Active damaging materials with both mechanical strength and deflagration properties and their preparation methods

Abstract

This invention discloses an active damaging material possessing both mechanical strength and detonation properties, and its preparation method. The steps are as follows: S1: Mix the active material with a hydrogen storage material; S2: Disperse metal nitrate hydrate and benzene-1,3,5-tricarboxylic acid in a mixed solution and react to obtain a metal-organic framework material; S3: Disperse mixture A in Tris-HCl buffer solution, then add the metal-organic framework material and continue mixing to obtain mixture B; S4: Add a conductive polymer and a catalyst precursor to mixture B and mix evenly to obtain mixture C; S5: Form mixture C into a cylindrical charge using a press, and then microwave-heat the cylindrical charge under vacuum and protective gas conditions to obtain the active damaging material. This invention improves the mechanical and detonation / deflagration properties of the active material, avoids the cumbersome sintering process, and has widely available raw materials, mature production technology, and low price, showing great application prospects.

Description

Technical Field

[0001] This invention relates to the field of explosion technology, and in particular to an active damaging material that combines mechanical strength and deflagration properties, and a method for preparing the same. Background Technology

[0002] Reactive destructive materials are metal-oxidizer systems made from various non-explosive solid substances through specific methods. Under heating or high-speed impact conditions, they can react with air, releasing a large amount of chemical energy. Because they possess both the mechanical strength of traditional inert metal destructive elements and the explosive energy of traditional energetic materials, they are commonly used in weapon design systems such as high-explosive fragmentation warheads, shaped charge warhead liner, and penetrating warhead cores. With the continuous innovation of modern warfare weapons, higher requirements are being placed on the destructive performance of reactive materials. Excellent reactive materials capable of achieving a combined kinetic and explosive energy destructive effect must possess sufficient mechanical strength and inert impact bluntness to effectively penetrate and damage the target while resisting vibrations during transport and meeting the vibration, shock, and overload requirements during weapon launch. Furthermore, upon reaching the activation threshold, they must generate sufficient deflagration / explosion energy to meet the explosive damage requirements of the weapon system. Represented by polytetrafluoroethylene / aluminum (PTFE / Al) reactive damage materials, high-density metals such as tungsten (W) and tantalum (Ta) are typically added as metal fillers to increase the material density and improve its penetration capability. While the addition of tungsten powder can increase the density of the formulation system, the final reaction temperature and gas production decrease significantly with increasing content. When PTFE / Ta is prepared using the same process as PTFE / Al, volatile tantalum fluoride compounds are generated, which easily undergo a strong exothermic reaction, leading to spontaneous combustion of PTFE / Ta during sintering. If thermally conductive "bridges" can be built between particles while improving the mechanical properties and mechanosensitivity of the reactive material, it can not only effectively increase the density of the damage material system and enhance the weapon's kinetic energy penetration capability, but also improve its heat transfer capacity and energy release rate due to the presence of thermally conductive materials between the particles. Therefore, how to effectively coat the material particles and cleverly connect them is an urgent problem to be solved.

[0003] CN107309429B discloses a method for preparing a powder-packed all-metal active material. This method involves multi-pass continuous rolling of the active material obtained by powder pressing to produce an all-metal active material with high energy release characteristics. However, the active components remain in a mechanically packed state, resulting in poor plastic deformation at room temperature and a high susceptibility to cracking during processing. CN113649562A discloses a method for improving the flowability and reactivity of energetic active materials. This method utilizes the low-gap design of the impellers in a dual planetary mixer and the shearing action of the high-speed dispersion disk to ensure thorough dispersion and uniform mixing of solid materials, thereby improving the overall flowability and reactivity of the material. However, the improvement in processing uniformity does not significantly enhance the final damage effect. CN109465459A discloses a novel nickel-aluminum (Ni-Al)-based all-metal energetic material and its preparation method. This method involves adding an appropriate amount of magnesium-aluminum alloy (Al) to the Ni-Al base. 12 Mg 17 Metal components such as Al 12 Mg 17 The powder, acting as a reinforcing phase, is uniformly distributed within the Al matrix, improving the mechanical strength of the active material. Furthermore, as an energetic material, it effectively enhances the chemical energy release characteristics of the system, strengthening its overall resilience. CN1524972A and CN103773983A describe materials prepared using hot pressing and hot isostatic pressing methods, respectively, achieving relative densities as high as 95–99.8%. However, these materials exhibit extremely low porosity, making them difficult to reactivity under impact loads. US2011 / 0223343Al discloses a method for synthesizing carbon nanotubes, using a single material as both a carbon source and catalyst, and generating carbon nanotubes under microwave energy. This method requires simple and inexpensive equipment, is suitable for large-scale production, and has a very broad application prospect. Furthermore, this method can grow a forest of carbon nanotubes on the surface of the composite reinforcement, effectively enhancing the interfacial mechanical properties of the composite material, particularly its resistance to fatigue fracture.

