Pyrotechnic composition as well as preparation method and application thereof
By using nano-manganese difluoride as an energetic additive, the problems of low reaction rate and high cost of traditional pyrotechnic agents have been solved, realizing the preparation of high-performance and low-cost pyrotechnic agents and improving reaction rate and energy output.
Patent Information
- Application Number
- CN202410748423.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-11
- Publication Date
- 2025-12-12
AI Technical Summary
Traditional pyrotechnic agents suffer from low reaction rates, insufficient energy output, and incomplete reactions. Furthermore, existing fluorinated combustion improvers are expensive and unsuitable for large-scale industrial applications.
Nano-manganese difluoride was used as an energetic additive. Ammonium fluoromanganate precursor was prepared by co-precipitation and then pyrolyzed at high temperature to obtain nano-manganese difluoride. Pyrotechnic agents were prepared by combining it with aluminum powder and oxidant. After ultrasonic dispersion and drying, high-performance pyrotechnic agents were obtained.
It significantly improves the reaction rate and energy output of pyrotechnic agents, reduces raw material costs, and achieves the preparation of high-performance and low-cost pyrotechnic agents.
Smart Images
Figure CN121107928A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the formula of the pyrotechnic smoke powder, and particularly relates to a pyrotechnic smoke powder, a preparation method and application thereof, and belongs to the technical field of energetic materials. BACKGROUND
[0002] The pyrotechnic smoke powder is a kind of energetic material which produces special effects such as light, sound, smoke and heat when burning, and is widely used in military and civilian fields. The traditional pyrotechnic smoke powder is usually a mixture of high-energy metal fuel and solid oxidizer. Among them, aluminum powder is widely used in the formula of pyrotechnic smoke powder and explosive due to its high energy density, naturally formed passivation layer and low raw material cost, and is considered to be the best metal fuel in terms of comprehensive performance. However, when the traditional oxygen-based oxidizer reacts with the metal fuel, the oxide passivation layer on the surface of the particle will thicken with the reaction. The oxide generated on the interface will hinder the mass transfer between the fuel and the oxidizer, which will lead to a decrease in reaction rate or incomplete reaction with residues, which is manifested as low energy output or low reaction efficiency in macroscopic view.
[0003] In order to further improve the reaction performance of the pyrotechnic smoke powder, the main direction of current research is to develop new energetic additives. Among them, fluorine-containing combustion improvers represented by high molecular fluoropolymers and organic small molecule fluorides show excellent performance. Since fluorine-containing combustion improvers generate aluminum fluoride or aluminum oxyfluoride when reacting with aluminum powder, its volatility is much higher than that of aluminum oxide, so it can significantly reduce the energy barrier of the reaction interface. However, these organic fluorine compounds usually have high raw material cost and processing cost, and are not suitable for large-scale promotion in industrial applications. In view of the above problems, it is necessary to develop high-performance and low-cost energetic additives for pyrotechnic smoke powder.
[0004] Therefore, it has become a technical problem to be solved in the field to provide a new type of pyrotechnic smoke powder using nanometer manganese difluoride as an energetic additive, and a preparation method and application thereof. SUMMARY
[0005] In order to solve the above-mentioned shortcomings and deficiencies, one object of the present application is to provide a pyrotechnic smoke powder. The pyrotechnic smoke powder provided by the present application is a new type of pyrotechnic smoke powder with high performance and low cost, which solves the problems of low heat release, low gas production and incomplete reaction of the conventional pyrotechnic smoke powder currently used.
[0006] Another object of the present application is also to provide a preparation method of the above-mentioned pyrotechnic smoke powder.
[0007] Still another object of the present application is also to provide the application of the above-mentioned pyrotechnic smoke powder in weapon equipment, aerospace, rescue equipment in blasting industry or gas propulsion.
[0008] To achieve the above object, in one aspect, the present application provides a pyrotechnic composition, wherein, based on the total weight of the pyrotechnic composition, the pyrotechnic composition comprises 20%-50% of fuel, 40%-70% of oxidizer and 3%-10% of energetic additive;
[0009] The energetic additive is nano manganese difluoride, which is in the form of particles with an average diameter less than 300 nm. The exothermic reaction activity of the nano manganese difluoride sample used in the present application is much higher than that of conventional samples, such as non-nano particles or particles with an average diameter not less than 300 nm.
[0010] As a specific embodiment of the pyrotechnic composition described above, the fuel comprises one or a combination of several of metal fuels such as aluminum powder, magnesium powder and boron powder.
