Abstract:Smart munitions had been developed for many years and had no uniform definition yet.In this paper we interpreted the definition of smart munitions with the integration of some main definitions on board and at home. Based on the definitions, smart munitions were classified and some typical ones were introduced including course correcting munitions, guided munitions, terminal sensoring munitions, wide area munitions and loitering munitions, which were used widely in battlefield in recent decades. Key technologies of these munitions were pointed out and furture development of the munitions were expected.

Abstract:In order to obtain large transparent spherical-shaped RDX crystal, the metastable characteristics of RDX in water-cyclohexanone mixture solvent were studied. Solubilities and super-solubilities of RDX in water-cyclohexanone solution were tested by spectroscopy method, and the metastable zone width of RDX solution was determined. The correlation among temperature, water content and metastable zone width was discussed in detail. It is found that the metastable zone width becomes narrow when temperature rises: the metastable width is 16.4 ℃ in low temperature zone while 15.0 ℃ in high temperature zone when the water content is 8%, and the meta-stable width is 19.1 ℃ and 14.0 ℃ respectively when the water content is 4%. When temperature of RDX solution is above 58 ℃, the metastable width changes more wider when water content increases from 4% to 8%. The large transparent spherical particle RDX crystal, with 2 mm size and smooth surface, is obtained by adding the RDX crystal seed into water-cyclohexanone-RDX solution, which is in metastable state.

Abstract:A novel CL-20/TNT cocrystal explosive was prepared by cocrystallization in solution, and its morphology was characterized by scaning electron microscopy (SEM), and the crystal structure was determined using single crystal X-ray. Results show that the crystal is orthorhombic, space group Pbca with crystal parameters of a=0.9735(2) nm, b=1.9912(6) nm, c=2.4695(6) nm, α=β=γ=90°, V=4.787 nm³, Z=8. The thermal decomposition and impact sensitivity of the product were measured by differential scanning calorimetry (DSC) and sensitivity test, respectively. The results reveal that the exothermic decomposition of CL-20/TNT cocrystal explosive occurs in the temperature range of 180-275 ℃, and the melting point of TNT significantly increases by about 50 ℃. CL-20/TNT cocrystal has lower impact sensitivity and the impact sensitivity of CL-20 obviously reduces by 87%.

Abstract:The desensitizing technology of high-quality HMX were studied by coated with wax (W) or thermoplastic polyurethane (TPU) as insensitive coating additive. The feasibility study of high-quality HMX coated by W and TPU were proved through contact angle and surface energies. Then the samples were characterized by using SEM and XPS. The mechanical sensitivity of HMX samples before and after coating was measured and compared. The coating integrality and desensitizing effect of D-HMX coated by W in water and non-agueous media (Novec 7200), respectively. The results show that the high-quality HMX are coated entirely by W and TPU and the impact and friction sensitivity of high-quality HMX coated by W decreases significantly from 88% to 16%, from 92% to 4%, respectively. It indicats that D-HMX is coated entirely and more insensitive which the impact sensitivity fall to 0% while coated in non-aqueous media (Novec 7200) than in water.

Abstract:1-Methyl-2, 4-dinitroimidazole(2, 4-MDNI) was synthesized via nitration, thermal rearrangement and methylation with imidazole as primary material. The single crystal of 1-methyl-2, 4-MDNI was cultivated in acetone and its crystal structure was determined by a four-circle X-ray diffractometer. The results indicate that the crystal is orthorhombic, space group P₂₁₂₁₂₁, with crystal parameters: a=6.215(12)Å, b=9.431(19)Å, c=23.531(5)Å, V=1379.3(5)ų, α=β=γ= 90°, D_c=1.658 g·cm^-3, Z=8, F(000)=704 and μ=0.149 mm^-1. The results reveal that 2, 4-MDNI has good thermal stability, and exhibits different thermodynamic behavior under different conditions.

