Time sequence reaction high-energy insensitive active material, fragment and preparation method

Abstract

The invention discloses a sequential reaction high-energy insensitive active material, a fragment and a preparation method. According to the invention, metal hydride and metal oxide are added on the basis of the existing fluoropolymer-based active material, and a form that metal powder is coated with hydride and fluoropolymer powder is coated with oxide is adopted. The metal powder is coated with the hydride, so that oxidation of the metal powder in the active material fragment preparation and application process is reduced, and the energy content and the reaction capacity of a system are improved; the fluoropolymer powder is coated with the oxide, so that insufficient damage power caused by reaction of the hydride and the fluoropolymer in the early stage of penetration is avoided; meanwhile, after the active fragments penetrate through the target plate, the shell structure is broken, hydride with a low reaction threshold value and fluoropolymer are subjected to primary reaction at first to release energy, then metal powder with high energy release and high reaction threshold value and metal oxide are subjected to secondary reaction under the action of impact load and primary reaction energy, and the metal powder with high energy release and high reaction threshold value and metal oxide are subjected to secondary reaction. The total reaction energy of the system can reach 50%-70% of the theoretical energy content.

Description

Technical Field

[0001] This invention relates to the field of active materials technology, specifically to a time-reaction high-energy insensitive active material, fragments, and preparation method. Background Technology

[0002] Reactive damaging materials refer to a class of metastable energetic materials that self-activate and undergo chemical reactions under impact loads. Due to their ability to both penetrate and explode, they have attracted the attention of researchers in the field of endpoint damage effects. Typical reactive damaging materials are fluoropolymer-based reactive materials, composed of a fluoropolymer matrix, active metals, modified metals, and their compounds, with PTFE / Al being the most common system. In the application of reactive damaging materials, the energy release behavior of the reaction directly affects the endpoint power of the damaging element. In existing schemes, to increase the reaction energy of reactive damaging materials, metal hydrides (such as LiH, MgH2, TiH2, ZrH2, etc.) or metal oxides (such as Fe2O3, V2O5, MnO2, MoO3, etc.) are usually added to the system.

[0003] Although adding metal hydrides or metal oxides can increase the energy release of PTFE / Al active materials by approximately 40%–50%, theoretical energy calculations show that the energy content of the active material system with added metal hydrides or oxides can be up to double that without them. This indicates that the energy release of PTFE / Al / metal hydride or metal oxide active materials is incomplete during the impact response. Using nano-metal powders can improve surface contact and thus increase reaction efficiency, but it also makes the metal powder more susceptible to oxidation, leading to a decrease in energy content and reaction performance. This, to some extent, limits the further application of PTFE / Al / metal hydride or metal oxide active material destructive agents. Summary of the Invention

[0004] In view of this, the present invention provides a time-series reaction high-energy insensitive active material, fragments and preparation method, which can effectively improve the reaction energy of the active material system.

[0005] The time-reaction high-energy insensitive active material of the present invention comprises: a fluoropolymer-based active material, a metal hydride, and a metal oxide; wherein the metal hydride coats the active metal powder in the fluoropolymer-based active material, and the metal oxide coats the fluoropolymer material powder in the fluoropolymer-based active material. The mass ratio of active metal powder in the metal hydride-fluorinated polymer-based active material is 0.10~0.44; The mass ratio of fluorinated polymer powder to metal oxides in fluorinated polymer-based active materials is 0.28~0.46; The mass ratio of metal hydride-coated active metal powder to metal oxide-coated fluoropolymer powder is 0.38~0.85.

[0006] Preferably, the fluoropolymer-based active material is a basic formulation composed of fluoropolymer material powder and active metal powder, or a derivative formulation in which modified metals are added to the basic formulation.

[0007] Preferably, in the fluoropolymer-based active material, the fluoropolymer powder is preferably polytetrafluoroethylene, vinylidene fluoride-trifluorochloroethylene, polyvinylidene fluoride, polyvinylidene fluoride, or ethylene-trifluorochloroethylene, with a particle size preferably of 58-90 μm; the active metal powder is preferably Al, Mg, Ti, Zr, or Hf, with a particle size preferably of 75-106 μm.

