Aiming at the mechanism, regularity characterization, influence factors and inhibition of ingredient migration in propellants, gun propellants and explosives, the ingredient migration theories which are mainly driven by concentration gradient and polarity action were introduced. The characterization methods of migration ingredients amount and migration ability based on advanced analytical techniques and migration kinetics were summarized. The effects of temperature, intermolecular interactions, crosslinking density, steric hindrance, structure, and other factors on ingredient migration were elaborated. The migration inhibition methods including chemical synthesis, material modification, and additive methods were discussed. The development directions of establishing rapid and non-destructive characterization methods of ingredient migration, improving migration models and synthesizing new ingredients with high anti-migration performance were proposed.Attached with 79 references.

In view of the application defects caused by physical and chemical surface properties of nano-aluminum powder in the field of energetic materials, the controllable preparation methods, protection reactivity methods, and the changes in thermal and energy performance of nano-aluminum powder before and after protection were reviewed. The advantages and disadvantages of typical preparation methods and coating methods were compared, and the influence of coating layer on the thermal reactivity of modified system was analyzed. On this basis, the future development direction of nano-aluminum powder was put forward: developing methods to improve the dispersion of nano-aluminum powder in composite energetic materials; exploring the influence of the interfacial surface bonding method between the coating material and nano aluminum powder on the properties of the system; further application researching of modified nano aluminum powder. Future research should further concentrate on exploring the environmental compatibility of modified nano-aluminum powder to enhance its performance under complex conditions. 66 References are attached.

In order to study the effect of probe structure on the microwave ignition performance, four probes were used to test the microwave ignition delay time of Ti/CuO ignition powder and the probe structure was optimized by simulation. The influence of the probe parameters(length, coating thickness, tip taper, and coating thickness)on the electric field intensity was obtained. The results show that the electric field intensity of the probe tip significantly affects the ignition delay time. Under 2.45GHz and 50W microwave, the maximum electric fields of the four probe tip are 1800, 190, 34, and 53kV/m, respectively. The ignition delay time of Ti/CuO are 222.6, 660.5, 949.1, and 921.3ms, respectively. When the probe length is 26mm, under 2.45GHz and 50W microwave,the PTFE dielectric layer length is 8mm and the thickness is 0.75mm, the tip taper is 0.243 and the gold coating thickness is 5μm, the electric field intensity can be increased from the original of about 10kV/m to about 1000kV/m and the electric field distribution is concentrated at the tip.

From the perspectives of reducing the influence of external stimuli and optimizing the structural design of energetic materials, the desensitization mechanisms of single compound energetic materials under different desensitization strategies are reviewed, including buffering, lubrication, conduction, heat absorption and insulation, improving the quality of energetic crystals and enhancing the stability of energetic molecules. The comprehensive desensitization mechanisms of multi-dimensional desensitization strategies such as using multifunctional desensitization materials and coupling various desensitization means are analyzed. The development directions of desensitization of energetic materials in the future are put forward: to develop energetic materials with both high-energy and insensitive characteristics, to research the relationship between desensitization mechanism of energetic materials and operational environment, and to build up universal quantitative description models of sensitivity from the molecular scale, providing theoretical guidance and technical support for designing new high-energy insensitive energetic materials. 93 References were attached.

Aiming at the pyrolysis and combustion process of the near burning surface of the pasty propellant, the laser ignition combustion experiment of the pasty propellant were carried out. At the same time, the pyrolysis and combustion characteristics of the near burning surface region of the pasty propellant were studied based on the multiphase chemical reaction numerical solver developed by the research group and the 14-component and 14-primitive chemical reaction equation. The macroscopic structure of propellant combustion flame was obtained through experiments and the burning rate of the pasty propellant was measured under constant pressure conditions. The combustion flame structure and chemical reaction sequence of the pasty propellant under constant pressure conditions were analyzed by numerical calculations. The effects of different ambient pressure on the combustion process of the pasty propellant were calculated. The results show that the fitted burning rate curve was in good agreement with the experimental results. In the range of experimental pressure, the burning rate of propellant in the combustion chamber of pasty rocket engine could be predicted well. The decomposition of AP is the first reaction in the combustion of pasty propellant, and the higher ambient pressure limited the diffusion of primary combustion gases, but enhanced the thermal feedback effect on the pasty domain, which increased the burning rate of the pasty propellant.