[0011] As a specific embodiment of the pyrotechnic composition described above, the oxidizer is a solid oxidizer, which comprises one or a combination of several of solid oxidizers such as perchlorate, nitrate and metal oxide. The perchlorate, nitrate and metal oxide used in the present application are all conventional substances, which can be reasonably selected according to the actual needs of the site operation. For example, in some embodiments of the present application, the perchlorate can be sodium perchlorate (NaClO4), and the metal oxide can be diiron trioxide (Fe2O3).
[0012] In another aspect, the present application also provides a preparation method of the pyrotechnic composition described above, wherein the preparation method comprises:
[0013] adding the fuel, the oxidizer and the nano manganese difluoride energetic additive into an organic solvent to uniformly ultrasonically disperse to obtain a mixed solution, and then drying the mixed solution to remove the organic solvent to obtain the pyrotechnic composition.
[0014] As a specific embodiment of the preparation method described above, the preparation method of the nano manganese difluoride comprises:
[0015] Step (1): mixing an alcohol solution of divalent manganese salt with an aqueous solution of ammonium hydrogen fluoride, and then separating, washing and drying the generated precipitate to obtain an ammonium fluoromanganate precursor;
[0016] Step (2): heating the ammonium fluoromanganate precursor to 350-450℃ under an inert gas environment and maintaining the temperature to obtain nano manganese difluoride.
[0017] The present application first prepares an ammonium fluoromanganate precursor by co-precipitation, then prepares nano manganese difluoride by high-temperature pyrolysis, and then mixes the fuel, the oxidizer and the nano manganese difluoride energetic additive by ultrasonic dispersion, and finally dries to remove the organic solvent to obtain the pyrotechnic composition.
[0018] As a specific embodiment of the above preparation method of the present application, in step (1), the divalent manganese salt includes manganese nitrate and / or manganese bromide, etc.
[0019] As a specific embodiment of the above preparation method of the present application, in step (1), the alcohol solvent used in the alcohol solution includes methanol and / or ethanol, etc.
[0020] As a specific embodiment of the above preparation method of the present application, in step (1), the molar ratio of ammonium bifluoride to divalent manganese salt is 2-4:1.
[0021] As a specific embodiment of the above preparation method of the present application, in step (1), the concentration of the alcohol solution of divalent manganese salt is 0.1-0.3 mol / L, and the concentration of the aqueous solution of ammonium bifluoride is 2-4 mol / L.
[0022] The present application does not make specific requirements for the specific operation and temperature of drying in step (1) of the above preparation method of nanometer manganese difluoride, and can be reasonably adjusted according to the actual needs of the site operation, as long as the purpose of drying can be achieved.
[0023] As a specific embodiment of the above preparation method of the present application, in step (2), the inert gas environment includes nitrogen or argon, etc.
[0024] The present application does not make specific requirements for the holding time in step (2) of the above preparation method of nanometer manganese difluoride, and can be reasonably adjusted according to the actual needs of the site operation, as long as nanometer manganese difluoride can be prepared. For example, in some embodiments of the present application, the holding time can be 1 h.
[0025] As a specific embodiment of the above preparation method of the present application, the organic solvent includes ethanol, isopropanol, acetonitrile or cyclohexane, etc.
[0026] As a specific embodiment of the above preparation method of the present application, the purpose of ultrasonic dispersion is to uniformly disperse each component in the organic solvent, and the ultrasonic dispersion time is more than 1 h, preferably 1-2 h.
[0027] As a specific embodiment of the above preparation method of the present application, the method for removing the organic solvent should be able to maintain the uniform mixing of each component, for example, the organic solvent can be removed by drying method, and the drying is vacuum drying or freeze drying, etc.
[0028] In another aspect, the application also provides application of the above-mentioned pyrotechnic composition in the fields of civil, aerospace and military, such as weapon equipment, ammunition system, aerospace, rescue equipment in blasting industry, automobile or gas propelling. Specifically, the pyrotechnic composition can be used as a primer or propellant and applied in the fields of weapon equipment and ammunition system; the high-pressure products generated by combustion of the pyrotechnic composition can be used for work output, and the pyrotechnic composition can be applied in micro-propelling devices and attitude adjustment devices of micro air vehicles; the pyrotechnic composition can also be used as a gas source of a gas generator and applied in the fields of automobile safety airbags and automatic inflation protection devices.
