aluminum alloy.

(1) Preparation of inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent and base material is 1.0:0.8, and the amount of toughening agent is 5.0% of the mass of the base material, Heat to 50°C until curing is completed to obtain a viscoelastic layer. The curing agent is polyamide; the toughening agent is carboxyl nitrile rubber.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.005.

(3) Preparation of the middle elastic layer:

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the base material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 1.0 of the mass of the base material %, the mass ratio of the curing agent to the matrix material is 1.0:0.8, and the amount of toughening agent is 5.0% of the matrix material mass; then the primary heterogeneous fiber embryo structure prepared in step (a) is immersed in it and heated to At 50°C, the first-level heterogeneous fiber embryo structure is fully immersed, and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is a titanate coupling agent; the curing agent is a polyamide; and the toughening agent is a carboxyl nitrile rubber.

(c) Processing and preparation of secondary heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the secondary structure to obtain Secondary heterogeneous fiber structure.

(d) Weaving and preparation of multi-stage heterogeneous fiber preform: the obtained secondary heterogeneous fiber is woven into a warp and weft plain weave structure according to the warp and weft direction through a warp and weft plain weaving method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and stand still until curing is completed to obtain a secondary heterogeneous fiber preform.

(e) Preparation of the middle elastic layer: add 0.4% hydroxylated graphene to the matrix material, ultrasonically disperse it to make it fully dispersed, and obtain a modified matrix for use; laying a multi-level layer on the surface of the inner rigid layer The heterogeneous fiber preform is then filled, smeared or sprayed with 20 mm of the above modified matrix, and cured; the above steps are repeated once to obtain the intermediate elastic layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method: Put the layered material into the hot pressing mold of the hot pressing furnace to perform 3-level vacuuming. After the vacuum degree is extracted, heat at 150°C; when the temperature is reached, perform uniform pressure and hold pressure for 20 minutes (1MPa); After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.

Example 2:

The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material is composed of a layered unit structure of an inner surface viscoelastic layer-an inner rigid layer-an intermediate elastic layer-an outer high-strength layer. An interface connecting layer is arranged between two adjacent layers of the composite damping material, and the interface connecting layer is a bisphenol A epoxy resin with a coupling agent.

The inner surface viscoelastic layer is a phenolic resin added with a toughening agent.

The internal rigid layer is boron carbide ceramic.

The intermediate elastic layer includes a base material and a tertiary heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The base material is epoxy resin added with toughening agent. The tertiary heterogeneous fiber preform with negative Poisson's ratio effect has 3 layers, and the interlayer distance between adjacent tertiary heterogeneous fiber preforms is 5 mm. For a tertiary heterogeneous fiber preform with a negative Poisson's ratio effect, the distance between core fibers of adjacent tertiary heterogeneous fibers is 5 mm. The low modulus fiber is polyethylene fiber; the fiber bundle with a diameter of 380 μm has an elastic modulus of 4 GPa, a breaking elongation of 15%, and a density of 0.91 g/cm ³ . The first-level auxiliary fiber is aramid fiber, the elastic modulus is 85 GPa, the diameter is 243 μm, and the helix angle is 7°; the second-level auxiliary fiber is ultra-high molecular weight polyethylene fiber, the elastic modulus is 130 GPa, and the diameter is 149μm, the helix angle is 20°; the third-level auxiliary fiber is steel fiber and carbon fiber, wherein the elastic modulus of steel fiber is 205GPa, the elastic modulus of carbon fiber is 205GPa, and the diameter of steel fiber and carbon fiber is 141μm, The helix angles of carbon fiber and steel fiber are both 35°.

The outer surface high-strength layer is a metal layer with a plurality of inner concave hole structures; the inner concave hole is composed of two centrally symmetric regular six-sided terrace structures, and the upper and lower ends of the inner concave hole are regular six-sided ladders. The bottom of the platform is connected with the tops of the two regular six-sided terraces. The concave angle α at the top of the two regular six-sided terraces is 120 degrees; the side length of the bottom hexagon of the regular six-sided terrace is a (a=3.0mm), and the top hexagon of the regular six-sided terrace is The side length d is 0.4a, the height h of the inner recessed hole is 2.1a; the volume of a single inner recessed hole is 142 mm ³ ; the metal is aluminum.

(1) Preparation of inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent to base material is 1.0:0.9, and the amount of toughening agent is 6.0% of the mass of the base material, Heat to 55°C until curing is complete to obtain a viscoelastic layer. The curing agent is polyester resin; the toughening agent is polyvinyl butyral.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.007.