In order to obtain the optimal casting process parameters of HTPB composite solid propellant, the constitutive model for the flow process of propellant slurry was established based on the rheological properties of HTPB propellant slurry adopting a combination of experimental and theoretical simulation methods. The casting process of HTPB composite propellant slurry was simulated by using the finite element software, and the reliability of the simulation results was verified through experiments. Moreover, the casting process of the propellant slurry was optimized and the optimal casting process parameters were obtained. The results show that HTPB propellant is a typical pseudoplastic fluid, and its viscosity decreases with increasing shear rate. The porosity and the casting time are 12.5% and 11.25%, respectively after comparison of experiment and simulation. Among them, temperature has the most significant impact on casting time, and vacuum degree has the most significant impact on porosity.

Imidazolium 2,4,5-trinitroimidazole was synthesized by nitration of 2,4,5-trinitroimidazole(2,4,5-TII)in different mass fractions(20%, 50%, 65% and 98%)of nitric acid using micro-channel reaction technology, respectively. The structure was characterized by fourier transform infrared spectroscopy(FT-IR), nuclear magnetic resonance spectroscopy(NMR), elemental analysis(EA)and melting point testing. Results show that by using micro-channel nitration reaction technology, the optimal process conditions for preparing imidazolium 2,4,5-trinitroimidazole from 2,4,5-TII are as follows: the molar ratio of 2,4,5-TII and fuming nitric acid is 1:20, the reaction time is 6 min, the reaction temperature is 70～72℃, and the yield is 21.8%. Compared with the conventional tank reactor process, the micro-channel reaction process has the advantages of shorter reaction time, lower dosage of nitration reagent, slightly lower reaction temperature and slightly higher yield. However, it can not completely avoid the occurrence of side-reaction of oxidation.

To enhance the energy characteristics and combustion performance of energetic microchips for their application in micro-propulsors, micro-actuators, and micro-detonators, the ECP@Al@CL-20 energetic array were synthesized through in situ growth of energetic coordination polymer(ECP)on copper foil, e-beam deposition of n-Al, and recrystallization of CL-20. The morphology, phase composition, thermal decomposition, combustion performance, and storage life were characterized by SEM, XRD, TG-DSC and high-speed photography. In addition, the functional ECP@Al@CL-20 energetic microchips were integrated with microelectro mechanical system(MEMS)and subjected to capacitor ignition tests. The results show that the ECP@Al@CL-20 energetic array reduces heat transfer efficiency from outside to inside due to the low thermal conductivity of ECP, resulting an increase of 8.5℃ in the exothermic peak temperature compared to pure CL-20, thereby increasing the thermal stability of ECP@Al@CL-20. The ECP@Al@CL-20 energetic array has excellent combustion performance, its self-sustaining combustion time(340ms)is much higher than that of ECP@Al(120ms), and it can be ignited under 15mJ of input energy.

To study the explosiveness of biomass fuels, TG-DTG thermogravimetric analysis was used to analyze the combustion performance and kinetic parameters of several common biomass fuels(straw, sawdust, peanut shells)and their mixtures. The microstructures of these fuels were analyzed using scanning electron microscopy(SEM). Additionally, an elemental analysis of the wood powder and peanut shell powder mixture was carried out using an elemental analyzer. Based on the elemental composition, the amount of oxygen required for its oxidation reaction was calculated, and an explosion test was subsequently conducted. The results showed that the mixed fuel(wood powder and peanut shell powder in a 1:1 mass ratio)exhibited high stable combustion characteristics, flammability index, and overall combustion performance. The activation energy was moderate, and the surface appeared porous and rough, with more free surfaces and a larger specific surface area, which facilitated combustion. In an experiment,40g of this mixed fuel was loaded into a steel pipe with a diameter of 40mm, a length of 200mm, and a wall thickness of 1.5mm, and filled with 5MPa oxygen. The mixture was successfully detonated by a No.8 electronic detonator without producing toxic gases. The steel pipe was blasted into fragments of different sizes, with most fragments measuring less than 50mm. The research results indicate that biomass fuel can exhibit explosiveness under certain conditions.