Abstract:Furazano[3, 4-e]-1, 2, 3, 4-tetrazine-1, 3-dioxide(FTDO) has been synthesized in the work. Firstly, diaminoglyoxime(DAG) was obtained via the one-step reaction of glyoxal with hydroxylammonium chloride. 3, 4-Diaminofurazan(DAF) was obtained by the dehydration reaction of DAG. Then the oxidation of DAF using 30% H₂O₂ gave 3-amino-4-nitrosofurazan(ANF), and 3-amino-4-(tert-butyl)azoxyfurazan was prepared after the treatment of ANF with tert-butyl-N, N-dibromide in dichloromethane. Finally, FTDO was obtained by the nitration and cyclization of 3-amino-4-(tert-butyl)azoxyfurazan with nitronium tetrafluorobrate (NO₂BF₄) in acetonitrile with the total yield of 18%. The structures of FTDO and its intermediates were characterized by IR and NMR.

Abstract:Furazano[3, 4-e]-1, 2, 3, 4-tetrazine-1, 3-dioxide(FTDO) was investigated by theoretical methods. Its optimized geometry structure, IR spectrum, and heat of formation were calculated using density functional theory with B3LYP/6-31+G(d, p) level and G2 method. The density and oxygen balance of FTDO were also estimated theoretically. The density is 1.860 g·cm^-3, oxygen balance is -10.25%. The heat of formation of FTDO is 661.0 kJ·mol^-1. The explosion parameters of FTDO were calculated and compared with that of HMX. The specific volume of explosion, detonation velocity, and detonation pressure of FTDO are 718 L·kg^-1, 9493 m·s^-1, and 40.76 GPa respectively. Except for the density and specific volume of explosion, all of other properties of FTDO are better than those of HMX.

Abstract:Characteristics of phase transition, thermal behavior and kinetics of non-isothermal decomposition of 4′4-bis-1, 2, 4-triazole (BTz) were studied using in-situ X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetry (TG). The results show that, at around 170 ℃, the solid-solid phase transition is detected at a heating rate of 10 ℃·mol^-1, followed by the melting starting at about 270 ℃ and the peak temperature of thermal decomposition of BTz is 290.0 ℃. The phase transition of BTz is reversible according to the result of in-situ XRD and DSC. Based on the detected decomposition temperatures at various heating rates (β), the decomposition temperature at the heating rate approach to zero was derived with the value T_p0=256.3 ℃. By means of Kissinger method and Ozawa method, the calculated activation energies (E_a) are 224.7 kJ·mol^-1 and 222.4 kJ·mol^-1, and pre-exponential factors (A) are 6.31E+20 s^-1 and 3.98E+20 s^-1, respectively.

Abstract:In order to study the characteristics and calculation method of interior ballistic with the low temperature sensitivity coated propellant charge, the parameters at the potential equilibrium point with standard charge and the low temperature sensitivity coated propellant charge were compared by the potential equilibrium theory. The reason why ψ_E (the relative amount of burned propellant) at the potential equilibrium point changed with the charge density was analyzed and the actual burning gas formation function was fitted. The simulation of the interior ballistic was carried out based on the above. The results show that the calculated curve is in good agreement with the experimental curve and the potential equilibrium theory can be used to study the combustion laws of the low temperature sensitivity coated propellant charge.

Abstract:By use of three-dimensional nonlinear dynamic finite element program LS-DYNA, a series of numerical simulations of pelletrator with enhanced lateral effect (PELE), which had the same projectile structure and material, pentetrate different metal targets with the same velocities (900~1300 m·s^-1) were presented. The simulation results were compared with the experimental and in good agreement with the experimental data. The corresponding theoretical analysis between the results of simulation and experiment shows that the process of the inertia compression has much to do with the effect for PELE, and the PELE has better lateral effect with the increasing of density and bulk modulus of the target.

Abstract:To study the influence of initiation point position on formation of circle-shaped multiple explosively formed projectile (MEFP), numerical simulation of the forming process of the circle-shaped MEFP was carried out with the ALE method using LS-DYNA, and the influence of the cutting reseau distance on radial dispersion angle was analyzed. Results indicate that such a charge structure can produce five pieces of sub-explosively formed projectile which has a definite mass, direction, and a velocity between 1600 m·s^-1 and 2 400 m·s^-1. Under fixed cutting reseau distance, with the increase of initiation point distance, the speed of MEFP increases, the radial dispersion angle of MEFP reduces gradually. The initiation point distance should be in a proper range from 0.56 to 0.89 times as long as D_k (D_k is the charge caliber) in order to form ideal sub-explosively formed projectile, and it has a best formation at 0.78 D_k.