(3) Preparation of the middle elastic layer:

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the matrix material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 1.5 of the mass of the matrix material %, the mass ratio of the curing agent to the matrix material is 1.0:0.9, and the amount of the toughening agent is 6.0% of the matrix material mass; then the primary heterogeneous fiber embryo structure prepared in step (a) is immersed in it and heated to At 55°C, the first-level heterogeneous fiber embryo structure is fully immersed and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is an aluminate coupling agent; the curing agent is a polyester resin; and the toughening agent is polyvinyl butyral.

(c) Processing and preparation of tertiary heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the tertiary structure to obtain Tertiary heterogeneous fiber structure.

(d) Woven preparation of multi-stage heterogeneous fiber preform: the obtained tertiary heterogeneous fiber is woven into a warp and weft plain weaving structure according to the warp and weft direction through a warp and weft plain weaving method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and stand still until curing is completed to obtain a tertiary heterogeneous fiber preform.

(e) Preparation of the middle elastic layer: add 0.6% hydroxylated graphene to the matrix material, ultrasonically disperse it to make it fully dispersed, and obtain a modified matrix for use; laying a multi-level layer on the surface of the inner rigid layer The heterogeneous fiber preform is then filled, smeared or sprayed with 15mm of the above modified matrix, and cured; the above steps are repeated twice to obtain the intermediate elastic layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method, put the layered material into the hot pressing mold of the hot pressing furnace for 3-level vacuum, after the vacuum degree is extracted, heat at 160℃; when the temperature is reached, apply uniform pressure and hold the pressure for 22min (2MPa); After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.

Example 3:

The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material is composed of a layered unit structure of an inner surface viscoelastic layer-an inner rigid layer-an intermediate elastic layer-an outer high-strength layer. An interface connection layer is provided between two adjacent layers of the composite damping material, and the interface connection layer is a silicone resin added with a coupling agent.

The inner surface viscoelastic layer is a urea-formaldehyde resin added with a toughening agent.

The internal rigid layer is silicon nitride ceramic.

The middle elastic layer includes a base material and a four-stage heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The base material is a silicone resin added with a toughening agent. The fourth-level heterogeneous fiber preform with negative Poisson's ratio effect has 4 layers, and the interlayer distance between adjacent fourth-level heterogeneous fiber preforms is 4 mm. For the fourth-level heterogeneous fiber preform with a negative Poisson's ratio effect, the distance between the core fibers of adjacent fourth-level heterogeneous fibers is 25 mm. The low modulus fiber is polyphenylene sulfide fiber; a fiber bundle with a diameter of 415 μm has an elastic modulus of 5.94 GPa and a breaking elongation of 30%. The first-level auxiliary fiber is polyarylate fiber, the elastic modulus is 50 GPa, the diameter is 272 μm, and the helix angle is 6°; the second-level auxiliary fiber is polybenzodiaxazole fiber, the elastic modulus is 56 GPa, The diameter is 223μm and the helix angle is 11°; the third-level auxiliary fiber is ultra-high molecular weight polyethylene fiber, the elastic modulus is 65GPa, the diameter is 145μm, and the helix angle is 18°; the fourth-level auxiliary fiber is oxidized Aluminum fiber, elastic modulus is 455GPa, diameter is 125μm, helix angle is 31°.

The outer high-strength layer is a metal layer with a plurality of internal recessed hole structures. The inner concave hole is composed of two symmetrically centered regular six-sided terrace structures, the upper and lower ends of the inner concave hole are the bottoms of the regular six-sided terraces, and the tops of the two regular six-sided terraces are connected. The concave angle α at the top of the two regular six-sided terraces is 120 degrees; the side length of the bottom hexagon of the regular six-sided terrace is a (a=4.0mm), and the top hexagon of the regular six-sided terrace is The side length d is 0.5a, the height h of the inner recessed hole is 1.7a; the volume of a single inner recessed hole is 336 mm ³ ; the metal is nickel.

(1) Preparation of inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent to base material is 1.0:1.0, the amount of toughening agent is 7.0% of the mass of the base material, Heat to 60°C until curing is completed to obtain a viscoelastic layer. The curing agent is polyamide; the toughening agent is polyethersulfone.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.009.

(3) Preparation of the middle elastic layer:

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the matrix material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 2.0 of the mass of the matrix material %, the mass ratio of the curing agent to the matrix material is 1.0:1.0, and the amount of the toughening agent is 7.0% of the mass of the matrix material; then the primary heterogeneous fiber embryo structure prepared in step (a) is immersed in it and heated to At 60°C, the first-level heterogeneous fiber embryo structure is fully immersed, and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is a bimetallic coupling agent; the curing agent is polyamide; and the toughening agent is polyethersulfone.

(c) Processing and preparation of quaternary heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the quaternary structure to obtain Grade four heterogeneous fiber structure.

