Nitramine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive

Abstract

The invention discloses a nitramine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive which comprises the following components in percentage by weight: 49-51% of nitramine compound, 26-34% of potassium perchlorate and 17-23% of zinc-magnesium alloy powder, the mass fraction of magnesium in the zinc-magnesium alloy powder is 50%, and the zinc-magnesium alloy powder is prepared by adding Zn powder into Mg powder through a centrifugal atomization method. The high-energy insensitive explosive disclosed by the invention is high in exothermic peak temperature and good in thermal safety; meanwhile, heat release is concentrated and large, and the characteristic of high energy release rate is achieved; the impact sensitivity and the friction sensitivity of the formula are low, and the mechanical safety is good.

Description

Technical Field

[0001] The present invention relates to the technical field of propellants and explosives, and particularly to a high-energy insensitive explosive of nitramine compound / potassium perchlorate / zinc-magnesium alloy. Background Art

[0002] Among single-component explosives, compounds containing the –N–NO 2 group are called nitramine compounds (such as RDX, CL-20, HMX, etc.). Such compounds usually exist in the form of high-purity microcrystals or ultrafine powders, and have high heat of explosion, detonation velocity and detonation pressure. They are one of the most widely used industrial explosive varieties. However, explosive nitramine compounds such as RDX, CL-20 and HMX have high thermal sensitivity and mechanical sensitivity, and are prone to ignition and explosion when encountering accidental stimuli such as fire, impact, and ammunition attack. Moreover, their volume combustion enthalpy and energy density are relatively low, and these disadvantages limit their application in the industrial field.

[0003] To meet the requirements of high damage power and safety of explosives, high-energy insensitive composite explosives mainly composed of explosive nitramine compounds, strong oxidants and metal powders have become a research hotspot for scholars at home and abroad in recent years. Ammonium perchlorate, as an oxidant widely used in high-energy composite explosives, although it has a high oxygen content and good energy characteristics, its impact sensitivity and friction sensitivity are relatively high, and it is prone to accidental reactions under mechanical stimulation; moreover, ammonium perchlorate has high hygroscopicity and poor chemical stability, which is not conducive to long-term storage. In addition, Al powder and Mg powder are often introduced into high-energy composite explosives as metal fuels to increase the heat of explosion and extend the pressure duration. However, the chemical properties of Al and Mg are active and they are easily oxidized, and the oxide shell formed on their surfaces will hinder the contact with the oxidant and reduce the combustion efficiency. Summary of the Invention

[0004] Aiming at the defects or deficiencies of the prior art, the present invention provides a high-energy insensitive explosive of nitramine compound / potassium perchlorate / zinc-magnesium alloy, which reduces the sensitivity of nitramine explosives while improving their energy release performance.

[0005] For this purpose, in a first aspect, the present invention provides a high-energy insensitive explosive of nitramine compound / potassium perchlorate / zinc-magnesium alloy, which is a mixture composed of an explosive nitramine compound, potassium perchlorate and zinc-magnesium alloy powder.

[0006] Further, the nitramine compound is any one of RDX, CL-20, and HMX.

[0007] Further, the zinc-magnesium alloy powder is prepared by adding Zn powder to Mg powder through centrifugal atomization.

[0008] Further, the mass fraction of the nitramine compound is 49-51%, the mass fraction of potassium perchlorate is 26-34%, and the mass fraction of the zinc-magnesium alloy powder is 17-23%.

[0009] Further, the mass fraction of magnesium in the zinc-magnesium alloy powder is 50%.

[0010] Further, the particle size range of the zinc-magnesium alloy powder is 70-150 μm.

[0011] Further, the zinc-magnesium alloy powder is prepared by the following steps:

[0012] S1. Uniformly mix zinc powder and magnesium powder in a furnace of a centrifugal atomization system;

[0013] S2. Pump the furnace chamber to vacuum and backfill with a protective gas as the shielding gas;

[0014] S3. Heat the mixture composed of zinc powder and magnesium powder to 700-800 °C to melt it;

[0015] S4. Transport the melt to a high-speed rotating atomization disk. Under the action of centrifugal force, the melt forms small droplets after passing through a cooling tower and then solidifies into a zinc-magnesium alloy;

[0016] S5. Screen and collect powders with a particle size of 70-150 μm to obtain the zinc-magnesium alloy powder.