To study the characteristic parameters during the plasticization process of propellants, plasticization-extrusion experiments were performed using a twin-screw extruder. The paper aimed to investigate the influence of different solvents, types of plasticizers, and plasticization time on the plasticization of single-base propellants. The Owens three-liquid method was employed to calculate the surface tension of nitrocellulose(NC)after plasticization with various solvents, including ethyl acetate(EAC), tetrahydrofuran(THF), acetone(ACE), and a 1:1 mixed solvent of alcohol and ACE. Further analysis was conducted to assess the impact of different plasticizers on surface tension. The results indicated that the highest surface tension of NC(43.07mN/m)was observed after 90 minutes of plasticization with the mixed alcohol and acetone solvent, which proved to be the most suitable in this study as it prevented sticking to the walls and screws. The surface tension of NC with varying nitrogen contents(12.14%, 12.80%, and 13.45%)was calculated over different plasticizing times using the contact angle method. For all nitrogen content levels, the maximum surface tension values were recorded at 90 minutes of plasticization. The tensile test revealed that at 90 minutes of plasticization, the single-base propellant with 12.80% NC exhibited a maximum tensile strength of 39.10MPa and an elongation at break of 16.9%, aligning empirical method for determining optimal plasticization. In addition, the maximum surface tension occurred earlier at 60 minutes as the plasticizer content increased for NC with nitrogen content of 12.14% and 12.80%; while the maximum surface tension still appeared at 90 minutes for 13.45% NC. The tensile strength and elongation at the break for each group displayed trends consistent with the change in surface tension. The surface tensions were influenced by the solvent, plasticizer, and plasticization time. The trends in surface tension aligned with the tensile properties, making surface tension a valuable preliminary indicator for assessing the plasticizing effect of propellants.

In order to improve the safety performance of HMX, HMX/FOX-7 nano-cocrystals with different molar ratios were prepared by the ultra-low-temperature-assisted recrystallization method, where FOX-7 with low sensitivity was used as another component of the binary cocrystal. The morphology, structure, and thermal properties of the prepared HMX/FOX-7 cocrystals were characterized by SEM, XRD, FT-IR and DSC-TG, and their mechanical sensitivities were analyzed. The results show that the prepared HMX/FOX-7 crystals are mainly porous structure stacked with spherical particles, and their particle sizes are distributed primarily in the range of 0.1—0.5μm. During the formation of HMX/FOX-7 nano-cocrystals, the “low-temperature freezing” of the HMX/FOX-7 solution from liquid nitrogen and the formation of hydrogen bonding among HMX and FOX-7 have an significant influence on the formation of HMX/FOX-7 nano-cocrystals. The apparent thermal decomposition enthalpies of HMX/FOX-7 nanocrystals is significantly higher than that of the raw HMX and FOX-7, and increases with the increase of HMX content. The mechanical sensitivity of each HMX/FOX-7 nano-cocrystal is substantially reduced compared with that of the raw HMX. When the molar ratio of HMX and FOX-7 is 1:3, the prepared HMX/FOX-7 cocrystal has the lowest mechanical sensitivity, where the impact sensitivity is higher than 45J and the friction sensitivity is 288N.

The working principles and recent technological advancements of high-speed photography, spectroscopic testing, laser interferometry, and terahertz Doppler wave measurement techniques were introduced. Also, the application of these techniques in the field of explosive detonation testing was discussed. Among them, high-speed photography and laser interferometry are widely used in the measurement of detonation velocity, pressure, and shock initiation. Spectroscopic testing is mainly applied to detonation temperature measurement and detonation product composition analysis, while terahertz Doppler wave measurement is employed for explosive detonation wave measurement. The advantages and disadvantages of optical-electronic testing techniques in detonation performance research and provided an outlook on the future development of detonation performance testing technologies were analyzed. It is concluded that strengthening the study of micro-scale testing technologies for explosives, expanding the application of current optical-electronic testing techniques, and integrating data processing with big data technologies are key areas for future research in explosive detonation performance. 128 References were attached.

