Abstract:Accurate acquisition of dynamic pressure waveform for detonator output is the basic guarantee to well and truly estimate detonator output power. Based on the analysis for the output pressure waveforms of detonator-type detonation elements by means of manganin piezoresistance,the influences of different factors,such as sensor protective media,detonator bottom capsule shapes and fragments,on the output waveforms are explained. The investigations showed that a right full detonator output pressure waveform should consist of a steep pressure rise front and a tensile signal after the front. The period of a rise front is 10 ns. When a thinner Mylar film is used as protective medium,the pressure rise front will quickly fall to zero before reaching its peak. The protective medium using 1 mm thick PMMA film is better than that of 0.1 mm Mylar film. The pressure rise fronts of concave bottom and no bottom capsule detonators are much less steep than that of flat bottom detonator and there is a persistent period of pressure flat after their peaks. Besides,the possible bad effects from experimental system on the pressure waveform are also discussed.

Abstract:By experiments of emulsification stability and observation of microscope photographs,effects of two kinds of emulsifier polyvinylpyrrolidone and lecithin on dispersion of wax in composition B were studied. It is concluded that polyvinylpyrrolidone can decrease surface tension of wax effectively and disperse wax in melting composition B in small wax drop,but make color of the system darken. While adding lecithin in the system,change of the color isn′t obvious,but stability time of the system is shorter. However,the mixture composed of lecithin and NC is a good complex emulsifier for dispersing wax in composition B and doesn′t result in color change of the system. The differences between microstructures without emulsifier,with single emulsifier and with complex emulsifier are given in this paper.

Abstract:RDX dust detonation in suspension behind shock waves was analyzed with two-phase flow model. In the two-phase flow model,steady-state detonation regimes were studied on the basis of the mathematical model of detonation of RDX particles taking into account differences in velocities and temperatures of the mixture components. In this paper,pressure of detonation and development of temperature were numerically simulated when concentration of particle changed. Distribution of parameter was obtained and detonation of RDX dust-air in suspension didn′t arise if the concentration of particles was less than 0.076 kg·m^-3.

Abstract:On the basis of analyzing expanded mechanism of expansible graphite,attenuation performance of expanded graphite in three-dimensional space at 3 mm and 8 mm wave was studied by experiments. The results show that expanded graphite has a valuable attenuation performance at 3 mm and 8 mm wave,and its attenuation performance decreases with the reduction of expansible graphite particle size. It is essential to choose appropriate particle size to obtain a valuable attenuation performance when expansible graphite is used as a new millimeter wave interfering material or the main component of smoke composition.

Abstract:Dendrimer bonding agent (DBA) was applied in PET systems under the existence of solid filler(HMX,RDX and AP) to form test pieces. The mechanical properties of these test pieces were detected so as to study the bonding function of DBA. Excellent mechanical properties of propellant test pieces were obtained by adding 0.4% DBA. It was found that ester group could improve the max drawing intensity effectively while nitril group can improve the drawing rate. Also,stress-strain curves were analyzed to further investigate the interfacial binding property of test pieces.

Abstract:To investigate the thermal decomposition behavior of ［Cd(CHZ)₃］(ClO₄)₂ (CdCP),the T-jump/FT-IR spectroscopy was used to determine the main gaseous products evolved from the thermolysis of CdCP in real time. CdCP was flash-pyrolyzed at 200 ℃·s^-1 to the set temperature under different pressures. With the help of rapid scanning Fourier transform infrared FT-IR spectroscopy,11 IR-active gas products were resolved during the flash pyrolysis process. The change curves of the concentration of the main gaseous products vs. time were given,indicating that over the range of pressure from 1.0 to 15 atm,the thermal decomposition behavior of CdCP does not seem to be obviously affected by the pressure.