(d) Weaving and preparation of multi-stage heterogeneous fiber preform: the obtained fourth-stage heterogeneous fiber is woven into a warp and weft plain weaving structure according to the warp and weft direction through a warp and weft plain weaving method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and let it stand until solidification is completed to obtain a fourth-grade heterogeneous fiber preform.

(e) Preparation of the middle elastic layer: add 0.8% mass fraction of hydroxylated graphene to the matrix material, ultrasonically disperse it to make it fully dispersed, and obtain a modified matrix for use; laying a multi-level layer on the surface of the inner rigid layer The heterogeneous fiber preform is then filled, smeared or sprayed with 5 mm of the above modified matrix, and cured; the above steps are repeated 3 times to obtain the intermediate elastic layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method: Put the layered material into the hot pressing mold of the hot pressing furnace for 3-level vacuuming. After the vacuum degree is extracted, heat it at 170°C; when the temperature is reached, apply uniform pressure and hold the pressure for 25min (5MPa); After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.

Example 4:

The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material is composed of a layered unit structure of an inner surface viscoelastic layer-an inner rigid layer-an intermediate elastic layer-an outer high-strength layer. An interface connection layer is provided between two adjacent layers of the composite damping material, and the interface connection layer is an alkyd resin added with a coupling agent.

The inner surface viscoelastic layer is a silicone resin added with a toughening agent.

The internal rigid layer is boron nitride ceramic.

The intermediate elastic layer includes a base material and a five-stage heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The matrix material is a urea-formaldehyde resin added with a toughening agent. The five-level heterogeneous fiber preform with negative Poisson's ratio effect has two layers, and the interlayer distance between adjacent five-level heterogeneous fiber preforms is 8 mm. For the fifth-level heterogeneous fiber preform with a negative Poisson's ratio effect, the distance between the core fibers of adjacent fifth-level heterogeneous fibers is 30 mm. The low modulus fiber is polyester fiber; polyester fiber: the diameter is 670 μm, the density is 1.34 g/cm ³ , the elastic modulus is 13.55 GPa, and the elongation at break is 20%, and it is a flexible chain fiber. The first-level auxiliary fiber is aramid fiber, the elastic modulus is 50 GPa, the diameter is 230 μm, and the helix angle is 7°; the second-level auxiliary fiber is quartz fiber, the elastic modulus is 78 GPa, the diameter is 125 μm, and the helix angle Is 10°, the third-level auxiliary fiber is polyarylate fiber, the elastic modulus is 87 GPa, the diameter is 90 μm, and the helix angle is 24°, the fourth-level auxiliary fiber is basalt fiber, and the elastic modulus is 111 GPa, The diameter is 77 μm, and the helix angle is 35°; the fifth-level auxiliary fiber is alumina fiber, the elastic modulus is 459 GPa, the diameter is 71 μm, and the helix angle is 50°.

The outer high-strength layer is a metal layer with a plurality of internal recessed hole structures. The inner concave hole is composed of two symmetrically centered regular six-sided terrace structures, the upper and lower ends of the inner concave hole are the bottoms of the regular six-sided terraces, and the tops of the two regular six-sided terraces are connected. The concave angle α at the top of the two regular six-sided terraces is 120 degrees; the side length of the bottom hexagon of the regular six-sided terrace is a (a=5.0mm), and the top hexagon of the regular six-sided terrace is The side length d is 0.6a, the height h of the inner recessed hole is 1.35a; the volume of a single inner recessed hole is 657 mm ³ ; the metal is a nickel alloy.

(1) Preparation of inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent and base material is 1.0:1.1, the amount of toughening agent is 8.0% of the mass of the base material, Heat to 65°C until curing is complete to obtain a viscoelastic layer. The curing agent is polyetheramine; the toughening agent is polyphenylene ether ketone.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.011.

(3) Preparation of the middle elastic layer:

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the base material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 4.0 of the mass of the base material %, the mass ratio of the curing agent to the matrix material is 1.0:1.1, and the amount of the toughening agent is 8.0% of the matrix material mass; then the primary heterogeneous fiber embryo structure prepared in step (a) is immersed in it and heated to At 65°C, the first-level heterogeneous fiber embryo structure is fully immersed and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is a silane coupling agent; the curing agent is polyetheramine; and the toughening agent is polyphenylene ether ketone.

(c) Processing and preparation of five-level heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the five-level structure to obtain Five-grade heterogeneous fiber structure.

(d) Weaving and preparation of multi-stage heterogeneous fiber preform: The obtained five-stage heterogeneous fiber is woven into a warp and weft plain weaving structure according to the warp and weft direction through a warp and weft plain weaving method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and let it stand until solidification is completed to obtain a five-level heterogeneous fiber preform.