[0004] Therefore, there is a need to develop impact reactive materials with sufficient mechanical strength and guaranteed energy density. These materials should avoid complex and time-consuming production processes while also exhibiting good storage stability and safety during production and transportation. Summary of the Invention

[0005] Based on the technical problems existing in the background technology, this invention proposes an active damaging material with both mechanical strength and deflagration performance and its preparation method. It improves the mechanical and deflagration / detonation properties of the active material, avoids the cumbersome sintering process, and has a wide range of raw material sources, mature production technology, and low price, thus having a good application prospect.

[0006] The active damaging material proposed in this invention, which combines mechanical strength and deflagration performance, comprises the following raw materials in parts by weight: 5-25 parts of hydrogen storage material, 50-85 parts of active material, 4-9 parts of metal-organic framework material, 5-15 parts of conductive polymer, and 10-30 parts of catalyst precursor.

[0007] Preferably, the hydrogen storage material is one or more of titanium hydride, magnesium hydride, zirconium hydride, complex hydrogen storage material powder, and metal borohydride.

[0008] Preferably, the active material is one or more of Al / PTFE, hafnium / tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, and Al / Ni.

[0009] Preferably, the metal-organic framework material is one of Cu-MOF, Co-MOF, and Zn-MOF.

[0010] Preferably, the conductive polymer is one of polyacetylene, polypyrrole, polyaniline, polythiophene, poly(p-phenylenevinylene), poly(p-phenylene), and polydiyne.

[0011] Preferably, the catalyst precursor is one of ferrocene, nickel formate, and cobalt acetate.

[0012] The preparation method of the above-mentioned active damaging material with both mechanical strength and deflagration properties proposed in this invention comprises the following steps:

[0013] S1: Mix the dried active material with the hydrogen storage material to obtain mixture A;

[0014] S2: Metal nitrate hydrate and benzene-1,3,5-tricarboxylic acid are uniformly dispersed in a DMF-ethanol-water mixed solution for reaction. The product is washed and dried to obtain a metal-organic framework material.

[0015] S3: Disperse mixture A in Tris-HCl buffer, then add metal-organic framework material and continue mixing, and finally filter and dry to obtain mixture B;

[0016] S4: Add conductive polymer and catalyst precursor to mixture B and mix evenly to obtain mixture C;

[0017] S5: The mixture C is made into a columnar charge in a press, and then the columnar charge is microwave heated under vacuum and protective gas conditions to obtain the active damage material.

[0018] Preferably, the drying temperature in S1 is 50-70℃, and the drying time is 2-5 hours.

[0019] Preferably, the reaction conditions in S2 are as follows:

[0020] Preferably, the microwave heating power in S5 is 700-1000W, and the time is 5-15s.

[0021] Beneficial technical effects of the present invention:

[0022] 1. The hydrogen gas and matrix metal products generated during the decomposition of the hydrogen storage material powder added in this invention can not only react with the outside world to release a large amount of energy and generate a high-pressure enhanced damage effect, but also help to accelerate the system reaction rate and improve the energy release characteristics of the active material.

[0023] 2. The present invention utilizes an in-situ carbon fiber generation method that can not only improve the mechanical properties of active material components, but also, as an energetic material, carbon fiber can effectively improve the overall weapon system's destructive capability after the material reaches the activation threshold.

