Abstract:To obtain the rules of jet penetrating spaced target with water interlayer,theoretical and experimental research were performed selecting the penetrating process of 50 mm caliber shaped charge penetrating spaced target with water interlayer (2 mm×4 mm steel plates +100 mm water interlayer). The theoretical model of jet penetrating spaced target with water interlayer was established by quasi-steady penetration theory and mathematical induction,the relationship of jet tip velocity and penetration distance was got. To validate the theoretical model,jet tip velocities of multiple stages were obtained by X-ray pulsed and timing device. The influence of spaced target with water interlayer to the remaining jet tip velocity was analyzed through theoretical model. The results show that the theoretical model is correct,after penetrating spaced target with water interlayer,the average error of remaining jet tip velocity between theoretical and experimental values is 4.6%.The attenuation efficiency of jet tip velocity by spaced target with water interlayer is higher when the target thickness is less than 20 mm and water separation distance is less than 150 mm.

Abstract:The mechanical properties of hydroxyl terminated polyisobutylene(HTPB)-based polyurethane cured by a new mixed curing agent composed of isophorone diisocyanate (IPDI) and dimeryl diisocyanate (DDI) and its application in PBX were studied. Results show that when the molar ratio of isocyanate group (NCO) in the mixture of DDI/IPDI is 1/3,the tensile strength and elongation of HTPB-based polyurethane reach the maximum value of 0.427 MPa and 579.9%. When the molar ratio of NCO in DDI and IPDI is 1/1,the compressive failure load of polyurethane reaches the maximum. The elongation of HTPB-based polyurethane cured by DDI/IPDI is 2.51 times greater than that of HTPB-based polyurethane cured by toluene diisocyanate (TDI). In comparison with the compression ratio of HTPB-based polyurethane cured by TDI,the compression ratio of HTPB-based polyurethane cured by DDI/IPDI increases by 57.3%. The critical response threshold of impact sensitivity test and shear test for PBX tablets cured by DDI/IPDI increases more than 0.25 m,indicating that the impact safety of PBX is improved.

Abstract:To study the effect of loading ratio of thermobaric charge on the damage power of warhead,the experimental study on formation products and energy output characteristics after explosion of 30 kg thermobaric charge composed of 65% HMX and 35% high activity grading Al powder as main components was carried out. According to test results,the mathematical calculation model of characterizing the total energy and total specific impulse of thermobaric warhead damage power was set up. With the help of results obtained by static explosive test from the ground 1.5 m of a 200 kg thermobaric warhead with 70 kg thermobaric charge,the overpressure and specific impulse of shock wave at different distance to the explosion center were calculated using the obtained mathematical model. Results show that the calculated and the experimental results have good consistency,which proves correctness of the mathematical model. The changes in total specific impulse at different distance to the explosion center for the 200 kg thermobaric warhead with different loading ratio were calculated,indicating that the specific total impulse and damage power has a maximum value when the loading ratio is 40%.

Abstract:In order to investigate the propagation characteristics of shock wave generated by thermobaric explosive,series experiments with thermobaric explosive of RDX/Al/AP/HTPB and the column mass of 400 g were carried out in an explosion chamber. Pressure histories were obtained by piezoelectric measurement system for the measurement points on the ground and in the air. The explosion process was simulated with AUTODYN software using JWL-Miller equation for detonation products. The parameters of JWL-Miller EOS were calibrated by experimental data. Results show that the error of peak pressure and action time between experiment and simulation are too small to be neglected. The Miller remainder can describe the after-burning features of thermobaric explosive reasonably. The simulated pressure distributions show that both normal reflection and oblique reflection occurred in the explosion chamber. Regular reflection and Mach reflection are two forms of oblique reflection. Normal reflection occurs at the ground projective point of the explosive charge. The peak pressure of reflected wave is 3.3 times higher than that of incident wave. Regular reflection occurs at where the incident angle is less than 40°,and the peak of reflected wave is about 2.5 times higher than that of incident wave. Mach reflection occurred at where the incident angle is more than 40°,and the peak of Mach wave is about 1.2-1.6 times higher than that of incident wave. There are regular reflections at side wall and dome. There is focus phenomenon at geometric symmetry axis. The peak overpressure of shock wave on the focus point is above 2200 kPa,and more than 4.3 times higher than that of incident wave. Reflection and focus of shock wave strengthen the overpressure in chamber.