(e) Preparation of the middle elastic layer: adding 1.2% mass fraction of hydroxylated graphene to the matrix material, ultrasonically dispersing to make it fully dispersed, to obtain a modified matrix for use; laying a multi-level layer on the surface of the inner rigid layer The heterogeneous fiber preform is then filled, smeared or sprayed with 10 mm of the above modified matrix, and cured; repeat the above steps once to obtain the intermediate elastic layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method: Put the layered material into the hot pressing mold of the hot pressing furnace to perform 3-level vacuuming. After the vacuum degree is extracted, heat it at 180°C; when the temperature is reached, perform uniform pressure and pressure hold for 30 minutes (1MPa); After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.

Example 5:

The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material is composed of a layered unit structure of an inner surface viscoelastic layer-an inner rigid layer-an intermediate elastic layer-an outer high-strength layer. An interface connecting layer is arranged between two adjacent layers of the composite damping material, and the interface connecting layer is a polyester resin added with a coupling agent.

The inner surface viscoelastic layer is polyurethane added with toughening agent.

The internal rigid layer is aluminum nitride ceramic.

The intermediate elastic layer includes a base material and a six-stage heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The base material is epoxy resin added with toughening agent. The six-level heterogeneous fiber preform with negative Poisson's ratio effect has three layers, and the interlayer distance between adjacent six-level heterogeneous fiber preforms is 6 mm. For the sixth-level heterogeneous fiber preform with a negative Poisson's ratio effect, the distance between the core fibers of adjacent sixth-level heterogeneous fibers is 40 mm. The low modulus fiber is polyvinyl alcohol fiber; polyamide fiber: long fiber, diameter is 485 μm, elongation at break is 24%, elastic modulus is 5.23 GPa, and density is 1.16 g/cm ³ . The first-level auxiliary fiber is aramid fiber, the elastic modulus is 72 GPa, the diameter is 285 μm, and the helix angle is 7°; the second-level auxiliary fiber is polyarylate fiber, the elastic modulus is 120 GPa, and the diameter is 226 μm, The helix angle is 15°; the third-level auxiliary fiber is steel fiber, the elastic modulus is 210 GPa, the diameter is 180 μm, and the helix angle is 25°; the fourth-level auxiliary fiber is silicon carbide fiber, and the elastic modulus is 290 GPa , The diameter is 142μm, the helix angle is 34°; the fifth-level auxiliary fiber is alumina fiber, the elastic modulus is 373GPa, the diameter is 114μm, and the helix angle is 40°; the sixth-level auxiliary fiber is aluminum silicate The fiber has an elastic modulus of 481 GPa, a diameter of 100 μm, and a helix angle of 50°.

The outer high-strength layer is a metal layer with a plurality of internal recessed hole structures. The inner concave hole is composed of two symmetrically centered regular six-sided terrace structures, the upper and lower ends of the inner concave hole are the bottoms of the regular six-sided terraces, and the tops of the two regular six-sided terraces are connected. The concave angle α at the top of the two regular six-sided terraces is 120 degrees; the side length of the bottom hexagon of the regular six-sided terrace is a (a=6.0mm), and the top hexagon of the regular six-sided terrace is The side length d is 0.7a, the height h of the inner recessed hole is a; the volume of a single inner recessed hole is 578 mm ³ ; the metal is a magnesium alloy.

(1) Preparation of inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent and base material is 1.0:1.2, the amount of toughening agent is 9.0% of the mass of the base material, Heat to 70°C until curing is completed to obtain a viscoelastic layer. The curing agent is ethylene glycol; the toughening agent is carboxyl nitrile rubber.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.013.

(3) Preparation of the middle elastic layer:

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the matrix material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 5.0 of the mass of the matrix material %, the mass ratio of the curing agent to the matrix material is 1.0:1.2, and the amount of the toughening agent is 9.0% of the mass of the matrix material; then the primary heterogeneous fiber embryo structure prepared in step (a) is immersed in it and heated to At 70°C, the first-level heterogeneous fiber embryo structure is fully immersed and then the curing system is pulled out, and it is allowed to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is a titanate coupling agent; the curing agent is ethylene glycol; and the toughening agent is carboxyl nitrile rubber.

(c) Processing and preparation of the six-level heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the six-level structure to obtain Six-level heterogeneous fiber structure.

(d) Weaving and preparation of multi-stage heterogeneous fiber preform: The obtained sixth-stage heterogeneous fiber is woven into a warp-weft flat-weave structure according to the warp and weft direction through a warp-weft flat-weave method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and let it stand until the curing is completed to obtain a six-level heterogeneous fiber preform.