Ag/g-C₃N₄ photocatalyst was synthesized using self-made zinc nitrate-containing deep eutectic solvent(nitro-DES)as nitrating agent. Utilizing the Ag/g-C₃N₄ as photocatalyst, dinitroanisole(DNAN)was successfully synthesized from the nitration of anisole under a mild and non-acidic process. The photocatalyst Ag/g-C₃N₄ was characterized using X-ray powder diffraction(XRD), ultraviolet-visible diffuse reflectance spectroscopy(UV-vis DRS), infrared spectroscopy(IR), scanning electron microscopy(SEM), transmission electron microscopy(TEM)and energy-dispersive X-ray spectroscopy(EDX)analysis. The photocatalytic nitration mechanism of dinitroanisole(DNAN)was predicted. Results show that a low-melting, transparent and polar nitro-DES can be formed spontaneously, which is composed of zinc nitrate and choline chloride in equimolar proportions. It can be not only favored for the absorption and propagation of visible-light but also serve as a nitro source in the nitration reaction. The doping of noble metals is observed to remarkably improve the photocatalytic efficiency of C₃N₄. Using xenon lamp to simulate the sunlight irradiation, the conversion of anisole to DNAN is above 90% within a period of 3h at a temperature of 55℃. The inhibition experiments suggest that the mechanism of photo-driven nitration can be involved with the nitroxyl radicals.

In order to study the fracture properties and crack propagation mechanism of solid propellant, the theoretical research and common numerical simulation methods for fracture and crack propagation in solid propellants were introduced. It is pointed out that the extended finite element method(XFEM)and cohesive zone models(CZM)are the most common techniques for fracture simulation of solid propellants. The influencing factors of fracture properties of solid propellant were summarized, and the experimental studies on the interfacial dehumidification mechanism of solid propellants are reviewed. Compared to crack size and loading rate, temperature, ageing and confining pressure can change the crack propagation mechanism of solid propellants. Finally, the research on solid propellant fracture was prospected. It was considered that the research on dynamic fracture considering the influence factors of thermodynamic coupling, fracture performance in combustion environment, real-time microscopic observation of the whole process under dynamic loading and the update of numerical simulation methods will be the focus of the future research on solid propellant fracture and crack propagation with 73 references.

By comparing the differences in the physical and chemical properties, such as the enthalpy of formation and phase transition temperatures of the fluorinated/oxidized products of metal fuels, the characteristics and potential application advantages of fluorination energy release reactions in energetic systems were summarized. The research progress of composite energetic systems based on fluorinated oxidizers, including typical types and characteristics of fluorinated oxidants, as well as their applications in pyrotechnics, propellants, mixed explosives, and aluminum thermites has been reviewed. The research and development direction of the application of fluorine-containing oxidizers in composite energetic systems was prospected. It is pointed out that the systematic computational chemistry research on composite energetic systems based on different fluorine sources should be conducted to understand the thermodynamic and kinetic mechanisms of fluorination reactions and their structure-activity relationships at the atomic/molecular level. Furthermore, research should also be intensified on the fluorine transfer mechanism in combustion reactions and the interfacial fluorine infiltration mechanism under pre-ignition conditions. Based on this, new typical fluorine-containing oxidizers suitable for different scenarios should be developed from the view point of nano architectonics and reaction pathway design. Attached with 137 references.