[0008] Preferably, the metal hydride is TiH2, TiH, ZrH2, MgH2, or LiH; the particle size of the metal hydride is preferably 13~38μm.

[0009] Preferably, the metal oxide is Fe2O3, Fe3O4, MnO2, NiO, V2O3, or MoO3; the particle size of the metal oxide is preferably 10~25μm.

[0010] This invention provides a method for preparing the above-mentioned material, specifically using the following method to prepare metal hydride-coated active metal powder: Step 1: Add the active metal powder, metal hydride powder, and binder to an organic solvent and mix thoroughly to obtain a mixture; Step 2: The mixture obtained in Step 1 is subjected to ultrasonic treatment to obtain a suspension; Step 3: Add the emulsifier to deionized water and heat and stir to obtain an emulsion; the emulsifier is preferably polyvinyl alcohol, polyethylene glycol, polyacrylic acid, etc. Step 4: Using a high-speed dispersion homogenizer, add the suspension obtained in Step 2 to the emulsion obtained in Step 3, so that the suspension is fully encapsulated in the emulsion to obtain an oil-in-water emulsion. Step 5: The oil-in-water emulsion obtained in Step 4 is subjected to evaporation, filtration, washing, and drying to obtain metal hydride-coated active metal powder.

[0011] Preferably, in step one, the adhesive is preferably a phenolic resin, epoxy resin or polyurethane resin, and the mass of the adhesive preferably accounts for 0.3 to 0.4% of the mass of the mixed powder.

[0012] The present invention also provides a method for preparing the above-mentioned material, specifically comprising the following steps for preparing metal oxide-coated fluoropolymer material powder: Step 6: Thoroughly mix the fluoropolymer powder and the metal oxide powder to obtain a mixed powder; Step 7: Mix the powder obtained in Step 6 with the microcrystalline wax by vibrating thoroughly to obtain a powder mixture; Step 8: Add the powder mixture obtained in Step 7 to an organic solvent for wet ball milling. After ball milling, filter, wash, and dry to obtain metal oxide-coated fluoropolymer material powder.

[0013] The present invention also provides a time-reaction high-energy insensitive active fragment, which is obtained by mixing, molding and sintering materials prepared by the above-mentioned materials or preparation methods.

[0014] Preferably, the sintering process employs vacuum sintering or spark plasma sintering.

[0015] Beneficial effects: (1) The present invention adopts the method of coating active metal powder with hydride, which reduces the oxidation of active metal powder during the preparation and application of active material fragments, and improves the energy content and reactivity of the system; (2) The present invention uses a method of preparing active fragments by mixing hydride-coated active metal powder and metal oxide-coated fluorinated polymer powder, and reasonably controls the reaction sequence between hydride and fluorinated polymer, and between active metal and metal oxide to improve the total energy of the system. On the one hand, the reaction threshold between hydrides and fluorinated polymers is low, and they are prone to premature reaction and energy release during the collision with the target plate, making it impossible to effectively damage the target behind the target. By using a core-shell structure of metal oxides to coat the fluorinated polymers, the hydrides and fluorinated polymers are physically isolated, preventing them from reacting in the early stages of penetration and thus avoiding insufficient damage. On the other hand, when the prepared fragments penetrate the target plate, the hydride and metal oxide shells are subjected to strong impact loads, undergoing intense plastic deformation under pressure, leading to temperature rise and fragmentation. The hydride and fluorinated polymers undergo a primary chemical reaction upon initial contact, releasing energy. Simultaneously, the energy released by the complete reaction of active metals and metal oxides is high, but a high activation threshold is required. The high temperature and high pressure field generated by the reaction of hydrides and fluorinated polymers promotes further secondary reactions between the active metals and metal oxides, releasing energy and increasing the energy release rate of the system. Compared to the traditional method of increasing the energy release of the system by 40% to 50% by simply changing the ratio, this invention can increase the energy release of the reaction system to 50% to 70% through reasonable ratios.

[0016] (3) The preparation process of the present invention is simple and has good stability, which is conducive to the realization of engineering applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the energy release process of the reaction between fluorinated polymers / metals / metal hydrides.