[0024] 3. The present invention utilizes an in-situ carbon fiber generation method, which avoids the damage to carbon fibers caused by stirring and mixing during the addition of carbon fiber materials in traditional methods, thus seriously affecting the density and mechanical strength of the prepared material.

[0025] 4. The present invention uses microwaves to form carbon fibers between particles after the material is pressed and molded. Therefore, the degree of bonding between particles is higher than that of traditional materials that add carbon fibers first and then form them. The mixing uniformity is also better, and the mechanical and damage properties are also better.

[0026] 5. This invention utilizes in-situ polymerization technology to prepare core-shell active materials. While ensuring good deflagration / detonation performance, the resulting active materials possess good thermal stability and low mechanical sensitivity, effectively solving problems such as reduced material activity and material loss during long-term storage, as well as flammability and explosiveness during production and transportation. Furthermore, the copper ions contained in the MOF material also have a good promoting effect on the energy release of the explosion system, showing great potential value in improving the performance of civilian explosives and weapon ammunition.

[0027] 6. Microwave-generated carbon fibers in situ can effectively improve the mechanical and detonation / ignition properties of active materials, avoiding cumbersome sintering processes. Furthermore, the raw materials are widely available, the production technology is mature, and the price is low, thus demonstrating excellent application prospects. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the active material component before microwave treatment proposed in this invention;

[0029] Figure 2 This is a schematic diagram of the structure of the microwave-treated press-fit material proposed in this invention.

[0030] In the figure: 1-Active filler particles, 2-Hydrogen storage material particles, 3-Active substrate particles, 4-Metal-organic framework material, 5-Conductive polymer powder, 6-Ferrocene, 7-In-situ grown carbon fiber. Detailed Implementation

[0031] The present invention will be further explained below with reference to specific embodiments.

[0032] Example 1

[0033] The present invention proposes an in-situ generated carbon fiber TiH2 / Al / PTFE active material: the mass ratio of TiH2 in this carbon fiber active material is 15%, the mass ratio of Al is 15%, the mass ratio of PTFE is 46%, the mass ratio of Cu-MOF is 7%, the mass ratio of conductive polymer polypyrrole is 8%, and the mass ratio of ferrocene is 9%.

[0034] The preparation method of in-situ generated carbon fiber TiH2 / Al / PTFE active material is as follows:

[0035] Step 1: Spread the dried PTFE powder evenly in a shallow container and place it in a vacuum drying oven for 4 hours at a temperature controlled at 60℃. After crushing and sieving, pour the PTFE powder and Al powder into a mixer at a mass ratio of 74:26 and mix for 10 minutes. Then add TiH2 powder and set a mixing time of 30 minutes to achieve uniform mixing of the multi-component powders, thus obtaining a uniformly mixed TiH2 / Al / PTFE powder.

[0036] St2: Place a 40 mL mixture of DMF, ethanol, and water (volume ratio 2:1:1) in a flask, and add a certain amount of Cu(NO3). 2` 3H₂O and H₃BTC were uniformly dispersed in the mixed solution. The prepared solution was then transferred to an oil bath at 90°C, stirred for 8 hours, and cooled to room temperature. It was then washed with DMF and dried at 60°C to obtain a blue Cu-MOF powder.

[0037] St3: A certain mass of the mixed active material powder was placed in a prepared Tris-HCl buffer solution with pH=8.5 and stirred for 30 min (500 rpm). Then, an appropriate amount of Cu-MOF was added, and stirring was continued for 3 h. Finally, the mixture was filtered and dried in an oven for 12 h to obtain TiH2 / Al / PTFE@Cu-MOF powder.

[0038] St4: Add polypyrrole and ferrocene powder to the coated active material powder obtained in St3 according to the component ratio, stir slowly for 20 minutes to make it evenly mixed, and finally obtain a mixture of coated TiH2 / Al / PTFE, polypyrrole and ferrocene.

[0039] St5: The mixture of the three prepared from St4 is placed into a press to form a cylindrical press-filled drug.