To explore the preparation process and combustion performance of high active metal energetic microspheres, Al/B/PTFE energetic microspheres were prepared by emulsion self-assembly technology with Viton as binder, polytetrafluoroethylene(PTFE), boron powder(B)and aluminum powder(Al)as high-energy components. The volatilization temperature of solvent, the type of emulsifier, the volume ratio of water phase to oil phase and stirring speed were optimized. The morphology of Al/B/PTFE energetic microspheres was characterized by scanning electron microscopy(SEM). The thermal decomposition properties of Al/B/PTFE energetic microspheres were analyzed by TG-DSC method. The combustion reaction performance of the microspheres was characterized by high-speed photography and closed explosive bomb device. The results show that the optimum preparation process of Al/B/PTFE energetic microspheres is water bath temperature of 25℃, emulsifier of PVA, water-oil volume ratio of 80:30 and stirring speed of 700r/min. The prepared Al/B/PTFE energetic microspheres have uniform particle size, high sphericity and controllable particle size, and the main particle size distribution range is about 300～900μm. The dispersion, reaction heat, combustion flame area and pressure output performance of the microspheres increase first and then decrease with an increase in the particle size. The maximum reaction heat, the maximum flame area, and the maximum peak pressure of Al/B/PTFE energetic microspheres are 1097.97J/g, 186.06cm² and 213.3 kPa, which are 1.77 times, 5.16 times and 1.37 times of the physical mixed samples, respectively.

In order to explore the electrostatic spinning process for the preparation of ETPE-based multicomponent energetic composite fibers, the GAP-ETPE-based ultrafine energetic composite fibers were prepared by electrospinning technique using poly(glycidyl azide ether)thermoplastic elastomer(GAP-ETPE)as the polymer binder and CL-20 and nano aluminum powder(n-Al)as the high-energy components, and the key process parameters such as solvent, mass fraction of precursor and solid phase composition ratio were optimized. The product morphology was characterized by scanning electron microscopy(SEM)and transmission electron microscopy(TEM). The thermal decomposition behavior of the composite fibers were analyzed by DSC method. The mechanical sensitivities of the composite fibers were tested. The results show that the best solvent for the preparation of GAP-ETPE-based energetic composite fiber electrospinning is acetone, where the products are uniform with smooth surface. The binary ultrafine energetic composite fibers(CL_x-ETPE_y-Z)have the best filament formation with an average diameter of about 2480nm when the mass ratio of GAP ETPE/CL-20 is 3:7 and the mass fraction of precursor solution is 50%. When the ternary ultrafine energetic composite fiber of the mass fraction of aluminum powder is 10% and the concentration of precursor solution is 50%, the filament formation is optimal with an average diameter of about 930nm. Compared with CL-20, the peak thermal decomposition temperature of CL₇-ETPE₃-50 energetic composite fiber is advanced by 29℃. Also, the peak thermal decomposition temperature is advanced by 32℃ with the addition of n-Al, which is better than the Physical Co-Mixes(PM). The frictional sensitivities of GAP-ETPE/CL-20 and GAP-ETPE/CL-20/Al energetic composite fibers are 32% and 48%, respectively, and the impact sensitivities are 29cm and 43cm, respectively. Compared with CL-20 sensitivities(P=100%, H₅₀=17cm), the mechanical sensitivites of the two energetic composite fibers are siganificantly decreased. Both the frictional and impact sensitivities are lower than those of the physical blends of the same formulation.

In order to establish the general ignition criteria on solid propellant, the recent domestic and foreign solid propellant ignition criteria were summarized from experiment and simulation analysis aspects, respectively. The ignition criteria for solid propellant at the experimental level include ignition/non-ignition criteria, pressure criteria, temperature criteria, spectral radiation intensity criteria and multi-parameter co-ignition criteria. Comparative analysis shows that the ignition criteria are limited by the experimental conditions and the test equipments, and there are defects such as the key ignition temperature is difficult to be got, and there is a delay in parameters testing, so it is difficult to expand the application.However, the multi-parameter collaborative ignition criterion has higher accuracy and greater promotion possibility. At the simulation level, the temperature ignition criteria, the pressure ignition criteria and the chemical signal ignition criteria are mainly established based on solid phase, gas phase and out-of-phase ignition theories. Compared with the experimental ignition criterion, the simulated ignition criterion is more consistent with the ignition theory of solid propellant, but the key parameters such as ignition temperature and dynamics data obtained from the experiments are required as the model input, and the ignition theory of different types of propellants is different, so the ignition criterion still needs to be further studied. In addition, the correlation and generality of experimental and simulated ignition criteria are discussed. 49 References are attached.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.