[0017] Furthermore, in step S2, the vacuum degree required for pumping the furnace chamber to vacuum is 10 -3 ~10 -2 Pa, and the protective gas is one of pure argon (99.99%), pure nitrogen (99.99%) or pure helium (99.99%).

[0018] In a second aspect, the present invention simultaneously provides a preparation method of the nitramine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive described in the first aspect, including the following steps:

[0019] Disperse the nitramine compound, potassium perchlorate and the zinc-magnesium alloy powder in an organic solution and ultrasonically treat for 30-60 min; after filtration, place it in a fume hood for 18-24 h to obtain the nitramine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive.

[0020] Further, the organic solution is propanol or ether.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] The results of the thermal performance tests show that the main exothermic peak temperatures of the formulations of the present invention are all at 440.72 °C or above, significantly reducing the thermal sensitivities of RDX and CL-20 and having good thermal safety. In addition, the formulations of the present invention have concentrated heat release and a large heat release amount, featuring a high energy release rate.

[0023] The results of the mechanical sensitivity tests show that the impact sensitivities of the formulations of the present invention are all at 35 J or above, and the friction sensitivities are all at 30% or below, significantly reducing the mechanical sensitivities of RDX and CL-20 and having good mechanical safety.

[0024] Among them, the zinc-magnesium alloy powder prepared by the centrifugal atomization method has high purity, good sphericity, narrow particle size distribution, uniform zinc distribution, and this method has low cost and high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the advantages of the present invention and the technical solutions of the embodiments, the present invention will be described in detail below in conjunction with the drawings and specific embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0026] Figure 1 is the TD-DSC curve of RDX / potassium perchlorate / zinc-magnesium alloy prepared in Example 1;

[0027] Figure 2 is the TD-DSC curve of CL-20 / potassium perchlorate / zinc-magnesium alloy prepared in Example 2. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following further describes the present application in conjunction with specific embodiments.

[0029] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" cited in this specification are only for the convenience of narration and are not used to limit the scope of implementation. The change or adjustment of their relative relationships shall also be regarded as the scope of implementation of the present application without substantial change in the technical content.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0031] For those conditions not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0032] As used herein, the term "about" is used to provide flexibility and imprecision associated with a given term, measurement, or value. A person skilled in the art can readily determine the degree of flexibility for a particular variable.

[0033] As used herein, the term "at least one of..." is intended to be synonymous with "one or more of...". For example, "at least one of A, B, and C" specifically includes only A, only B, only C, and their respective combinations.

[0034] Concentrations, amounts, and other numerical data may be presented herein in a range format. It should be understood that such range formats are used merely for convenience and brevity and should be interpreted flexibly as including not only the numerical values explicitly recited as the limits of the range, but also all individual numerical values or sub-ranges subsumed within the stated range as if each numerical value and sub-range were explicitly recited. For example, a numerical range of about 1 to about 4.5 should be interpreted as including not only the explicitly recited limit values of 1 to about 4.5, but also the individual numbers (such as 2, 3, 4) and sub-ranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that recite only one numerical value, such as "less than about 4.5", which should be interpreted as including all of the above values and ranges. In addition, this interpretation should apply regardless of the breadth of the range or feature being described.