[0029] Compared with the prior art, the application has the following beneficial technical effects:
[0030] The pyrotechnic composition provided by the application uses nanoscale manganese difluoride as an energetic additive, and the reaction rate, energy output and gas production of the pyrotechnic composition are significantly higher than those of traditional fluorine-free pyrotechnic compositions, which can solve the problems of low heat release, low gas production and incomplete reaction of some current pyrotechnic compositions. Compared with other pyrotechnic compositions using fluoropolymers or small-molecule organic fluorides as energetic additives, the pyrotechnic composition has low raw material cost and processing cost and simple preparation method. In summary, the pyrotechnic composition provided by the application is a new type of pyrotechnic composition with high performance and low cost. BRIEF DESCRIPTION OF DRAWINGS
[0031] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0032] Figure 1 A scanning electron microscope (SEM) image of the n-MnF2 sample prepared in Example 1 of the application.
[0033] Figure 2 An X-ray diffraction pattern of the n-MnF2 sample prepared in Example 1 of the application.
[0034] Figures 3a-3c The pressure output curves of the pyrotechnic composition samples provided by Example 1, Comparative Example 1-1 and Comparative Example 1-2 of the application in a closed cabin are shown in the following figures.
[0035] Figures 4a-4c The pressure output curves of the pyrotechnic composition samples provided by Example 2, Comparative Example 2-1 and Comparative Example 2-2 of the application in a closed cabin are shown in the following figures. DETAILED DESCRIPTION
[0036] It has to be understood that the terms "comprising", "including", "containing", "characterized by" and any other variation thereof in the specification and in the claims are not to be construed as excluding any feature, step or element, but are meant to encompass the possibility of non-exclusive inclusion. Thus, the methods and compositions described herein can include, consist essentially of, or consist of, any element or combination of elements described herein, in any order or arrangement.
[0037] The ranges disclosed herein are given in their absolute form. They can be one or more lower limits, and one or more upper limits. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of a particular range. All ranges defined in this manner are combinable, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if a minimum range value of 1 and 2 is listed, and a maximum range value of 3, 4 and 5 is listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.
[0038] In the present application, unless otherwise stated, the numerical range "a-b" indicates a shorthand for the inclusion of any and all integers between the number "a" and "b", wherein "a" and "b" are real numbers. For example, the numerical range "0-5" indicates that all integers between "0" and "5" have been listed in the present application, and "0-5" is merely a shorthand for the inclusion of these numerical combinations.
[0039] In the present application, unless otherwise stated, all embodiments mentioned in the present application and preferred embodiments can be combined with each other to form new technical solutions.
[0040] In the present application, unless otherwise stated, all technical features mentioned in the present application and preferred features can be combined with each other to form new technical solutions.
[0041] In the present application, unless otherwise stated, all steps mentioned herein can be performed in sequence or randomly, but preferably in sequence. For example, the method comprises steps (a) and (b) indicates that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method further comprises step (c) indicates that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.
[0042] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and examples. The examples described below are part of the examples of the present application, but not all the examples, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.
[0043] Example 1
[0044] The present example provides a pyrotechnic composition using nanometer manganese difluoride as an energetic additive, which is prepared by a preparation method comprising the following specific steps:
[0045] Preparation of nanometer manganese difluoride:
[0046] Step (1): 2.51 g of manganese nitrate tetrahydrate was weighed and dissolved in 40 mL of ethanol, then 10 mL of 4 mol / L ammonium hydrogen fluoride aqueous solution was added dropwise to the obtained solution, and stirring was maintained for 30 minutes, then the precipitate obtained by the reaction was separated by filtration, washed with deionized water and ethanol, and then dried by heating to obtain an ammonium fluoromanganate precursor;
[0047] Step (2): The ammonium fluoromanganate precursor was heated to 400℃ under nitrogen for 1 h, and after cooling, a nanometer manganese difluoride (n-MnF2) sample was obtained;
[0048] The micro-morphology of n-MnF2 is shown in Figure 1 As can be seen from Figure 1 , the prepared n-MnF2 is a particle with a diameter of about 100-150 nm; the crystal structure of the n-MnF2 sample was analyzed using a Bruker D2 Phaser X-ray diffractometer, and the obtained X-ray diffraction spectrum is shown in Figure 2 , which is completely consistent with the standard card spectrum of manganese difluoride (PDF #24-0727) and has no other impurity peaks, indicating that the n-MnF2 sample prepared in the present example has high purity.