Abstract:5-Amino-3-nitro-1, 2, 4-triazole (ANTA) was important propellant as an insensitive explosive. The impact insensitivity of ANTA was higher than 320 cm(Type12), and its the detonation velocity was about 8460 m·s^-1 (ρ=1.819 g·cm^-3). In addition, the structure of ANAT has two reaction centers, -NH and -NH₂, which take part in many reactions such as alkylation, arylation, diazotizotion, oxidation, ionization and so on and can be an intermediate with various compounds to synthesis many insensitive high explosives. This review focused on structure characteristics, synthesis routes and the reactive sites of ANTA. A general summany was also made on the reaction rules of ANTA to provide a reference for synthesising new insensitive high energitic materials or high nitrogen energetic salts.

Abstract:In order to extend the application of 2, 6-diamino-3, 5-dinitropyrazine-1-oxide (ANPZO), three different ANPZO crystallines with cubic, needle and ultrafine shape were obtained by recrystallization and pneumatic spray refining. Some sensitivities and performance of ANPZO explosive were characterized, such as shock wave sensitivity, mechanical sensitivity, thermal behavior and detonation velocity. Results show that the shock wave sensitivities for different ANPZO crystal shapes are nearly the same with approximate 3.65mm in D₅₀. The mechanical sensitivity of cubic ANPZO crystal is lower than that of other crystals. ANPZO is thermally stable with maximum heat release peak value of 350 ℃, the 5 s delay explosion temperature as 302 ℃ and the decomposition temperature as 305 ℃ in slow cook-off test. Detonation velocity measured is up to 8070 m·s^-1 with the density of 1.855 g·cm^-3.

Abstract:Sodium tetra(5-nitrotetrazolate) diaquate ferrate(Ⅱ) (NaFeNT) was synthesized from sodium 5-nitrotetrazolate ferrous chloride with temperature 98-100 ℃ and circumfluence time 3 h. The color of crystal is orange. The structure was characterized by elemental analysis, scanning electron microscopy, energy dispersive spectrometry, and Fourier transform infrared. The thermal properties (DSC, explosive temperature), stability properties (hygroscopicity, vacuum stability), explosive properties (explosion heat, specific volume, detonation velocity, impact, friction, flame, electrostatic spark sensitivity) and wastewater treatment method were studied. The results show that the thermal decomposition peak of NaFeNT is 258 ℃ and 5 s explosive temperature is 278 ℃. The hygroscopicity capacity is 3.58% under 30 ℃/120 h and decomposition gas capacity is 0.17 mL·g^-1 under 100 ℃/ 40 h/vacuum. Explosion heat, detonation velocity and specific volume are 3929 J·g^-1, 5550 m·s^-1, 506 mL·g^-1, respectively. NaFeNT is insensitive to impact, electrostatic spark and sensitive to friction. Its flame sensitivity is 76% with 2 cm.

Abstract:Thermal behaviours of graphite/potassium nitrate (C/KNO₃) with different proportion were studied by TG-DSC technique. The kinetic parameters of thermal decomposition reaction for C/KNO₃=90/10 mixture were calculated by Friedman′s method. Results show that thermal decomposition of C/KNO₃ is solid-phase reaction. At the same heating rate, propotion and the decomposition characteristics are different. At different heating rates, propotion is same but the decomposition characteristics are also different. C/KNO₃ decomposition process is very complex with three or more reactions. Activation energy of the main decomposition reaction is between 102.84~374.27 kJ·mol^-1 and the pre-exponential factor between about 3.25~10.39 s^-1.