Abstract:The reaction kinetics of synthesis of tetraacetylhexaazaisowurtzitane (TAIW) by hydrogenolysis debenzylation of tetraacetyldibenzylhexaazaisowurtzitane (TADB) was investigated,using Pd/C as catalyst in an atmosphere of hydrogen. Results show that the reaction is the first-order to TADB during the stage from the beginning to the moment when about 90% H₂ is absorbed under the experimental conditions. When the solvent is acetic acid mixture,the apparent activation energy and pre-exponential factor of this reaction are 45.63 kJ·mol^-1 and 10^6.04 min^-1,respectively. While for acetic acid,they are 79.90 kJ·mol^-1 and 10^9.93 min^-1,respectively.

Abstract:Tetraacetyldinitrohexaazaisowurtzitane (TADN),an intermediate in the preparation of CL-20,has been synthesized readily via the nitration of tetraacetylhexaazaisowurtzitane with HNO₃/AC₂O mixture. The TADN′s structure was determined by X-ray diffraction technique. Its crystal belongs to monoclinic,system and has space group P2₁/n with parameters: a＝1.12231(8) nm,b=1.41083(10) nm,c=1.12331(8) nm,Z=4,V=1.7395(2) nm³,d_c=1.628 g·cm^-3,β=102.039(2)°. The length of C(5)—C(6) bond is 0.1586 nm,a bit longer than that of normal sp³ C—C bond and shorter than the corresponding bond in CL-20. This is due to the fact that,in comparison with CL-20,the electron withdrawing effects of acetyl groups positioned in the two five-membered rings of TADN are weaker.

Abstract:The initial temperature and the maximum peak temperature of the exothermic decomposition reaction of grade two and three coal mine permissible emulsion explosives at different heating rates are tested by differential scanning calorimetry (DSC) . The kinetics parameters of the reaction for emulsion explosives are calculated by Kissinger′s method. With the help of these parameters,the rate constants of the reaction at 120 ℃,150 ℃,250 ℃ are obtained,indicating that with increasing the amount of KCl and NaCl in emulsion explosives,the thermal stability of emulsion explosives increases. Some potential danger in the process are analyzed and some problems on safety in the process of emulsion explosives are presented.

Abstract:The reliability of a cartridge of ejector is estimated by hierarchical Bayes reliability estimation method,based on whole cartridge of ejector test data and its unit test data. The reliability of the cartridge of ejector is reach 0.996 and the estimation result shows the method is effective and the required test number is less than that by attributes method in GJB376.

Abstract:The crushing of HMX was studied by impinge technology. The results show that the particle size of HMX decreased as the impinge pressure and impinge times increased. To some extent it changed very slowly.

Abstract:Absorbed by solvent,butanone-toluene mixture was analyzed by gas chromatography(GC). The absorbent could absorb two substances at the same time. This method has higher linearity and precision,and actual sampling meets the practical demands. Furthermore,the selecting absorbent for butanone-toluene mixture was discussed. The selection conditions for absorbent were given. Results showed that the n-hexanol was the proper absorbent for butanone-toluene mixture.

Abstract:The properties of 1,3,3-trinitroazetidine(TNAZ) (physic-chemistry,thermal stability,eutectic,detonation,crystal and safety properties) are reviewed,the latest progresses on the military (such as gun propellants,melt cast explosives,and propellants)and civil (suah as inflating airbags and fire-extinguishing devices)applications in recent years of TNAZ are introduced in detail. It is consisted that the properties of TNAZ are superior,and TNAZ is one of the most prosperous high energy density materials currently. And the suggestions are also proposed for future studies of TNAZ.

Abstract:Pyrotechnic gas generator is widely used for various airbag systems and lifesaving equipment. Coolant needs to be appended in the gas generator to absorb heat which was given out by combustion of gas generating agent,thereby it reduces the temperature of gas. In this paper,the choice of physical coolant and chemical coolant for pyrotechnic gas generator,cooling methods,the configuration design of cooling cell and numerical simulation of cooling course are reviewed.

Abstract:The process and coating mechanism of boron particles with titanium,zirconium,magnesium,GAP,AP,etc. were introduced. The effect of coated boron on the technology and combustion properties of boron-based propellant was discussed. The results showed that coating is the suitable way to improve the performance of boron-based propellant.

Abstract:The influence of aluminum powder on explosion heat,metal accelerating ability,overpressure and impulse,and DDT (delflagration to detonation transition) properties is reviewed.

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