(e) Preparation of the middle elastic layer: add 1.6% hydroxylated graphene to the matrix material, and ultrasonically disperse it to make it fully dispersed to obtain a modified matrix for use; laying a multi-level layer on the surface of the inner rigid layer The heterogeneous fiber preform is then filled, smeared or sprayed with 8 mm of the above modified matrix, and cured; repeat the above steps once to obtain the intermediate elastic layer.

(4) Processing and preparation of the external high-strength layer: using selective laser sintering method, using UG software to build a three-dimensional metal model of the inner concave hole, the model is converted into STL format and input into the laser powder sintering rapid prototyping system, and the sintered molding is obtained with inner concave Structure of the metal layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method: Put the layered material into the hot pressing mold of the hot pressing furnace and perform 3-level vacuuming. After the vacuum is drawn, heat at 200°C; after the temperature is reached, apply uniform pressure and hold the pressure for 20 minutes (5MPa); After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.

Example 6:

The inner surface viscoelastic layer is polyurea added with a toughening agent.

The internal rigid layer is alumina ceramic.

The intermediate elastic layer includes a base material and a seven-stage heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the base material. The matrix material is polyurea added with a toughening agent. The seven-level heterogeneous fiber preform with a negative Poisson's ratio effect has 4 layers, and the interlayer distance between the adjacent seven-level heterogeneous fiber preforms is 20 mm. For the seventh-level heterogeneous fiber preform with a negative Poisson's ratio effect, the distance between the core fibers of adjacent seventh-level heterogeneous fibers is 50 mm. The low modulus fiber is a polyimide fiber; wherein the elastic modulus is 12 GPa, the density is 2.35 g/cm ³ , the diameter is 600 μm, and the elongation at break is 29%. The first-level auxiliary fiber is alkali-resistant glass fiber, the elastic modulus is 74 GPa, the diameter is 305 μm, and the helix angle is 5°; the second-level auxiliary fiber is ultra-high molecular weight polyethylene fiber, the elastic modulus is 100 GPa, and the diameter is 5°. Is 200μm and the helix angle is 14°; the third-level auxiliary fiber is silicon carbide fiber, the modulus of elasticity is 174GPa, the diameter is 152μm, and the helix angle is 24°; the fourth-level auxiliary fiber is steel fiber, the elastic modulus The amount is 202 GPa, the diameter is 124 μm, and the helix angle is 33°; the fifth-level auxiliary fiber is carbon fiber, the elastic modulus is 245 GPa, the diameter is 102 μm, and the helix angle is 40°; the sixth-level auxiliary fiber is alumina The fiber has an elastic modulus of 351 GPa, a diameter of 76 μm, and a helix angle of 50°; the seventh-level auxiliary fiber is a silicon carbide fiber with an elastic modulus of 462 GPa, a diameter of 41 μm, and a helix angle of 60°.

The outer high-strength layer is a metal layer with a plurality of internal recessed hole structures. The inner concave hole is composed of two symmetrically centered regular six-sided terrace structures, the upper and lower ends of the inner concave hole are the bottoms of the regular six-sided terraces, and the tops of the two regular six-sided terraces are connected. The concave angle α at the top of the two regular six-sided terraces is 120 degrees; the side length of the bottom hexagon of the regular six-sided terrace is a (a=7mm), and the sides of the top hexagon of the regular six-sided terrace are The length d is 0.5a, the height h of the inner recessed hole is 1.7a; the volume of a single inner recessed hole is 920 mm ³ ; the metal is a titanium alloy.

(1) Preparation of the inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent to base material is 1.0:0.9, and the amount of toughening agent is 10.0% of the mass of the base material, Heat to 80°C until curing is completed to obtain a viscoelastic layer. The curing agent is hexamethylene diamine; the toughening agent is polyvinyl butyral.

(2) Processing and preparation of the internal rigid layer: the roughness of the ceramic surface is improved, and the laser etching technology is used to irradiate the ceramic with high-energy laser to melt and re-quench the surface, thereby forming scattered small pits to increase the ceramic's The bonding area, mechanical mating force, and roughness are maintained at Ra0.015.

(3) Preparation of the middle elastic layer:

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the base material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 3.0 of the mass of the base material %, the mass ratio of the curing agent to the matrix material is 1.0:0.9, and the amount of the toughening agent is 7.0% of the matrix material mass; then the primary heterogeneous fiber embryo structure prepared in step (a) is immersed in it and heated to At 80°C, the first-level heterogeneous fiber embryo structure is fully immersed, and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained. The coupling agent is a silane coupling agent; the curing agent is hexamethylene diamine; and the toughening agent is polyvinyl butyral.