Abstract:The heat release law of the synthesis process of ADN was determined using reaction calorimeter RC1e. The technical process comprises four stages: neutralization, mixing of nitric acid and sulfuric acid, nitration under lower temperature and amination. At the same time, the reaction thermodynamic data including heat transfer coefficient, heat capacity were determined. Results show that, with the corresponding reaction system, the reaction heat of four stages are 580, 43.07, 207.1, 302.99 kJ, and the average heat release rate are 188.44, 12.22, 33, 125.41 W, and the adiabatic temperature rise(ΔT_ad) are 123.25 K, 19.40 K, 126.53 K and 91.48 K.

Abstract:The combustion properties of RbNO₃ infrared pyrotechnic composition comprising RbNO₃ as oxidation agent, hexafluoropropenevinylidenfluoride-copolymer(FPM) as binding agent and Mg, Al₃Mg₄, Ti, TiH₂ and B as combustion agent, respectively were studied. DSC was used to analyse the decomposition process of the pyrotechnic composition.The combustion heat and flame temperature were measured and then compared with the results calculated by REAL method. The ingrared radiation intensity of 0.7~1.1 μm and visible light intensity of 0.4~0.7 μm were measured. Results show that the decomposition process of B/RbNO₃/FPM and TiH₂/RbNO₃/FPM pyrotechnic composition is the same. The value of combustion heat of Mg/RbNO₃/FPM pyrotechnic composition is the highest which is 4939 kJ·kg^-1, and then the order is Mg > Al₃Mg₄ > TiH₂ > Ti > B. The flame temperature of Ti/ RbNO₃/FPM is the highest which is over 2700 ℃ and the measured flame temperatures are lower than those of calculation by REAL method. The Ti/ RbNO₃/FPM ratio of infrared radiation intensity of 0.7~1.1 μm and visible light intensity is 1.654 which is much higher so that TiH₂/PTFE/FPM can be used as good infrared illuminating composition.

Abstract:Four kinds of nano-ferric-oxide Ⅰ-Ⅳ with different appearance and five kinds of 9~14/65-70/17/3/1-adhesive /AP/Al/ferrocence/ordinary ferric-oxide or nano-ferric-oxide Ⅰ-Ⅳ propellants (HTPB propellant) were prepared. The effect of nano-ferric-oxide on the mechanical performances, combustion characteristics and safety properties of HTPB propellant were studied. Results show that nano-ferric-oxide Ⅱ is the best catalyst of the four kinds of nano-ferric-oxide. At 25 ℃, the maximum tensile strength of HTPB propellant with nano-ferric-oxide Ⅱis about 0.83 MPa and its maximum elongation reaches 60%. At -40 ℃, its maximum tensile strength is about 2.00 MPa and the maximum elongation reaches 45%. The burning rate at 6.86 MPa is 43.24 mm/s and the pressure exponent is 0.27. The critical impact energy of 50% explosive (I₅₀) of the propellant slurry is greater than 14 J and the friction sensitivity is less than 80%, indicating that the safety properties of the propellant are same as those of the propellant with ordinary ferric-oxide.

Abstract:The safety performane of explosive is investigated by analyzing three responses for spigot test: initiation, ignition and fragmentation. In this paper, the numerical model of spigot test was developed with high sensitive explosive JO-9159 and low sensitive PBXC03. The Ignition and Growth reactive (I and G) model was used to describe initiated progress. The thermal-mechanical coupling method and Arrhenius equation were used to describe ignited temperature. The elements-apart method was used to describe fragmentation of explosive. The calculated critical drop velocity is between 25 m·s^-1 and 28 m·s^-1, which is agreement with experimental results, and interior temperature and fragmentation of explosive were gained.

Abstract:The thermal explosion temperature (T_b) was determined by heat explosion test and the drop height (H₅₀) was obtained by impact sensitivity test for 12 types of RDX-based aluminized explosives with different contents of RDX and aluminum powder respectively. The heat explosion parameters decreased to the lowest when RDX content reaches 89%(T_b, heat explosion activation energy(E_b) and logarithm of pre-expontential factor(lnA)), and drop energies (E_dr) were calculated with experiment data. The results show that the drop height (H₅₀) first fall down and then rise with the increasing of RDX contents. Additionally, it is found that a linear relationship exists between the drop energies (E_dr) and heat explosion parameters (T_b, E_b and lnA).

