Abstract:In the HTPB/Boron simple system and the HTPB propellant composed of total solid loading 70～75wt% containing modified boron powder B_S 40～35wt%，the effects of modified boron and the processing characteristics of propellant filled boron powder B_S were studied by means of yield value and apparent viscosity measured with HAAKE RV20 M5/SV2LF and M5/SV2 systems. The results show that according to the processing stability，BS is the best one of all the modified products including B_D、B_W、B_T and B_S. The propellants filled B_S exhibit a good castability,flow level and long potlife，and after mixing 2~3 h the slurry can be described with Casson or Bingham model，when shear up and down to stationary it exhibited obvious shear-thining and constraction recovery respectively.

Abstract:UHF-SCF-PM3 MO method has been employed to study the pyrolysis initiation reaction of tetranitrotetraazabicyclooctane in gas phase. All transition states,activation energies and potential curves of three possible reaction paths are obtained. The changes of the bond orders,geometries and atomic charges over the reaction are revealed. It is found that the homolysis of N—NO₂ bond into two radicals is the initial step of titled compound,which is similar to that of usual nitramine explosives. Finally,the thermodynamic and kinetic parameters have been investigated based on the statistical thermodynamics and transition state theory.

Abstract:A compressive experiment of in situ of SEM was employed to study the heterogeneous mechanical failure behaviors of plastic bonded explosive containing TATB at mesoscale. Digital pictures of Specimen subjected to quasistatic compressive load were captured for calculating deformation fields and displacement vector fields by the help of digital image correlation algorithm. The vortex field of vectors around the tip of preset crack is observed and the final failure model of specimen obeys the axial splitting which shows the difference from the traditionally accepted point of shearing failure. The localization of damage is visualized via distribution patterns of deformation field and displacement vector field which are affected strongly by the pre-exit crack.

Abstract:The thermal decomposition of hexanitrohexaazaisowurtzitane (HNIW) was studied by In-situ FTIR spectroscopy. The spectra of condensed-phase reactant and its decomposition products were recorded from room temperature to 450 ℃. The absorption bands of the condensed-phase decomposition products were assigned. The results of the subtraction FTIR spectra show that a nitro group on six-membered ring homolyzes in the range of the crystal transformation temparature 110 ℃ to 150 ℃. This homolysis causes a series of cleavage reactions to form compounds contained α,β-unsaturated aldehyde and α,β-unsaturated nitroso-group. Above 155 ℃, a nitro group on five-membered ring begins to homolyze and form five-membered ring lactam. Above 165 ℃, more cleavage reactions and self-oxidations occur. Above 190 ℃,oxidation reactions between product molecules dominantly happens besides self-oxidations. A lot of decomposition products are formed,such as dioxoimidazole,dioxopiperazine,acid anhydride,cyanuric acid,ammonium,four,five and six-membered ring lactam etc. Carbodiimide appeared in residues at temperatures higher than 300 ℃ is attributed to the decomposition of amine compounds. Above 400 ℃,chief components in the residue are melem and its polymers such as melon etc.

Abstract:The properties of some bisfurazan ring energetic compounds,such as 5,5′-di(azidomethyl)-3,3′-bis(isofurazan)(DABIF),N,N′-bis(nitrofurazan)oxilicamide(DNFOA),3,3′-dinitro-4,4′-oxazafurazan(DNOAF)and so on,were investigated. The results showed that DABIF and DNFOA were insensitive explosives with H₅₀ (68±3) cm and 82 cm respectively (5 kg hammer). The detonation performance of DNFOA(D=8560 m·s^-1,p_CJ=33.6 GPa) was computed as well as RDX,and DNOAF has excellent detonation performance (D=9390 m·s^-1,p_CJ=40.5 GPa) . Using 20％ of DNOAF as energetic component, the energy pulse(I_sp) of certain NEPE propellant was computed to be 269.1 s^-1,which is higher than 268.6 s^-1 of I_sp of HMX-base NEPE propellant.

Abstract:The conservation of GO，NO-GO Method in GJB 376-87 "Assessment Method of Reliability for Initiating Devices" and the Bayes method of reliability for initiating devices were discussed in the paper. A new GO，NO-GO Method was designed to estimate reliability of initiating devices with less sample-amount. It was deduced using statistical theory and mathematical methods. The Bayes, the new proposed and classical estimation methods were compared experimentally. The results show that the former two exhibit better reliability estimation for initiating devices than the classical estimation, and the new method requires less sample-amount than the other two.

Abstract:Retardation of flaming of anatase titanium dioxide in triethylene glycol dinitrate (TEGDN) propellant is studied by the methods of DTA and Closed Bomb Vessel. Results show that TEGDN propellant containing titanium dioxide has endothermic effect caused by crystal type transformation nearby 900 ℃ in DTA experiment,and its burning-velocity falls very obviously in burning experiment at constant volume. X-ray diffraction graphs testify that crystal type of titanium dioxide has changed from anatase to rutile. It can be concluded that there are flame-retardant factors in burning process of TEGDN propellant containing titanium dioxide: titanium dioxide endothermic effect caused by crystal type transformation and surface-covering effect of titanium dioxide particles in TEGDN propellant. It can be utilized to control the burning-laws of propellants,and achieve the purpose of low temperature sensitivity.