(c) Processing and preparation of the seven-level heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the seventh-level structure to obtain Seven-level heterogeneous fiber structure.

(d) Knitting and preparation of multi-stage heterogeneous fiber preform: the obtained seven-stage heterogeneous fiber is woven into a warp-weft flat-weave structure according to the warp and weft direction through a warp-weft flat-weave method, and then the solidification system described in step (b) is fully Coating on all the warp and weft junctions of the warp and weft plain weave structure, and let it stand until it is cured to obtain a seven-grade heterogeneous fiber preform.

(e) Preparation of the middle elastic layer: add 0.3% of the hydroxylated graphene mass fraction to the matrix material, ultrasonically disperse it to make it fully dispersed, obtain a modified matrix, for use; lay a multi-level layer on the surface of the inner rigid layer The heterogeneous fiber preform is then filled, smeared or sprayed with 4 mm of the above modified matrix, and cured; the above steps are repeated 3 times to obtain the intermediate elastic layer.

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method, put the layered material into the hot pressing mold of the hot pressing furnace for 3-stage vacuuming, after the vacuum degree is extracted, heating at 220 ℃; after the temperature is reached, uniform pressure and pressure hold for 28 min (3MPa); After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.

Comparative Example 1:

To prepare porous metal/hybrid fiber reinforced elastic layer/ceramic layered composite material, the specific preparation method is as follows:

(1) Chopped polyimide fiber, chopped alkali-resistant glass fiber, chopped ultra-high molecular weight polyethylene fiber, chopped silicon carbide fiber, chopped steel fiber, chopped carbon fiber, short The cut alumina fibers and chopped silicon carbide fibers are fully and uniformly dispersed in a modified polyurea matrix with the same formula and thickness as in Example 6 to obtain an intermediate elastic layer.

(2) Using 3D printing technology, prepare a titanium alloy layer with porosity, pore size distribution, and thickness.

(3) According to the thickness ratio between layers in Example 6, the porous titanium alloy/middle elastic layer/alumina ceramics were laminated, and the layers were coated with bisphenol A epoxy resin with silane coupling agent, and vacuum heating was used. Pressure diffusion bonding method, the layered material is put into the hot pressing mold of the hot pressing furnace for 3-level vacuuming. After the vacuum degree is drawn, it is heated at 220 ℃; after the temperature is reached, it is uniformly pressurized and pressure-maintained for 28 min ( 3MPa); After the hot press molding is completed, the temperature is cooled down to obtain a porous metal/hybrid fiber reinforced elastic layer/ceramic layered composite material, and its impact strength is used as the test benchmark.

The composite material samples prepared in Comparative Example 1 and Examples 1-6 were subjected to corresponding impact strength tests.

Fiber mechanical performance test: Use universal testing machine, adopt 5mm/min tensile speed, fiber length is 250mm.

Poisson's ratio test: The digital speckle correlation method is used in conjunction with the test calculation of the universal test machine. The loading speed of the mechanical test machine is 5mm/min.

Composite material impact strength test: According to GB/T1451, use a universal testing machine to test to obtain the composite material's impact strength.

Table 1 The parameters of the fiber of Comparative Example 1 and the fiber preforms prepared in Examples 1-6

纤维预制体Fiber preform	对照实施例1Comparative Example 1	实施例1Example 1	实施例2Example 2	实施例3Example 3	实施例4Example 4	实施例5Example 5	实施例6Example 6
泊松比值Poisson's ratio	0.40.4	-6.25-6.25	-7.58-7.58	-8.86-8.86	-9.45-9.45	-10.68-10.68	-11.39-11.39

Table 2 The impact strength of the anti-explosive and anti-impact composite materials prepared in Comparative Example 1 and Examples 1-6

It can be seen from Table 1 that the Poisson's ratio of the fiber preforms prepared in Examples 1-6 is -6.25 to -11.39, while the Poisson's ratio of the fiber described in the comparative example is 0.4. It can be seen that, compared with the fibers in the prior art, the negative Poisson effect of the multi-stage fiber preform described in this application is more significant; and as the number of auxiliary fibers in the fiber preform increases, the negative Poisson's ratio The effect is gradually increasing.

It can be seen from Table 2 that the impact strength of the composite material prepared in Examples 1-6 is significantly improved compared with that of Comparative Example 1, indicating that its anti-knock and impact resistance has been greatly improved. Compared with the metal/hybrid fiber reinforced elastic layer/ceramic composite material of the same system, the impact resistance of the composite material prepared in this application can be increased by 268.3%, indicating the design of the fiber preform and the inner recessed metal of the composite material. And the gradient combination between multilayer materials has a significant effect of enhancing impact and explosion resistance.