[0049] Preparation of pyrotechnic composition:
[0050] Step (3): 150 mg of aluminum powder (Al), 225 mg of sodium perchlorate (NaClO4) and 25 mg of n-MnF2 were weighed and added into 30 mL of isopropyl alcohol, and ultrasonic dispersion was performed for 1 h. Then the obtained suspension was poured into a round bottom flask and the solvent was removed by using the method of reduced pressure distillation, and finally the excess solvent was removed by drying in a vacuum oven at 70 °C for 4 h to obtain a pyrotechnic composition with n-MnF2 as an energetic additive, denoted as Al / NaClO4 / n-MnF2, which contained 37.5% of fuel (aluminum powder), 56.25% of oxidizer (NaClO4) and 6.25% of energetic additive (n-MnF2, which was a particle with a diameter of about 100-150 nm), based on the total weight of the pyrotechnic composition being 100%.
[0051] Example 2
[0052] The present example provides a pyrotechnic composition with n-MnF2 as an energetic additive, which is prepared by using a preparation method comprising the following specific steps:
[0053] Preparation of n-MnF2:
[0054] Step (1): 2.51 g of manganese nitrate tetrahydrate was dissolved in 80 mL of ethanol, and then 20 mL of an aqueous solution of ammonium hydrogen fluoride with a molar concentration of 2 mol / L was added dropwise to the obtained solution while stirring for 30 min. Subsequently, the precipitate obtained by the reaction was separated by filtration, washed with deionized water and ethanol, and then dried by heating to obtain an ammonium fluoromanganate precursor.
[0055] Step (2): The ammonium fluoromanganate precursor was heated to 400 °C under nitrogen for 1 h, and after cooling, a n-MnF2 sample was obtained.
[0056] Preparation of a pyrotechnic composition:
[0057] Step (3): 110 mg of aluminum powder, 265 mg of iron sesquioxide (Fe2O3) and 25 mg of n-MnF2 were weighed and added into 30 mL of isopropyl alcohol, and ultrasonic dispersion was performed for 1 h. Then the obtained suspension was poured into a round bottom flask and the solvent was removed by using the method of reduced pressure distillation, and finally the excess solvent was removed by drying in a vacuum oven at 70 °C for 4 h to obtain a pyrotechnic composition with n-MnF2 as an energetic additive, denoted as Al / Fe2O3 / n-MnF2, which contained 27.5% of fuel (aluminum powder), 66.25% of oxidizer (Fe2O3) and 6.25% of energetic additive (n-MnF2), based on the total weight of the pyrotechnic composition being 100%.
[0058] Comparative Example 1-1
[0059] The comparative example provides a pyrotechnic composition without energetic additive, which is prepared by a preparation method comprising the following specific steps:
[0060] Take 150 mg of aluminum powder (Al) and 225 mg of sodium perchlorate (NaClO4), add them to 30 mL of isopropyl alcohol, and ultrasonically disperse for 1 h; then pour the obtained suspension into a round-bottom flask and remove the solvent by using reduced pressure distillation, and finally dry in a vacuum oven at 70°C for 4 h to remove excess solvent, to obtain a pyrotechnic composition without energetic additive, denoted as Al / NaClO4, which contains 40% fuel (aluminum powder) and 60% oxidizer (NaClO4), based on the total weight of the pyrotechnic composition.
[0061] Comparative example 1-2
[0062] The comparative example provides a pyrotechnic composition with conventional manganese fluoride as an energetic additive, which is prepared by a preparation method comprising the following specific steps:
[0063] Take 150 mg of aluminum powder (Al), 225 mg of sodium perchlorate (NaClO4), and 25 mg of conventional manganese fluoride (Shanghai Aladdin Reagent, manganese (II) fluoride, 98%, particle size about 5-20 μm), add them to 30 mL of isopropyl alcohol, and ultrasonically disperse for 1 h; then pour the obtained suspension into a round-bottom flask and remove the solvent by using reduced pressure distillation, and finally dry in a vacuum oven at 70°C for 4 h to remove excess solvent, to obtain a pyrotechnic composition with conventional manganese fluoride as an energetic additive, denoted as Al / NaClO4 / c-MnF2, which contains 37.5% fuel (aluminum powder), 56.25% oxidizer (NaClO4), and 6.25% energetic additive (c-MnF2), based on the total weight of the pyrotechnic composition.