Abstract:A synchronous explosive circuit with the typical plate structure was put forward with the booster explosive containing 45% RDX,45% HMX and 10% energetic binder. The diameter of explosive particles were smaller than 100 nm. The key structural parameters of this explosive circuit are obtained by test and simulation as notch width 1.2 mm,and parent plate thickness 3.8 mm. The synchronization of the explosive circuit was theoretical analyzed. Results show that the maximum value of the synchronization error of eight output parts are less than 152.2 ns. The experimental verification show that the initiating bursting precision of the explosive circuit is about 170 ns,which meets the requirement of multi-mode warhead forming a good shape penetrator. The live projectile test show that the eight-point synchronous explosive circuit can form a jet warhead with a good shaping and relatively smaller lateral offset,which meets the operational requirement of the shaped charge warhead.

Abstract:To evaluate the environmental adaptability of the pressed RDX-based aluminized explosive(JHL-X),the internal damage,safety and mechanical performance of grain before and after thermal shock of JHL-X were studied by -55-70 ℃ temperature cycle impact test. The safety performance of this explosive was characterized by spontaneous ignition temperature and shock wave sensitivity. The mechanical performance was characterized by elasticity modulus,compression strength and fracture strain. Results show that the main damage of the JHL-X explosive grain interior after the thermal shock is micro-pores and micro-cracks. Its safety property decreases slightly. The spontaneous ignition temperature drops from 211 ℃ to 208 ℃,and the shock wave sensitivity increases from 51.5 mm to 53.5 mm. The elasticity modulus and compression strength increase by 85.3% and 37.7%,respectively,while the fracture strain decreases 29.2%.

Abstract:The interaction and compatibility of N-oxidiation-3,3′-azobis(6-diamino-1,2,4,5-tetrazine) (DAATO_3.5) with main components of modified composite double-base(CMDB)propellant were studied by using differential scanning calorimetry(DSC) and vacuum stability test(VST)method,and the compatibility of DAATO_3.5 with mixture system of CMDB propellant was investigated by curing experiment of propellant at 70 ℃. DSC results show that there are no obvious interaction between DAATO_3.5 with nitrocellulose (NC),nitroglycerine (NG),cyclotetramethylenete-tranitramine (HMX),3,4-dinitrofurazano-furoxan (DNTF),aluminum powder (Al),N-nitrodihydroxyethylaminedinitrate (DINA),carbon black (C.B) and 1,3-dimethyl-1,3-diphenylurea (C₂). There are obvious interaction between DAATO_3.5 with cyclotrimethylene-trinitramine (RDX),hexanitrohexaazaiso -wurtzitane (CL-20) and resorcinol (Res). Res is found no influence on peak temperature but can obviously change the peak profile of DAATO_3.5. Ammonium perchlorate (AP) has no interaction with DAATO_3.5,while DAATO_3.5 can remarkably decrease the onset temperature of AP from 310 ℃ to 275 ℃ and make the double decomposition peak of AP merge into one decomposition peak,with the decomposition peak temperature decreasing 52.9 ℃ than the high decomposition peak temperature of AP. VST results show that DAATO_3.5 with AP is compatible,with Res is incompatible and with RDX have moderate reaction. It was experimentally show that DAATO_3.5/CMDB propellant could be safety preparated uniformly and compactly at 70 ℃. It can be concluded that DAATO_3.5 may be applied to CMDB propellant.

Abstract:The cobalt oxide @ carbonized wings nanocomposites (Co₃O₄@CW) were prepared by hydrothermal method. The structure and composition of Co₃O₄@CW were characterized by X-ray diffraction(XRD),field emission scanning electron microscope(FESEM),transmission electron microscope (TEM)and the surface area and pore size analyzer. The thermal decomposition of ammonium perchlorate (AP) in the presence of Co₃O₄@CW was investigated by simultaneous thermal analyzer (DSC-TG). Results show that Co₃O₄@CW nanocomposites possess the hierarchical micro-,meso-and macro-porous structure,and Co₃O₄ nanoparticles load on the skeleton of the carbonized wings in uniform and compact form. In which,the load of Co₃O₄ is about 72.0%. The Co₃O₄@CW can significantly reduce the temperature of the high temperature decomposition peak of AP. When the addition amount of Co₃O₄@CW is 3%,it makes the temperature of the high temperature decomposition peak of AP decrease by 147 ℃ and the apparent heat of decomposition increase from 173.4 kJ·mol^-1 to 369.3 kJ·mol^-1,indicating a good catalytic performance.