[0018] Figure 2 This is a schematic diagram of the energy release process of the reaction between fluorinated polymers / metals / metal oxides.

[0019] Figure 3 This is a schematic diagram of the structure of the active material of the present invention.

[0020] Figure 4 This is a schematic diagram of the energy release process of the active material fragmentation reaction in this invention.

[0021] Figure 5 These are experimental images of the overpressure test of the fragmentation reaction of the active material of this invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] This invention provides a time-dependent high-energy insensitive active material by adding metal hydrides and metal oxides to existing fluoropolymer-based active materials. The fluoropolymer-based active material can be a basic formulation composed of fluoropolymer material powder and active metal powder, or a derived formulation with modified metals such as Cu and W added to the basic formulation. The metal hydride coats the active metal powder in the fluoropolymer-based active material, and the metal oxide coats the fluoropolymer material powder in the fluoropolymer-based active material. Mixing the coated powders prepares an active material destructive element, which can significantly improve the reaction energy release capability of the fluoropolymer-based active material / metal hydride / metal oxide system.

[0024] Among them, the fluorinated polymer-based active material preferably contains polytetrafluoroethylene, vinylidene fluoride-trifluorochloroethylene, polyvinyl fluoride, polyvinylidene fluoride, olefin-trifluorochloroethylene, etc., with a particle size preferably of 58~90μm; the active metal powder preferably contains Al, Mg, Ti, Zr, Hf, etc., with a particle size preferably of 75~106μm.

[0025] The preferred metal hydrides are materials with strong stability such as TiH2, TiH, ZrH2, MgH2, and LiH, which release energy when reacting with fluorinated polymers. The preferred particle size is 13~38μm. The preferred mass ratio of the metal hydride to the active metal powder in the fluorinated polymer-based active material is 0.10~0.44. The preferred metal oxides are materials such as Fe2O3, Fe3O4, MnO2, NiO, V2O3, and MoO3, which have high energy release and low reaction threshold when reacting with active metals, and the preferred particle size is 10~25μm; the preferred mass ratio of the metal oxide to the fluorinated polymer powder in the fluorinated polymer-based active material is 0.28~0.46.

[0026] This invention employs a method of coating metal powder with hydrides and fluoropolymer powder with metal oxides. On one hand, this reduces the oxidation of metal powder during the preparation and application of the active material (such as fragments), improving the system's energy content and reactivity, and avoiding insufficient destructive power due to the reaction between the fluoropolymer and metal hydride in the early stages of penetration. On the other hand, this core-shell structure allows for more effective adjustment of the reaction sequence between hydrides and fluoropolymers, and between the active metal and metal oxide, increasing the energy released by the system: when the prepared active fragments penetrate the target plate, the hydride... When the metal oxide shell is subjected to strong impact loads, it undergoes intense plastic deformation under pressure, leading to a temperature rise and eventual breakage. Due to the low reaction threshold of hydrides and fluorinated polymers, the hydrides and fluorinated polymers undergo a primary reaction first, releasing energy. The active metal and metal oxide have high activation thresholds, but under the combined influence of impact loads and the high-temperature, high-pressure field generated by the reaction of metal hydrides and fluorinated polymers, a secondary reaction is initiated between the active metal and the metal oxide. The complete reaction of aluminum and metal oxide releases a high amount of energy, effectively improving the energy release rate of the system. The total reaction energy of the system can reach 50-70% of the theoretical energy content.

[0027] The preferred mass ratio of metal hydride-coated metal powder to metal oxide-coated fluoropolymer powder is 0.38–0.85. Insufficient hydride-coated aluminum powder will result in insufficient energy release from the primary reaction, failing to fully induce the secondary reaction and reducing the total energy released by the system. Conversely, excessive hydride-coated aluminum powder will lead to insufficient reaction ratios between the fluoropolymer and hydride, as well as between the metal oxide and aluminum, preventing the remaining aluminum from reacting with the hydride and further reducing the total energy released by the system. Therefore, a mass ratio of 0.38–0.85 for hydride-coated aluminum powder to metal oxide-coated fluoropolymer material is suitable.