Abstract:In order to study combustion performance of the modified single base propellant composed of 5/7 single base propellant as base, NG as dipping reagent and polyester as coat regent, a theoretical analysis and an experimental validation for the dipping layer distribution in grain, the changes of grain size and energetic characteristic in combustion process have been studied. Two samples with 10% and 15% NG dipping quantity were prepared. Closed bomb test and micrograph observation of grain slices were done, and a calculation for the experimental results was carried out with the found model. Results show that the impetus of the sample containing 15% NG dipping reagent increases by 10.14%, and dipping depth is about 0.168 mm. The u-p curves of the single base propellant obtained by calculation is higher than that of the modified single base propellant before 150 MPa, and the u-p curves of both overlap with each other after 150 MPa. As long as the dipping reagent ratio of NG to polyester is appropriate, both impetus and progressive burning performance of the modified can get increasing within a certain range. Both impetus and progressive burning performance of the modified single base propellant can be increased within a certain range.

Abstract:The Grey relationship degree of NEPE solid propellant sensitivities was calculated by numerical method, including impact sensitivities, friction sensitivities, flame sensitivities and other sensitivities from composing and granularities. The results indict that plasticization ratio is the main influence factors of friction sensitiity and regional thermal sensitiity. The contants of HMX is the main influence factors of Shock sensitivity and 5 s explosion temperature, S is the main influence factors of impact sensitivity electrostatic spark sensitivity and flame sensitivity. Granularities result indict that particle size of Al is the main influence factors of friction sensitiity, 5 s explosion temperature and flame sensitivity. The particle size of AP is the main influence factors of regional thermal sensitiity and electrostatic spark sensitivity, particle size of HMX is the main influence factors of impact sensitivity.

Abstract:Determination test of the reliability of air gap detonation transmission interface was designed through air gap length as variable and testing device were constructed. The reliability of air gap detonation transmission interface composed of including detonator, air gap and detonating explosive in partition initiator was tested and estimated by Neyer-D Optimized method. Results show that the critical functioning length of air gap is 18.76 mm. The reliability of the interface function obtained by interval estimation of p quantile is 0.999925 at confidence level of γ=0.95.

Abstract:In order to predict the explosion energy of aluminized explosives, a non-ideal detonation energy predicting mode after theoretical analysis was built and the software by matlab software, numerical iteration and numerical preparation was developed. The software is suitable for aluminized explosive C-J pressure, C-J velocity predicting of some common aluminized explosives such as H-6, HBX-1, Alex 20, Alex 32, Tritonal and Torpex. The detonation parameters and explosion energy calculated by the software agree well with empirical results and all of the deviations of aluminized explosives are less than 8%, which is useful for the explosion energy prediction of aluminized explosives.

Abstract:The surface micro-structure of an explosive part affects its performance, measured precision of the part, and reliability of the weapon parts. The 3D surface micro-structure of the pressed PBX lathed surfaces was detected. The 3D and 2D surface roughness parameters were evaluated and analyzed. The results show that 3D surface roughness parameter is suitable for evaluating PBX machined surface with random distribution caving and pits defects. The 3D surface roughness parameter evaluation is better than that of 2D surface roughness parameter. Under the same evaluating parameters, PBX 3D surface roughness using round tool is much less than that using standard tool. The feed affects surface roughness greatly, while the spindle speed affects surface very little.

Abstract:In order to understand the microstructures of ammonium nitrate-oil explosives(ANFO) and their effects on detonator initiation sensitivity, different types of ANFO were made from fuel oil and four different states AN, and the scanning electric microscopy (SEM) and density measuring method were both used to characterize their microstructures. Then, the section technique was used for the first time to observe their intragranular microstructures, and plate dent test was conducted to evaluate the detonator initiation sensitivity. Results show that unexpanded ANFO particles have few pores and cracks inside and outside of the particles, and its surface is more smoother than that of expanded ANFO particles. While expanded ANFO particles have many holes and cracks, there are abundant voids and twin crystals lying in the interior of expanded ANFO particles, and the growth of crystals is incomplete. The microstructures of porous particles and protruding particle surface are helpful to enhance the detonator initiation sensitivity of ANFO.