[0040] St6: The cylindrical compression charge obtained in St5 is placed in a microwave heater and evacuated. Nitrogen gas is introduced as a protective gas. The machine power is controlled at 900w and the time is controlled at 12s. Finally, TiH2 / Al / PTFE active material with in-situ carbon fiber is obtained.

[0041] Example 2

[0042] The present invention proposes an in-situ generated carbon fiber MgH2 / Hf / THV active material: the mass ratio of MgH2 in this carbon fiber active material is 20%, the mass ratio of Hf is 28%, the mass ratio of THV is 32%, the mass ratio of Co-MOF is 8%, the mass ratio of polyaniline is 4%, and the mass ratio of ferrocene is 8%.

[0043] The preparation method of in-situ generated carbon fiber MgH2 / Hf / THV active material is as follows:

[0044] St1: Add ethyl acetate and THV220 to a vacuum stirred emulsification reactor, controlling the concentration at about 0.1 g / ml. Heat the mixture in a water bath to 72°C, then add Hf powder and continue stirring for 40 min to ensure uniform mixing. Raise the water bath temperature to 82°C, slightly higher than the boiling point of ethyl acetate solvent, and remove the ethyl acetate by distillation. Finally, place the mixture in a vacuum drying oven and vacuum dry for 12 h to obtain the treated Hf / THV active material. Then, place the material in a mixer and mix it with MgH2 powder to obtain MgH2 / Hf / THV mixed powder.

[0045] St2: Following the same method, a certain mass of MgH2 / Hf / THV mixed powder was placed into the prepared Tris-HCl buffer solution and stirred for 40 min (400 rpm). Then, an appropriate amount of Co-MOF was added, and stirring was continued for 3 h. Finally, the mixture was filtered and dried in an oven for 12 h to obtain MgH2 / Hf / THV@Co-MOF powder.

[0046] St3: Add silicon carbide and ferrocene powder to the coated mixed active material powder obtained in St2 according to the component ratio, stir slowly for 20 minutes to make it uniformly mixed, and finally obtain a mixture of coated MgH2 / Hf / THV, silicon carbide and ferrocene.

[0047] St4: The mixture of the three prepared from St3 is placed into a press to form a cylindrical press-filled drug.

[0048] St5: The cylindrical compression charge obtained in St4 is placed in a microwave heater and evacuated. Nitrogen gas is introduced as a protective gas. The machine power is controlled at 1000w and the time is controlled at 15s. Finally, MgH2 / Hf / THV active material with in-situ carbon fiber is obtained.

[0049] Example 3

[0050] The present invention proposes an in-situ generated ZrH2 / Al / Ni active material for carbon fibers: the mass ratio of ZrH2 in this active material is 15%, the mass ratio of Al is 50%, the mass ratio of Ni is 15%, the mass ratio of Zn-MOF is 7%, the mass ratio of conductive polymer polypyrrole is 5%, and the mass ratio of ferrocene is 8%.

[0051] The preparation method of in-situ generated carbon fiber ZrH2 / Al / Ni active material is as follows:

[0052] Step 1: Spread the dried Al powder evenly in a shallow container, place it in a vacuum drying oven, and dry it under vacuum at 70℃ for 3 hours. Then, pour ZrH2, Al powder, and Ni powder into a mixer according to the mass ratio, and set the mixing time to 60 minutes to achieve uniform mixing between the multi-component powders, thus obtaining a uniformly mixed Al / Ni powder.

[0053] St2: Place the ZrH2 / Al / Ni mixed powder into the prepared buffer solution and stir for 30 min (500 rpm). Then add an appropriate amount of Zn-MOF and continue stirring for 3 h. Finally, filter and dry in an oven for 12 h to obtain ZrH2 / Al / Ni@Zn-MOF powder.

[0054] St3: Add polypyrrole and ferrocene powder to the coated active material powder obtained in St2 according to the component ratio, stir slowly for 30 minutes to make it uniformly mixed, and finally obtain a mixture of coated ZrH2 / Al / Ni, polypyrrole and ferrocene.

[0055] St4: The mixture of the three prepared from St3 is placed into a press to form a cylindrical press-filled drug.