Abstract:To reduce the mechanical sensitivity of ultra-fine ammonium perchlorate (AP),a surface modification of ultra-fine AP was performed by jet mill and the ultra-fine AP composite particles,including ultra-fine AP/nano-graphite(AP-1),ultra-fine AP/graphite(AP-2),ultra-fine AP/carbon black(AP-3) and blank ultra-fine AP comparison sample(AP-C),which were prepared using nano-graphite,graphite and carbon black as insensitive modifier. The morphology and structure of the composite particles were characterized by field emission scanning electron microscopy (SEM),micro particle size instrument,X-ray powder diffraction (XRD) and Fourier transform infrared spectrometer (FTIR). The mechanical sensitivity of ultra-fine AP before and after composition was tested by impact sensitivity instrument and friction sensitivity instrument. Thermal decomposition performance of the composite particles was investigated by differential scanning calorimeter (DSC). Results show that compared with the AP-C,the impact sensitivities of AP-1,AP-2 and AP-3 decrease by 18.2%,21.2% and 8.9%,respectively,and the friction sensitivities of AP-1,AP-2 and AP-3 decrease by 12.5%,12.5% and 8.3%,respectively,and the high temperature decomposition peak at a heating rate of 10 ℃·min^-1 of AP-1,AP-2 and AP-3 shifs 75.4,64.2 ℃ and 44.5 ℃ downwards,respectively.

Abstract:The rate and quality of plasticizing for 1,5-diazido-3-nitrazapentane (DIANP) and nitroglycerine (NG) on nitrocellulose (NC) were compared using dynamic rheology and scanning electron microscope technologies. The solubility parameters of DIANP,NG and NC,and diffusion coefficients of DIANP and NG in NC matrix were calculated by molecular dynamics simulations. Meanwhile,the mesoscopic structure of NC/DIANP and NC/ NG blend systems were established by mesoscopic dynamics simulations. Results show that DIANP has a larger diffusion coefficient (2.24×10^-10 m²·s^-1) than that of NG (1.39×10^-10 m²·s^-1) in NC matrix. Compared with NC,DIANP has a better plasticizing quality. The microscopic structures of the two blend systems above are in good agreement with the mesoscopic dynamics simulations results. Besides,the theoretical results of solubility parameters reveal that DIANP and NG have similar intermolecular force,whereas NG has almost the same type of intermolecular force with NC.

Abstract:H₂B₁₀H₁₀ was prepared via an ion exchange reaction using [(C₂H₅)₄N]₂B₁₀H₁₀ as raw material. Six novel heterocyclium decahydrodecaborates,[3-amino-1,2,4-triazolium]₂[closo-B₁₀H₁₀],[4-amino-1,2,4-triazolium]₂[closo-B₁₀H₁₀],[1-H-1,2,3-triazolium]₂[closo-B₁₀H₁₀],[benzotriazolium]₂[closo-B₁₀H₁₀],[1-methylimidazolium]₂[closo-B₁₀H₁₀] and [urotropinium]₂[closo-B₁₀H₁₀] were synthesized by the reaction of H₂B₁₀H₁₀ and the heterocyclic compounds or urotropine. All yields were up to 90%. The structures of the products were characterized by IR,¹H NMR,¹³C NMR and elemental analysis. Thermal properties of six kinds of target compounds were investigated by DSC and TG. The effect of nitrogen heterocyclic cation on the thermal stability of heterocyclium decahydrodecaborates was preliminary discussed. Results show that the decomposed temperatures of six kinds of target compounds are 232.6,274.6,176.1,211.0,219.4 and 164.9 ℃,respectively. The melting temperature of [4-amino-1,2,4-triazolium]₂[B₁₀H₁₀] is 72.8 ℃,which is an energetic ionic liquid with better thermal stability. The stronger alkaline and the higher density of electron cloud for the cationic precursor nitrogen heterocyclic compounds are beneficial to improve the thermal decomposition temperature of the target compounds.

Abstract:Al/CuO Schottky junction transduction chip was designed and prepared based on Schottky barrier theory. The electrical initiation performance of the transduction chip was studied by a breakdown voltage instrument. The electrical explosion characteristics of the chips were studied by a capacitance discharge mode of capacitor discharging circuit. Results show that fot the former,the chips exist an ignition threshold and have the haracteristics of rectification. The breakdown voltage has nothing to do with the number of Schottky junction. The breakdown voltage is 8 V. For the latter,the chips also exist the ignition threshold. The ignition threshold increases with increasing the number of Schottky junction. The chips also have the characteristics of delayed discharge. The delayed discharge time prolongs with increasing the number of schottky junction. At the same time,the chips also have the characteristic of continuous firing when stimulating repeatedly,which revealing that the Al/CuO Schottky junction transduction chip is a novel electrical-explosive device with a nonlinear energy conversion characteristic.