[0035] The concept of the present invention is that: compared with ammonium perchlorate, potassium perchlorate has higher chemical stability and lower hygroscopicity, which is beneficial to the long-term storage of explosives; potassium perchlorate has higher thermal stability, and its decomposition temperature is more than 200 °C higher than that of ammonium perchlorate; potassium perchlorate has stronger oxygen supply ability, which can reduce the addition amount of oxidizer and improve the energy density of the formulation; potassium perchlorate has lower mechanical sensitivity, which is beneficial to reducing the risk of explosives during processing and transportation. In the present invention, zinc-magnesium alloy is added to the high-energy insensitive explosive instead of zinc powder / magnesium powder, and the reason is that: zinc and magnesium are chemically active and easily oxidized, and the oxide shell formed on their surface will hinder the contact with the oxidizer and reduce the combustion efficiency. Moreover, the melting point and boiling point of zinc are both lower than those of magnesium, and the saturated vapor pressure of zinc is more than 10 times higher than that of magnesium at 600 °C and 900 °C. This indicates that zinc is easy to melt and vaporize. Adding zinc to magnesium to prepare zinc-magnesium alloy can effectively break through the oxide shell on the surface of metal powder and promote the diffusion process of magnesium, thereby improving the energy output and energy release rate of composite explosives.

[0036] Example 1

[0037] The preparation raw materials of this example are as follows: RDX 50%, potassium perchlorate 30%, zinc powder 10%, magnesium powder 10%;

[0038] The preparation method of the zinc-magnesium alloy in this example is as follows: 10 g of zinc powder and 10 g of magnesium powder are mixed evenly in a furnace within a centrifugal atomization system. Subsequently, the furnace chamber is evacuated to a vacuum (10 -2 Pa), and backfilled with pure argon (99.99%) as the protective gas; the temperature inside the furnace chamber is raised to 750 °C to melt the zinc powder and magnesium powder. The melt is transported to the atomization chamber through a conveying pipeline and then enters a high-speed rotating atomization disk through a diversion pipe; under the action of centrifugal force, the melt forms small droplets after passing through a cooling tower and then solidifies into a magnesium-zinc alloy; the magnesium-zinc alloy powder with a particle size of 100 μm is screened and collected to obtain the zinc-magnesium alloy of this example.

[0039] The preparation method of the nitroamine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive in this example is as follows: 50 g of RDX, 30 g of potassium perchlorate, and 20 g of zinc-magnesium alloy are dispersed in propanol and ultrasonicated for 40 min; after filtration, it is placed in a fume hood for 24 h to obtain the RDX / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive of this example.

[0040] Example 2

[0041] Different from Example 1, this example is implemented according to the following mass percentage composition: CL-20 50%, potassium perchlorate 30%, zinc powder 10%, magnesium powder 10%;

[0042] The preparation method of this example refers to Example 1.

[0043] Further, the following performance tests are carried out on the products prepared in the above examples:

[0044] (1) Ignition performance and thermodynamic reaction process test. The test method is as follows:

[0045] Tested using a TG-DSC instrument from Mettler Toledo. Each time, 0.5 mg of the sample is added to the crucible and placed in the furnace body; high-purity nitrogen is used as the protective gas (gas flow rate is 20 mL / min) and air is used as the reaction gas (gas flow rate is 50 mL / min) inside the furnace body; the measurement temperature range is 50 - 800 °C, and the heating rate is 10 °C / min. The temperature, heat, and weight changes of the sample during the heating process are measured. The program control, data recording, and analysis are all completed by the STARe Software 10.0 software developed by Mettler.

[0046] The TG-DSC test results of the nitroamine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosives prepared in Example 1 and Example 2 are as Figures 1 to 2 shown. Existing technologies show that at a heating rate of 10 °C / min, the main exothermic peak temperature of RDX is between 230 - 240 °C, and the main exothermic peak temperature of CL-20 is between 240 - 260 °C. From Figure 1 and Figure 2It can be seen that the exothermic peak temperature of the RDX / potassium perchlorate / zinc-magnesium alloy of the present invention can be significantly increased to 440.72 °C, and the peak heat release is 14.31 mW; the main exothermic peak temperature of the CL-20 / potassium perchlorate / zinc-magnesium alloy can be significantly increased to 488.40 °C, and the peak heat release is 15.07 mW; and the heat release of the two formulations is concentrated and the energy release rate is high.