Aiming at the problems of nitration reaction such as intense exotherm, large volume online, and serious safety hazards during the synthesis of N-nitromethylamine(NMA), the precursor of linear nitramine energetic plasticizers(DNDAs), micro reaction technology was adopted to carry out the nitration of 1,3-dimethylurea using nitrate-sulfur mixed acid. Critical intermediate NMA was further synthesized through the hydrolysis reaction. The structure of synthesized NMA was characterized, and the reaction conditions of nitration were also optimized. The results show that micro-reaction technology can solve the problems of uncontrollability and high safety risk caused by large amounts of heat release and volume online of nitration reaction in the process of synthesizing NMA. The optimal nitration reaction temperature is 15℃, the optimal material mol ratio of nitric acid, sulfuric acid and 1,3-dimethylurea is 1:0.78:0.67, and the average residence time was 22.5s. The yields of NMA reached 90.7%, and the purity was 99.2%. This micro-reaction process has the advantages of high reaction temperature, high safety, fast reaction rate, and high product yield.

In order to study the dynamic mechanical properties of TiZrNbHf RHEA under dynamic impact, a flat plate impact experiment was carried out by using a 20mm caliber first-stage light gas gun, and the recovered samples were analyzed by scanning electron microscopy on their delamination mechanism from a microscopic perspective. The results show that the delamination strengths of TiZrNbHf RHEA ranges from 1.81 to 2.41GPa when the peak pressure of plastic wave pressure ranges from 0 to 20GPa. The delamination strength of TiZrNbHf RHEA is lower than that of 3d-HEA. The Hugoniot elastic limit ranges from 3.05GPa to 3.57GPa, increases with the increasing of impacting speed, and the reacceleration increases with the increasing of impacting speed. The Hugoniot equation of state obtained by the experiment shows a linear relationship. The state equation obtained by the cold energy mixing method is lower than the test data, but it can be used to predict the materials' properties over the experimental range. The metallographic analysis of the recovered samples shows that the SE and BSE image maps show that the holes are connected to form cracks, there are a large number of dimple and a small number of river-like patterns in the damage area, indicating that the damage mode is a mixed fracture mode dominated by ductile fracture.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.

In order to explore the thermal decomposition and combustion performances of zirconium powder(Zr)with high-energy oxidant composite, the thermal decomposition behavior, combustion heat and ignition combustion process of four kinds of energetic materials(EMs)of AP, CL-20, HMX, DAP-4 and Zr/EMs samples were compared and analyzed by using differential scanning calorimetry, automatic calorimetry and self-built combustion experimental system. Some combustion products were collected and characterized. The combustion mechanism of Zr/DAP-4 was analyzed. Results show that the thermal stability and combustion heat release of DAP-4 are better than that of the other three EMs samples. The addition of Zr leads to a higher combustion heat and a lower E_a value of the sample, the thermal decomposition temperature remains at 373.8℃, and the combustion performance is better than that of pure DAP-4. Compared with the thermal decomposition of Zr/CL-20 and Zr/HMX, Zr/DAP-4 has a higher initial decomposition temperature and peak temperature, a lower apparent activation energy E_a(138.7kJ/mol), and a higher combustion heat(17134J/g). The entire combustion time of Zr/DAP-4 composite is only 170ms, indicating a rapid and intense combustion reaction and its flame intensity is also superior to the other three samples. The combustion products of Zr/DAP-4 include solid products such as ZrO₂ and gas products such as H₂O and HCl. Zr/DAP-4 composite energetic material has higher energy characteristics and better combustion performances, which make it has great potential for application in the formulation design of propellants.