Abstract:Thermal decomposition characteristics of nitroguanidine(NQ) was preliminary studied by differential scanning calorimetry (DSC) dynamic experiment,and the Kissinger and Ozawa method were used to calculate the activation energy of thermal decomposition. The effect of thermal history on the thermal stabilities of NQ was investigated by "interruption and re-scanning" method,and the conclusion was verified with the isothermal DSC experiment. The adiabatic security of NQ was investigated by the adiabatic calorimeter (ARC),and the initial decomposition temperature and heating rate were obtained. Results show that NQ is an energetic material decomposing with melting,and the thermal decomposition is autocatalytic reaction. Thermal history significantly influences the thermal stability of NQ,decreasing the initial thermal decomposition temperature and the peak temperature and increasing thermal decomposition rate at solid state. The initial thermal decomposition temperatures are 213.8-249.9 ℃,whereas the peak temperatures are 215.0-255.2 ℃ at heating rates of 2,5,10 ℃·min^-1 and 20 ℃·min^-1 by dynamic DSC analysis. The apparent activation energy is 111.6 kJ·mol^-1 and 114.2 kJ·mol^-1. The initial decomposition temperature is 170.6 ℃ and the maximum heating rate is 1.414 ℃·min^-1 for adiabatic experiment.

Abstract:The electrochemical reaction behaviors of phenol on Ti/IrO₂-Ta₂O₅ electrode were investigated by cyclic voltammetry. The efficiency of the electrode degradation of phenol was explored by a combination of high performance liquid chromatography (HPLC),total organic carbon (TOC) detector and chemical oxygen demand (COD) digestion device. Results show that the electrochemical reaction of phenol on Ti/IrO₂-Ta₂O₅ electrode mainly occurs in the oxygen evolution reaction zone,whereas a small amount of irreversible direct electrochemical oxidation reaction happens at higher concentration of phenol. The larger oxidation peak current and higher charge efficiency are obtained when the concentration of support electrolyte is 5 g·L^-1 and the initial concentration of phenol is 100 mg·L^-1. Under the suitable operating conditions of initial phenol concentration of 100 mg·L^-1,electrolyte concentration of 5 g·L^-1,reaction time of 120 min and current of 40 mA,the removal rate of phenol,COD,TOC and average current efficiency (ACE) can reach 82%,49%,39% and 24.5%,respectively.

Abstract:HMX/F₂₆₀₂ core-shell composite microspheres were prepared via coat of F₂₆₀₂ on HMX particle surface using the suspension spray drying method,and HMX/F₂₆₀₂ composite microspheres were prepared by the blended solution spray drying method. The effects of the suspension spray drying technological conditions including the inlet temperature,feed rate and solution concentration on the particle size of HMX/F₂₆₀₂ core-shell composite microspheres were investigated. The particle morphology,particle size and impact sensitivity of two samples were characterized by scanning electron microscopy (SEM),laser particle size analyzer and impact sensitivity test. Results show that the optimal conditions of suspension spray drying method are the inlet temperature of 85 ℃,the feed rate of 3 mL·min^-1 and the solution concentration of 2%. The HMX/F₂₆₀₂ composite microspheres have internal defects. and its median particle size is 4.75μm. The morphology of HMX/F₂₆₀₂ core-shell composite microspheres is solid sphere with median particle size of 1.23 μm. The drop height of impact sensitivity for HMX/F₂₆₀₂ composite microspheres and HMX/F₂₆₀₂ core-shell composite microspheres is 31.23 cm and 41.37 cm,respectively,revealing that the HMX/F₂₆₀₂ core-shell composite microspheres have better properties.

Abstract:In order to accurately measure the change in Lagrange particle velocity with time in the shock initiation process of HMX-based PBX, Al-based electromagnetic particle velocity gauge technique was used to measure the change in Lagrange particle velocity with time history in HMX-based PBX samples under the incident shock wave pressure of 3.07, 4.14, 7.81 GPa and 8.12 GPa. Results show that the time response of Al-based electromagnetic particle velocity gauge is very fast and the rising-up time of impact response for induction unit is less than 20 ns. The time response for the change in Lagrange particle velocity with time at 1-8 mm depth position of HMX-based PBX obtained under different incident shock wave pressures obtained is fast and the interference is small.

Abstract:The progress on the methods of improving the interfacial bonding for TATB-based polymer bonded explosive(PBX) in recent years was reviewed. The selection principle for an appropriate binder and how to effectively evaluate the interfacial bonding from the point of TATB molecular structure, as well as the molecular simulation of the interface interaction between TATB and fluoropolymer were summarized. Meanwhile the effect of the surface modification of TATB and coupling agents on the interfacial bonding were mainly described. At last, three key research directions are stated: the structural design of binder, the addition of coupling agents and the new coating method.

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