[0064] Comparative example 2-1
[0065] The comparative example provides a pyrotechnic composition without energetic additive, which is prepared by a preparation method comprising the following specific steps:
[0066] Take 110 mg of aluminum powder and 265 mg of iron sesquioxide (Fe2O3), add them to 30 mL of isopropyl alcohol, and ultrasonically disperse for 1 h; then pour the obtained suspension into a round-bottom flask and remove the solvent by using reduced pressure distillation, and finally dry in a vacuum oven at 70°C for 4 h to remove excess solvent, to obtain a pyrotechnic composition without energetic additive, denoted as Al / Fe2O3, which contains 29.3% fuel (aluminum powder) and 70.7% oxidizer (Fe2O3), based on the total weight of the pyrotechnic composition.
[0067] Comparative example 2-2
[0068] The present comparative example provides a pyrotechnic composition with conventional fluorinated manganese as energetic additive, which is prepared by a preparation method comprising the following specific steps:
[0069] 110 mg of aluminum powder, 265 mg of iron trioxide (Fe2O3) and 25 mg of conventional fluorinated manganese (Shanghai Aladdin Reagent, manganese (II) fluoride, 98%, particle size about 5-20 pm) were weighed and added into 30 mL of isopropyl alcohol, and ultrasonic dispersion was performed for 1 h; then the obtained suspension was poured into a round-bottom flask, and the solvent was removed by vacuum distillation; finally, the excess solvent was removed by drying in a vacuum oven at 70 °C for 4 h, to obtain a pyrotechnic composition with conventional fluorinated manganese as energetic additive, denoted as Al / Fe2O3 / c-MnF2, which contains 27.5% of fuel (aluminum powder), 66.25% of oxidizer (Fe2O3) and 6.25% of energetic additive (c-MnF2), based on the total weight of the pyrotechnic composition.
[0070] Performance test example 1
[0071] The Al / NaClO4 / n-MnF2 provided in Example 1, the Al / NaClO4 provided in Comparative Example 1-1 and the Al / NaClO4 / c-MnF2 provided in Comparative Example 1-2 were subjected to closed ignition test, respectively, including:
[0072] 30 mg of Al / NaClO4 / n-MnF2, Al / NaClO4 and Al / NaClO4 / c-MnF2 were weighed and placed in a stainless steel pressure chamber, respectively, and the Al / NaClO4 / n-MnF2, Al / NaClO4 and Al / NaClO4 / c-MnF2 were subjected to closed ignition test by using nickel-chromium wire heating under constant current condition, and the PCB Piezotronics 112B05 piezoelectric pressure sensor was used to record the pressure generated in the closed chamber, and the test results are shown in Table 1, respectively. Figures 3a-3c Figures 3a-3c The test results shown show that the peak pressure of the Al / NaC104 / n-MnF2 pyrotechnic agent test sample in the embodiment 1 of the present application is 1.67 MPa, and the pressure rise rate is 103 MPa / s; while the peak pressure of the Al / NaC104 blank sample without adding any energetic additive in the comparative example 1-1 is only 1.21 MPa, and the pressure rise rate is only 72 MPa / s, which shows that the addition of the nano manganese difluoride as the energetic additive can effectively improve the pressure output performance of the pyrotechnic agent. In addition, the peak pressure of the Al / NaC104 / c-MnF2 pyrotechnic agent control sample in the comparative example 1-2 adding the conventional manganese difluoride as the energetic additive is only 1.26 MPa, and the pressure rise rate is 98 MPa / s, which is higher than that of the Al / NaC104 blank sample, but still significantly lower than that of the Al / NaC104 / n-MnF2 pyrotechnic agent test sample, which shows that the nano manganese difluoride used in the embodiment of the present application has a much higher performance improvement effect on the pyrotechnic agent than the conventional manganese difluoride.