[0028] The metal hydride-coated metal powder can be prepared using the following steps: Step 1: Add the metal powder, metal hydride powder, and binder to the acetone solution and mix thoroughly to obtain a mixture; The adhesive is preferably a phenolic resin, epoxy resin, polyurethane resin, etc., and the mass of the adhesive preferably accounts for 30% to 40% of the mass of the metal, metal hydride, and adhesive mixture. Step 2: The mixture obtained in Step 1 is subjected to ultrasonic treatment to obtain a suspension; Step 3: Add the emulsifier to deionized water, heat and stir to obtain an emulsion; The emulsifier is preferably polyvinyl alcohol, polyethylene glycol, or polyacrylic acid; the mass of the emulsifier is preferably 0.45% to 0.55% of the total mass of the emulsion. Step 4: Using a high-speed dispersion homogenizer, add the suspension obtained in Step 2 to the emulsion obtained in Step 3, so that the suspension is fully encapsulated in the emulsion to obtain an oil-in-water emulsion. Step 5: The oil-in-water emulsion obtained in Step 4 is evaporated, filtered, washed, and dried to obtain metal hydride-coated metal powder; The following steps were used to prepare metal oxide-coated fluoropolymer powder: Step 6: Thoroughly mix the fluoropolymer material powder and the metal oxide powder to obtain a mixed powder; Step 7: Mix the powder obtained in Step 6 with the microcrystalline wax by vibrating thoroughly to obtain a powder mixture; The preferred mass ratio of the mixed powder to the microcrystalline wax is 4 to 5.6. Step 8: Add the powder mixture obtained in Step 7 to an organic solvent for wet ball milling. After ball milling, filter, wash, and dry to obtain metal oxide-coated fluoropolymer material powder. The organic solvent is preferably anhydrous ethanol, isopropanol, etc.

[0029] Step 9: Mix the metal hydride-coated metal powder obtained in Step 5 and the metal oxide-coated fluoropolymer powder obtained in Step 8, mold them, and sinter them to obtain a reaction-induced high-energy active material fragment.

[0030] The molding pressure is preferably 100~300MPa, and the holding time is preferably 1~5min.

[0031] The preferred sintering process is vacuum sintering or spark plasma sintering.

[0032] Example 1 A time-reactive, sensitizing active material is made by adding titanium hydride powder and molybdenum oxide powder to an existing PTFE / AL active material; wherein the titanium hydride powder coats PTFE and the molybdenum oxide powder coats aluminum powder.

[0033] The preparation method of this time-response reactive material is as follows: S1. Preparation of titanium hydride-coated aluminum powder: S1.1: Add 5g of aluminum powder, 2g of titanium hydride powder and 3g of phenolic resin to 50ml of acetone solution and mix well; S1.2: The mixture obtained in S1.1 is subjected to ultrasonic treatment to obtain a suspension; S1.3: Add 0.5g of polyvinyl alcohol emulsifier to 50ml of deionized water and heat and stir to obtain an emulsion; S1.4: Using a high-speed dispersion homogenizer, add the suspension obtained in S1.2 to the emulsion obtained in S1.3 to fully encapsulate the suspension in the emulsion and obtain an oil-in-water emulsion; S1.5: The oil-in-water emulsion obtained in S1.4 is subjected to evaporation, filtration, washing and drying to obtain titanium hydride coated aluminum powder; S2. Preparation of MoO3-coated PTFE powder: S21: Mix 7g of PTFE powder and 3g of MoO3 powder thoroughly and evenly; S22: Mix the powder obtained in S21 with 2.5g of microcrystalline wax by vibrating thoroughly to obtain a powder mixture; S23: Add the mixture powder obtained in S22 to anhydrous ethanol for wet ball milling. After ball milling, filter, wash and dry to obtain MoO3-coated PTFE powder. S3: Take 3g of titanium hydride-coated aluminum powder obtained in S1 and 7g of molybdenum oxide-coated polytetrafluoroethylene powder obtained in S2 and mix them thoroughly to obtain a time-sensitive reactive material.

[0034] S4: Take 4g of the mixed powder obtained in S3 and place it in a cylindrical mold to form a shape. Press the mold at a pressure of 200MPa and hold it for 1min. S5: Take the cylinder obtained in S4 and place it in a vacuum sintering furnace for sintering at a temperature of 380℃ and a holding time of 4h to obtain fragments of active material.