[0056] St5: The cylindrical compression charge obtained in St4 is placed in a microwave heater and evacuated. Nitrogen gas is introduced as a protective gas. The machine power is controlled at 1000w and the time is controlled at 15s. Finally, ZrH2 / Al / Ni active material with in-situ carbon fiber is obtained.

[0057] Example 4

[0058] Detonation energy release characteristics and mechanical property tests: To verify the energy release characteristics, enhanced activity damage effect, and mechanical strength of the novel reactive destructive material, detonation loading tests and mechanical property tests were conducted on the sample from Example 1. In the explosion experiment, the distance between the material-encased explosive sample and the sensor was 100 cm, and the measured air-to-air explosion parameters are shown in Table 1.

[0059] Table 1 Results of the explosive loading energy release experiment

[0060]

[0061] As can be seen from Table 1, compared with the traditional metal-fluorine polymer active binary material, the new active ternary material can improve the maximum temperature, peak pressure of shock wave, positive pressure duration and positive impulse of military explosives in the air: the maximum temperature of RDX wrapped with the new active material increases to 1.15 times that of pure binary material RDX, the peak pressure increases to 1.37 times, and the positive impulse increases to 1.41 times.

[0062] At strain rates of 2500–4000 s -1 Within the specified range, both reactive material components exhibited elastoplastic mechanical behavior. The breaking strength of Al / PTFE was 32 MPa, while the in-situ generated carbon fiber significantly improved the breaking strength of the reactive material, reaching 69.5 MPa. The failure strain increased from 0.16 to 0.31. This demonstrates that the novel ternary hybrid reactive destructive material of this application is an impact-response material possessing both excellent detonation performance and mechanical strength.

Claims

1. An active damaging material possessing both mechanical strength and explosive properties, characterized in that, It contains the following raw materials in parts by weight: 5-25 parts hydrogen storage material, 50-85 parts active material, 4-9 parts metal-organic framework material, 5-15 parts conductive polymer, and 10-30 parts catalyst precursor. A method for preparing an active damaging material that combines mechanical strength and deflagration properties, the steps of which are as follows: S1: Mix the dried active material with the hydrogen storage material to obtain mixture A; S2: Metal nitrate hydrate and benzene-1,3,5-tricarboxylic acid are uniformly dispersed in a DMF-ethanol-water mixed solution for reaction. The product is washed and dried to obtain a metal-organic framework material. S3: Disperse mixture A in Tris-HCl buffer solution at pH 8.5, then add metal-organic framework material and continue mixing. Finally, filter and dry to obtain mixture B. S4: Add conductive polymer and catalyst precursor to mixture B and mix evenly to obtain mixture C; S5: The mixture C is made into a columnar charge in a press, and then the columnar charge is microwave heated under vacuum and protective gas conditions to obtain the active damage material. The microwave heating power in S5 is 700-1000w, and the time is 5-15s; The hydrogen storage material is one or more of titanium hydride, magnesium hydride, zirconium hydride, and metal borohydride. The active material is one or more of Al / PTFE, hafnium / tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, and Al / Ni.

2. The reactive damaging material possessing both mechanical strength and explosive properties according to claim 1, characterized in that, The metal-organic framework material is one of Cu-MOF, Co-MOF, and Zn-MOF.

3. The reactive damaging material possessing both mechanical strength and explosive properties according to claim 1, characterized in that, The conductive polymer is one of polyacetylene, polypyrrole, polyaniline, polythiophene, poly(p-phenylenevinylene), poly(p-phenylene), and polydiyne.

4. The reactive damaging material possessing both mechanical strength and explosive properties according to claim 1, characterized in that, The catalyst precursor is one of ferrocene, nickel formate, and cobalt acetate.

5. The reactive damaging material possessing both mechanical strength and explosive properties according to claim 1, characterized in that, The drying temperature in S1 is 50-70℃, and the time is 2-5 hours.

6. The reactive damaging material possessing both mechanical strength and explosive properties according to claim 1, characterized in that, The reaction oil bath in S2 is heated to a temperature of 80-100℃, and the stirring reaction time is 6-8 hours.

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