[0047] (2) Impact sensitivity test, the test method is as follows:

[0048] The BAM drop hammer impact sensitivity tester is used for the test, and the impact sensitivity of the sample is characterized by the impact energy method. The smaller the impact energy, the greater the impact sensitivity of the sample. The test is carried out in accordance with Method 601 of GJB772A-1997.

[0049] (3) Friction sensitivity test, the test method is as follows:

[0050] The BAM friction tester is used for the test, and the friction sensitivity of the sample is characterized by the explosion percentage. The larger the explosion percentage, the greater the friction sensitivity of the sample. The test is carried out in accordance with Method 602 of GJB772A-1997.

[0051] The test results of the impact sensitivity and friction sensitivity of the products prepared in the above examples, as well as RDX and CL-20, are shown in Table 1.

[0052] As can be seen from Table 1, compared with RDX, the impact sensitivity of the RDX / potassium perchlorate / zinc-magnesium alloy of the present invention is significantly increased from 7.5 J to 35 J, and the friction sensitivity is significantly decreased from 60% to 25%; compared with CL-20, the impact sensitivity of the CL-20 / potassium perchlorate / zinc-magnesium alloy of the present invention is significantly increased from 12 J to 40 J, and the friction sensitivity is significantly decreased from 70% to 30%.

[0053] Table 1

[0054]

[0055] The above-mentioned implementation cases are only the better implementation cases in the present invention, but the implementation manners of the present invention are not limited by the above

[0056] mentioned implementation cases. For example, various forms of combinations of the solutions in the examples, any other changes, modifications, substitutions, and combinations made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all within the protection scope of the present invention.

Claims

1. A nitramine compound / potassium perchlorate / zinc-magnesium alloy high energy insensitivity, characterized in that: It is a mixture of explosive nitramine compounds, potassium perchlorate and zinc-magnesium alloy powder.

2. The high energy insensitivity according to claim 1, characterized in that: The nitramine compound is any one of RDX, CL-20 and HMX.

3. The high energy insensitivity as claimed in claim 1, characterized in that: The mass fraction of the nitramine compound is 49-51%, the mass fraction of potassium perchlorate is 26-34%, and the mass fraction of the zinc-magnesium alloy powder is 17-23%.

4. The high energy insensitivity according to claim 1, characterized in that: Zinc-magnesium alloy powder is prepared by adding Zn powder to Mg powder through centrifugal atomization.

5. The high energy insensitivity according to claim 1 or 4, characterized in that: The mass fraction of magnesium in the zinc-magnesium alloy powder is 50%.

6. The high energy insensitivity according to claim 1 or 4, characterized in that: The particle size of the zinc-magnesium alloy powder ranges from 70 to 150 μm.

7. The high energy insensitivity according to claim 1 or 4, characterized in that: The zinc-magnesium alloy powder is prepared by the following steps: S1. Evenly mix zinc powder and magnesium powder in a furnace in a centrifugal atomization system; S2, evacuate the furnace to vacuum and backfill with protective gas; S3, heating the mixture of zinc powder and magnesium powder to 700-800° C. to melt the mixture; S4, the melt is transported to a high-speed rotating atomizing disk. Under the action of centrifugal force, the melt passes through a cooling tower to form small droplets, and then solidifies into a zinc-magnesium alloy; S5. Screen and collect powders with a size of 70 to 150 μm to obtain the zinc-magnesium alloy powder.

8. The high energy insensitivity according to claim 7, characterized in that: In step S2, the vacuum degree required to be achieved in the furnace is 10 -3 ~10 -2 Pa, the shielding gas is one of pure argon, pure nitrogen or pure helium.

9. A method for preparing the nitramine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive as claimed in any one of claims 1 to 8, characterized in that: The steps include: The nitramine compound, potassium perchlorate and the zinc-magnesium alloy powder are dispersed in an organic solution, and ultrasonicated for 30 to 60 minutes; after filtering, the solution is placed in a fume hood for 18 to 24 hours to obtain a nitramine compound / potassium perchlorate / zinc-magnesium alloy high-energy insensitive explosive.

10. The method according to claim 9, characterized in that The organic solvent is propanol or ether.

Images