[0035] Experiments were conducted on the active material fragments prepared in Example 1. Under the collision conditions of 1200 m / s, the reaction overpressure of the fragments was approximately 2.4 MPa, which is 12.5% ​​higher than that of PTFE / Al / MoO3 (approximately 2.1 MPa) under the same conditions, and 21% higher than that of PTFE / Al / TiH2 (approximately 1.9 MPa) under the same conditions.

[0036] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A time-response high-energy insensitive active material, characterized in that, include: Fluoropolymer-based active materials, metal hydrides, and metal oxides; wherein the metal hydride coats the active metal powder in the fluoropolymer-based active material, and the metal oxide coats the fluoropolymer material powder in the fluoropolymer-based active material. The mass ratio of active metal powder in the metal hydride-fluorinated polymer-based active material is 0.10~0.44; The mass ratio of fluorinated polymer powder to metal oxides in fluorinated polymer-based active materials is 0.28~0.46; The mass ratio of metal hydride-coated active metal powder to metal oxide-coated fluoropolymer powder is 0.38~0.

85.

2. The material as described in claim 1, characterized in that, The fluoropolymer-based active material is a basic formulation composed of fluoropolymer material powder and active metal powder, or a derivative formulation in which modified metals are added to the basic formulation.

3. The material as described in claim 1 or 2, characterized in that, In the fluoropolymer-based active material, the fluoropolymer powder is made of polytetrafluoroethylene, vinylidene fluoride-trifluorochloroethylene, polyvinylidene fluoride, polyvinylidene fluoride, or ethylene-trifluorochloroethylene, with a particle size of 58~90μm; the active metal powder is made of Al, Mg, Ti, Zr, or Hf, with a particle size of 75~106μm.

4. The material as described in claim 1, characterized in that, The metal hydrides are TiH2, TiH, ZrH2, MgH2, and LiH; the particle size of the metal hydrides is 13~38μm.

5. The material as described in claim 1, characterized in that, The metal oxides are Fe2O3, Fe3O4, MnO2, NiO, V2O3, and MoO3; the particle size of the metal oxides is 10~25μm.

6. The method for preparing the material according to any one of claims 1 to 5, characterized in that, Metal hydride-coated active metal powders were prepared using the following method: Step 1: Add the active metal powder, metal hydride powder, and binder to an organic solvent and mix thoroughly to obtain a mixture; Step 2: The mixture obtained in Step 1 is subjected to ultrasonic treatment to obtain a suspension; Step 3: Add the emulsifier to deionized water, heat and stir to obtain an emulsion; Step 4: Using a high-speed dispersion homogenizer, add the suspension obtained in Step 2 to the emulsion obtained in Step 3, so that the suspension is fully encapsulated in the emulsion to obtain an oil-in-water emulsion. Step 5: The oil-in-water emulsion obtained in Step 4 is subjected to evaporation, filtration, washing, and drying to obtain metal hydride-coated active metal powder.

7. The method as described in claim 6, characterized in that, In step one, the adhesive is phenolic resin, epoxy resin or polyurethane resin, and the adhesive accounts for 0.3 to 0.4% of the mass of the mixed powder.

8. The method for preparing the material according to any one of claims 1 to 5, characterized in that, The following steps were used to prepare metal oxide-coated fluoropolymer powder: Step 6: Thoroughly mix the fluoropolymer powder and the metal oxide powder to obtain a mixed powder; Step 7: Mix the powder obtained in Step 6 with the microcrystalline wax by vibrating thoroughly to obtain a powder mixture; Step 8: Add the powder mixture obtained in Step 7 to an organic solvent for wet ball milling. After ball milling, filter, wash, and dry to obtain metal oxide-coated fluoropolymer material powder.

9. A time-response high-energy insensitive active fragment, characterized in that, It is obtained by mixing, molding, and sintering the material or the material prepared as described in any one of claims 1 to 8.

10. The fragment as described in claim 9, characterized in that, The sintering process employs vacuum sintering or spark plasma sintering.

Images