Abstract:Aiming at the particularity of high vacuum and the applicability of the anti-IR smoke in outer space, the NIR attenuation performance of pyrotechnic anti-IR smoke was studied under different vacuums. Experiment results show that the smoke transmittance increases with the increasing of vacuum from 0.10 MPa to 0.04 MPa,and the increase amplitude between the near vacuum intervals is approximately equal. Analysis results show that the increasing vacuum,decreasing smoke mass concentration make the smoke NIR attenuation performance reduced.

Abstract:The mass extinction coefficient of smoke particles is an intrinsic physical parameter to character shielding property. Infrared absorbency of aerosol particles is measured by Fourier transform infrared spectrometer in this article. On basis of quantitative analysis,a kind of method is proposed to rapidly and accurately measure the attenuation property of particles without smoke box in laboratory. Certain mass powder is dispersed in organic solvent,and then suspended solution is scanned by FTIR. According to spectrograms,the extinction coefficients of materials are calculated at infrared frequency. Obtained results are accorded with data measured by smoke box. Consequently,it is proved that above-mentioned experiment method is exactly and reliable. This testing technology can be used to quickly choose and identify shielding effects of new aerosol materials. To traditional test method,it is supplementary and auxiliary.

Abstract:The thermal stability of TEX and its mixtures respectively with HMX and RDX was characterized by VST，Bourdon type glass manometer test and critical temperature determination,and their theoretical half lives were calculated. The results show that TEX has a good thermal stability , and RDX and HMX have little influence on the thermal stability of TEX. Both of them have good compatibility with TEX.

Abstract:The thermal stability of a new plastic bonded explosive PBX-HKF composed of main explosives (HMX and potassium picrate), plasticizer and binder, has been studied by an accelerating rate calorimeter. The curves of thermal decomposition temperature and pressure versus time，self-heating rate and pressure versus temperature were obtained. According to adiabatic theory, the activation energy E_a=337.32 kJ·mol^-1 and pre-exponential factor　9.32E34 s^－1 are obtained. The decomposition history and safety of PBX-HKF were analysed. It is indicated that the new plastic bonded explosive possesses very good.

Abstract:7-amino-6-nitrobenzodifuroxan (ANBDF) was synthesized through three reactions from starting material 3,5-dinitrobenzoic acid with high yield. ANBDF molecule contains one amino-group, one nitro-group and two benzofuroxan rings that are on the benzene ring and are on the same plane. This particular structure characterizes its high thermal stability. The results of TGA and DSC show that ANBDF is an excellent explosive with high thermal stability.

Abstract:The characteristic emission spectra of pyrotechnic composites containing zirconium and magnesium were recorded by a spectrograph. The difference of flame emission spectrum and effects of zirconium and magnesium on visible light and near infrared sections of spectrum were analyzed. The results show that the spectral intensity of visible spectrum is higher for Mg base composite, but the spectral intensity of near infrared spectrum is stronger for Zr base composite.

Abstract:A simple plane-wave lens, using lead wave shaper and nitromethane donor explosive, has been designed. The arrival time deviation of wave front of plane-wave lens is controled by adjusting the height of initial explosion point. The experimental results show that the arrival time deviation of wave front of plane-wave lens designed in this subject is less than 20 ns within 50 mm diameter and have good symmetry.

Abstract:The development of crystal transition technology for HNIW in the last five years is reviewed, including the modified procedures in the laboratories and the industrial process for HNIW′s crystal transitions. The solvents, non-solvents, modifiers and the detailed technological conditions for HNIW′s crystal transition are all described. The effects of various technological parameters on crystal quality are discussed.

Abstract:The principle of small-angle scattering technique to characterize energetic materials′ structure was analyzed in detail. The application of SAS technique used in energetic materials structure′s measuring was also summarized. The research indicated that SAS technique can be used to measure not only the special microstructure of explosives′ powder, but also the explosives pillar and PBX′s microstructure quantificationally. It is also very useful for characterizing ultrafine and nanometer energetic materials′ agglomerating state.

Abstract:The basic principle of VNS (Vicarious Nucleophilic Substitution of Hydrogen) is introduced. Progress in synthesis of TATB,DADNB,DATB,DATNT,CL-14,LLM-116,LLM-119 by VNS amination are reviewed. The prospect of VNS amination in synthesizing explosives is discussed. A number of VNS amination routes for preparing TATB are discussed,analyzed and compared in detail. Conversion of picramide to TATB using hydroxylamine as the VNS aminating reagent is probably the cheapest way. LLNL has achieved an excellent results with high yield,high purity,higher reactant concentrations, petter product appearance without halide contamination in TATB using ATA as the VNS aminating reagent.

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