Abstract:In order to solve the problems of poor homogeneity and unstable explosion property of low detonation velocity explosive used in explosive welding. Ammonium nitrate was mixed with microcrystalline, octadecylamine acetate, diluents, and water at 115~125 ℃, and it was dehydrated at -0.07~-0.09 MPa. The thermal safety, microstructure and mechanical sensitivity were analyzed, the effect of the explosive layout thickness on detonation velocity was also studied, and the explosive welding test on aluminum-steel plate was done. The results show that the component has a good the mixing uniformity, the mechanical sensitivity is low, the detonation velocity is 1900~2400 m·s^-1, and the recombination rate of ultrasonic flaw detection is up to 99%, which can satisfy the requirement of explosive welding of metal plate.

Abstract:A post chemiluminescence(PCL) phenomenon was observed when unsymmetrical dimethyl hydrazine(UDMH) solution was injected into a solution after the finish of CL reaction of alkaline luminol and potassium periodate. A new method for the determination of trace UDMH was established based on the studies of the CL reaction conditions including the concentration of potassium periodate and luminol,the length of tube,the velocity of solution flow,the luminal alkalinity(NaOH) and other experiments. The linear response range of this method was from 1.0×10^-6 to 1.0×10^-4 g·L^-1 with a detection limit of 3.3×10^-7 g·L^-1. The relative standard deviation for 4.0×10^-6 g·L^-1 UDMH solution was 2.7% for 11 tests. This method has been used to determine UDMH in water with satisfactory results. The PCL mechanism is also discussed briefly.

Abstract:On the basis of the unsymmetric dimethydrazine (UDMH)-degrading bacteria preserved in laboratory, the compound flora FYD was build with a view to use in the emergency situations when UDMH leaked into water. The optimal conditions for degradation of UDMH determined by effect factors experiments are as following: temperature 35 ℃, the medium pH 7.2, inoculation 2%, the initial UDMH concentration 50 mg·L^-1. Under this condition, the highest UDMH degradation rate, is 99.10%, and UDMH residual concentration is less than 0.5 mg·L^-1 in 72 h, and all the indicators of water meet the requirements of GB1473-93 emission standards.

Abstract:The development and application of cyclophosphazene and polyphosphazene compounds in energetic materials in recent years were classifiedly reviewed. Some synthesis and research trends of phosphazene-energetic materials were introduced. Spiro-, azide-and spiro-azide energetic cyclophosphazene compound are the three most important hazard primary explosives which have attracted more and more attention due to their excellent performance and distinctive structure characteristics. Azide-and nitric polyphosphazene will be of important significance to development environment-friendly energetic binders because of higher energy density and decomposition energy compared to conventional ones.

Abstract:Non-metallic energetic ionic compounds of tetrazolate anion are a kind of insensitive energetic materials. The progresses in the insensitive non-metallic energetic salts of aminotetrazolate, nitrotetrazolate, nitraminotetrazolate, azotetrazolate and furazan fuctionalized tetrazolate anions were reviewed in detail. It is found that most of ionic compounds based on tetrazolate anions which contain traditional energetic functionalities upon the carbon of positon 5 such as nitro and nitrimino functionalities, show high sensitivities, while the sensitivities of ionic compounds based on 5-aminotetrazolate, 5, 5′-azotetrazolate and 5-(4-aminofurazan-3-yl)tetrazolate are so low that they can be used as insensitive energetic materials. Furthermore, new trends in research of insensitive non-metallic energetic ionic compounds of tetrazolate anion were proposed.

Abstract:3, 6-Bis(3, 5-dimethylpyrazol-1-yl)-1, 2, 4, 5-tetrazine (BT) was prepared by oxidation of 3, 6-bis(3, 5-dimethylpyrazol-1-yl)-1, 2-dihydro-1, 2, 4, 5-tetrazine (BDT) with NO₂. The single crystal was cultured in anhydrous alcohol using slow evaporation method, and was determined by X-ray diffraction analysis. The molecule belongs to monoclinic system, space group P₂(1)/c, with crystal parameters of a=1.096 nm, b=1.651 nm, c=0.714 nm, β=103.895(4) °, Z=4.

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