[0073] Performance test example 2
[0074] The Al / Fe203 / n-MnF2 provided in the embodiment 2, the Al / Fe203 provided in the comparative example 2-1 and the Al / Fe203 / c-MnF2 provided in the comparative example 2-2 are subjected to the closed ignition experiment, including:
[0075] 30 mg of the Al / Fe203 / n-MnF2, the Al / Fe203 and the Al / Fe203 / c-MnF2 are weighed and placed in the stainless steel pressure chamber, the Al / Fe203 / n-MnF2, the Al / Fe203 and the Al / Fe203 / c-MnF2 are subjected to the closed ignition experiment under the condition of constant current heating of the nickel-chromium wire, and the PCB Piezotronics 112B05 piezoelectric pressure sensor is used to record the pressure generated in the closed chamber, and the test results are shown in Figures 4a-4c Figures 4a-4c The test results shown show that the peak pressure of the Al / Fe2O3 / n-MnF2 pyrotechnic agent test sample in the embodiment 2 of the present application is 1.04 MPa, and the pressure rise rate is 95 MPa / s; the peak pressure of the Al / Fe2O3 pyrotechnic agent blank sample without adding any energetic additive in the comparative example 2-1 is only 0.77 MPa, and the pressure rise rate is only 55 MPa / s, which shows that the addition of the nano manganese difluoride as the energetic additive can effectively improve the pressure output performance of the pyrotechnic agent; in addition, the peak pressure of the Al / Fe2O3 / c-MnF2 pyrotechnic agent control sample in the comparative example 2-2 adding the conventional manganese difluoride as the energetic additive is only 0.81 MPa, and the pressure rise rate is 57 MPa / s, which is higher than that of the Al / Fe2O3 blank sample, but is still significantly lower than that of the Al / Fe2O3 / n-MnF2 pyrotechnic agent test sample, which further shows that the addition of the nano manganese difluoride as the energetic additive can effectively improve the pressure output performance of the pyrotechnic agent, and the improvement is unique to the nano manganese difluoride.
[0076] The above is only a specific embodiment of the present application, which cannot limit the scope of the present application, so the replacement of equivalent components or equivalent changes and modifications made within the scope of the present application should still belong to the scope of the present application. In addition, the technical features in the present application can be freely combined with each other, and the technical features can be freely combined with each other.
Claims
1. A pyrotechnic composition, characterized in that, The pyrotechnic composition comprises 20-50% of fuel, 40-70% of oxidizer and 3-10% of energetic additive, based on the total weight of the pyrotechnic composition; The energetic additive is nano manganese difluoride, which is in the form of particles with an average diameter less than 300 nm.
2. The pyrotechnic charge according to claim 1, characterized in that The fuel comprises one or a combination of several of aluminum powder, magnesium powder and boron powder.
3. The pyrotechnic charge according to claim 1 or 2, characterized in that The oxidizer comprises one or a combination of several of perchlorate, nitrate and metal oxide.
4. Process for the preparation of the pyrotechnic charge according to any one of claims 1 to 3, characterized in that, The preparation method comprises: adding the fuel, the oxidizer and the nano manganese difluoride into an organic solvent to uniformly ultrasonically disperse to obtain a mixture, and drying the mixture to remove the organic solvent in the mixture to obtain the pyrotechnic composition.
5. The preparation method according to claim 4, characterized in that, The preparation method of the nano manganese difluoride comprises: Step (1): mixing an alcohol solution of divalent manganese salt with an aqueous solution of ammonium hydrogen fluoride, and separating, washing and drying the generated precipitate to obtain an ammonium fluoromanganate precursor; Step (2): heating the ammonium fluoromanganate precursor to 350-450℃ in an inert gas environment and keeping the temperature to obtain the nano manganese difluoride.
6. The production method according to claim 5, wherein The divalent manganese salt comprises manganese nitrate and / or manganese bromide.
7. The production method according to claim 5 or 6, characterized by, The alcohol solvent used in the alcohol solution comprises methanol and / or ethanol.
8. The preparation method according to claim 5, characterized in that, The molar ratio of ammonium hydrogen fluoride to divalent manganese salt is 2-4:
1.
9. The production method according to claim 5 or 8, characterized by, The concentration of the alcohol solution of divalent manganese salt is 0.1-0.3 mol / L, and the concentration of the aqueous solution of ammonium hydrogen fluoride is 2-4 mol / L.
10. The production method according to claim 5 or 6, characterized by, The inert gas environment comprises nitrogen or argon.
11. The preparation method according to claim 4, characterized in that, The organic solvent comprises ethanol, isopropanol, acetonitrile or cyclohexane.
12. The production method according to claim 4 or 11, characterized by, The ultrasonic dispersion time is more than 1 h.
13. The preparation method according to claim 4, characterized in that, The drying is vacuum drying or freeze drying.
14. Use of the pyrotechnic composition according to any one of claims 1-3 in weapon equipment, ammunition system, aerospace, rescue equipment in blasting industry, automobile or gas propulsion.