Claims

The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material is composed of at least one layered unit structure of inner surface viscoelastic layer-inner rigid layer-middle elastic layer-outer surface high-strength layer; it is characterized in that: the middle elastic layer includes A matrix material and a multi-stage heterogeneous fiber preform with a negative Poisson's ratio effect arranged in the matrix material; the fiber preform is formed by a flat woven warp and weft of a plurality of multi-stage heterogeneous fibers; the multi-stage heterogeneous fiber It is formed by winding multi-level auxiliary fibers on a core fiber; the core fiber is a low-modulus fiber, and the multi-level auxiliary fiber includes high-modulus fibers with different elastic modulus sequentially wound on the core fiber; The elastic modulus of the primary secondary fiber in the secondary fiber is 50GPa-90GPa; the ratio of the elastic modulus of the Nth secondary fiber to the N-1th secondary fiber is 1.1-9.6, N=2-7; the core fiber The diameter ratio to the first-level auxiliary fiber is 1.5-3.0, the diameter ratio of the core fiber to the N-th auxiliary fiber is 2.5-15.0, and the diameter ratio of the N-th auxiliary fiber to the N-1th auxiliary fiber is 0.5-0.9. N is 2-7; the helix angle of the first-level auxiliary fiber is 2°-8°, the helix angle of the N-th auxiliary fiber is 3°-15° higher than that of the N-1-th auxiliary fiber, and the N-th auxiliary fiber The helix angle is 5°-60°, and N is 2-7.
The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material according to claim 1, wherein the multi-stage heterogeneous fiber preform with negative Poisson's ratio effect in the middle elastic layer is 1 layer to 4 layers The interlayer spacing of the adjacent multi-stage heterogeneous fiber preform is 2mm-20mm; the distance between the core fibers of the adjacent multi-stage heterogeneous fiber is 2mm-50mm; the elastic modulus of the low modulus fiber The elastic modulus of the high-modulus fiber is ≥50GPa; the elastic modulus ratio of the N-th auxiliary fiber to the N-1-th auxiliary fiber is 1.1-7.5, and N is 2-7; The diameter ratio of the core fiber and the first-level auxiliary fiber is 1.5-2.5, the diameter ratio of the core fiber and the N-th auxiliary fiber is 2.5-10.0, the helix angle of the N-th auxiliary fiber is 10°-60°, and N is 2- 7.
The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material according to claim 2, wherein the low modulus fiber is polyethylene fiber, polyvinyl alcohol fiber, polyvinyl formal fiber, polyvinyl chloride One or more of fiber, polypropylene fiber, polyacrylonitrile fiber, polyamide fiber, polyimide fiber, polyester fiber, polyurethane fiber, cellulose fiber, polytetrafluoroethylene fiber and polyphenylene sulfide fiber The high modulus fiber is aramid fiber, polybenzimidazole fiber, polybenzodioxazole fiber, polyarylate fiber, ultra-high molecular weight polyethylene fiber, glass fiber, carbon fiber, steel fiber, continuous basalt fiber, One or more of silicon carbide fibers, magnesia fibers, alumina fibers, silica fibers, quartz fibers, aluminum silicate fibers, graphene fibers, and boron fibers.
The anti-explosion and shock-resistant negative Poisson's ratio gradient composite damping material according to any one of claims 1 to 3, wherein an interface connection layer is provided between two adjacent layers in the gradient composite damping material, The interface connecting layer is one or more of phenolic resin, bisphenol A epoxy resin, silicone resin, alkyd resin, and polyester resin added with a coupling agent.
The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material according to claim 4, characterized in that: the matrix materials of the inner surface viscoelastic layer and the middle elastic layer are epoxy resin and phenolic resin with toughening agent added. One or more of resin, urea-formaldehyde resin, silicone resin, polyurethane and polyurea.
The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material according to claim 4, wherein: the outer high-strength layer is a metal layer with a plurality of inner concave hole structures; the inner concave hole consists of two centers It is composed of a symmetrical six-sided terrace structure, the upper and lower ends of the inner concave hole are the bottom of the regular six-sided terrace, and the tops of the two regular six-sided terraces are connected.
The anti-explosion and shock-resistant negative Poisson's ratio gradient composite damping material according to claim 6, wherein the concave angle α at the top of the two positive six-sided terraces is 120°; the bottom six sides of the positive six-sided terrace The side length of the shape is a, the side length d of the hexagon at the top of the regular six-sided terrace is 0.3a-0.7a, and the height h of the inner concave hole is a-2.4a; the volume of a single inner concave hole It is 100mm 3 -1000mm 3 ; the metal is one or more of aluminum, nickel, magnesium, titanium and their alloys.
The anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material according to claim 4, wherein the internal rigid layer is a ceramic material with an elastic modulus of 220GPa-460GPa, specifically silicon carbide, boron carbide, nitride One or more of silicon, boron nitride, aluminum nitride, alumina and zirconia ceramics.
The method for preparing the anti-explosive and shock-resistant negative Poisson's ratio gradient composite damping material according to claims 1-8, characterized in that: the preparation comprises the following steps:

(1) Preparation of the inner surface viscoelastic layer: adding curing agent and toughening agent to the base material, the mass ratio of curing agent to base material is 1.0:0.8-1.0:1.2, and the amount of toughening agent is the quality of the base material Of 5.0%-10.0% of the content, heated to 50℃-80℃, until the curing is completed to obtain the viscoelastic layer;

(2) Processing and preparation of the internal rigid layer: the surface of the ceramic is processed to improve the roughness, and the laser etching technology is used to irradiate the ceramic with a high-energy laser to melt and re-quench the surface to form scattered small pits, and the roughness is maintained at Ra0 .005-Ra0.015;

(3) Preparation of the middle elastic layer:

(a) Processing and preparation of primary heterogeneous fiber embryo structure: according to the helix angle of the primary structure, the high modulus fiber as the primary auxiliary fiber is wound on the low modulus fiber as the core fiber to prepare Obtain the first-level heterogeneous fiber embryo structure;

(b) Curing treatment of primary heterogeneous fiber embryo structure: add coupling agent, curing agent and toughening agent to the matrix material of the middle elastic layer and stir thoroughly, wherein the amount of coupling agent is 0.1 of the mass of the matrix material %-5.0%, the mass ratio of the curing agent to the matrix material is 1.0:0.8-1.0:1.2, and the amount of the toughening agent is 5.0%-10.0% of the matrix material mass; and then the first stage prepared in step (a) The heterogeneous fiber embryo structure is immersed in it and heated to 50°C-80°C, the first-level heterogeneous fiber embryo structure is fully immersed, and then the curing system is pulled out, and left to stand until the curing is completed, and the first-level heterogeneous fiber structure is obtained;

(c) Processing and preparation of N-level heterogeneous fiber structure: taking the heterogeneous fiber obtained in step (b) as the primary structure, repeating steps (a) and (b) according to the helix angle of the N-level structure to obtain N-grade heterogeneous fiber structure, N is 2-7;

(d) Weaving and preparation of multi-stage heterogeneous fiber preform: the obtained N-stage heterogeneous fiber is woven into a warp-weft plain weave structure according to the warp and weft direction through a warp-weft plain weaving method, and then the solidification system described in step (b) is fully Coat all the warp and weft junctions of the warp and weft plain weave structure, and let it stand until it is cured to obtain an N-grade heterogeneous fiber preform, with N being 2-7;

(e) Preparation of the middle elastic layer: add the hydroxylated graphene with a mass fraction of 0.2%-2.0% to the matrix material, and ultrasonically disperse it to make it fully dispersed to obtain a modified matrix for use; a layer is laid on the surface of the inner rigid layer Layer multi-level heterogeneous fiber preforms, then fill, smear or spray the above modified matrix 2mm-20mm, and solidify; repeat the above steps 0-3 times to obtain the intermediate elastic layer;

(4) Processing and preparation of the external high-strength layer: using selective laser sintering method, using UG software to build a three-dimensional metal model of the inner concave hole, the model is converted into STL format and input into the laser powder sintering rapid prototyping system, and the sintering molding is formed with inner concave holes Structural metal layer;

(5) Lay the inner surface viscoelastic layer-the interface connection layer-the inner rigid layer-the interface connection layer-the middle elastic layer-the interface connection layer-the outer surface high-strength layer in the order from bottom to top, using vacuum hot pressure diffusion bonding Method, put the layered material into the hot pressing mold of the hot pressing furnace for 3-level vacuuming. After the vacuum degree is extracted, heat at 150℃-220℃, and after the temperature reaches, perform uniform pressure and hold the pressure for 20min- 30min; After the hot pressing is completed, the temperature is lowered and the composite damping material with a gradient of anti-explosion and anti-shock negative Poisson's ratio is obtained.
The method for preparing anti-explosion and impact-resistant negative Poisson's ratio gradient composite damping material according to claim 9, wherein the coupling agent is a titanate coupling agent, an aluminate coupling agent, and a bimetallic coupling agent. One or more of the coupling agent and the silane coupling agent; the curing agent is one of polyamide, polyester resin, glycol, polyol, aromatic amine, aliphatic amine curing agent or Multiple; the toughening agent is one or more of carboxyl nitrile rubber, polyvinyl butyral, polyethersulfone, and polyphenylene ether ketone.