In order to study the effect of arc-cone part of the liner on the performance of explosive shaped projectiles, numerical simulations by ANSYS/LS_DYNA was conducted to calculate concentrated charge model of the ratio of arc-cone angle to the slant height of the liner are 1/7, 2/6, 3/5, 4/4, 5/3, 6/2, 7/1, while controlling other variables to remain the same. A numerical model was established using the simulation software ANSYS/LS-DYNA, and simulations were performed to obtain the corresponding results. The numerical simulation results were then validated through experiments, analyzing parameters such as velocity, length, and compaction of explosion shaped projectiles formed with different arc-cone angle ratios. The results indicate that the velocity of the explosion shaped projectiles decreases gradually with increasing arc-cone angle ratio, stabilizing after the ratio of 3/5. The fracture time of the projectiles also decreases as the arc-cone ratio increases. For ratios between 3/5 and 5/3, the projectiles typically fractured into three parts, while those at the ratio of 6/2 fractured from the middle; the variations among ratios from 3/5 to 7/1 were not significant. By comprehensively comparing parameters such as speed, fracture time, and number of fracture parts, it was found that at the arc-cone ratio of 5/3, the projectile achieved a maximum speed of 2123m/s, with the least number of fractures(3 pieces)and a good level of compaction, resulting in superior overall flight performance and penetration capability. The experimental measurements of the projectile's speed showed a deviation of around 5% from the numerical simulation results, sufficiently validating the reliability of the research findings.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.

In order to study the thermal-mechanical coupling behaviors and mesoscale damage mechanism of HTPB solid propellants under high frequency cavitation impact, a three-dimensional full gradaed HTPB solid propellant mesoscale modeling was proposed considering the actual interface between particle and matrix. Different from the traditional meso-mechanical model in which virtual cohesive force interface element is embedded between particle/matrix interface, the thermo-mechanical coupling meso-mechanical model of solid propellant under the impact of cavitation microjet is further established. The breaking mechanism, damage mechanism, local stress strain and temperature distribution of solid propellant were analyzed. The results show that the AP particles break directly when the cavitating microjet acts on the AP particles. With the increase of impact degree, the interface layer between AP particles and HTPB matrix is fractured by impact. The maximum stress and strain values of solid propellant after cavitation microjet impact are 34.27MPa and 1.314, respectively. The stress wave transmission path change due to the obstruction of AP particles, Al particles, and interface phases. The maximum temperature value of the cavitation impact solid propellant process shows a gradually increasing trend due to the gradual accumulation of fracture energy, internal energy and friction energy. The maximum temperature value is 24.59℃. The solid propellant at a position far away from the cavitation microjet has no obvious temperature rise due to the low heat transfer coefficient.

In order to study the energy release of gallium-based liquid metal(GLM)-Al-fluoropolymers, GLM-Al with GLM mass friction of 1%, 3%, 5%, 7% was prepared, and GLM-Al-fluoropolymer composite reactive materials were obtained by 3D printing. The microstructure, combustion performance and mechanical properties of GLM-Al and GLM-Al-fluoropolymers were tested by SEM, EDS, XRD, XPS, DSC-TG, high-speed video camera and universal tensile test equipments. The results show that the heat release and the oxidation weight increase of GLM-Al modified with 3% GLM is the largest, which is 6181J/g and 42.92%, respectively. Al-fluoropolymers before modification cannot be ignited, but the modified GLM-Al-fluoropolymer can be ignited and can continuour to burn stably, with the maximum burning rate of 6.0mm/s at equivalence ratio of 3.5. and the tensile strength and elongation of GLM-Al-fluoropolymers at break are the largest of 1.73MPa and 11486%, respectively, which are 1.5 times and 1.3 times higher than that of Al-fluoropolymers before modification.

To enhance the safety performance of energetic materials during production and utilization, microfluidics technology was employed to successfully and continuously fabricate high-energy impact-insensitive LLM-105/CL-20 composite materials using modified fluororubber as a binder. The microstructural morphology of the samples was observed using field emission scanning electron microscopy(SEM), while the structure and crystalline phase were analyzed through Fourier-transform infrared spectroscopy(FT-IR)and X-ray diffraction(XRD). The thermal decomposition behavior of the samples was assessed via differential scanning calorimetry(DSC), and the mechanical sensitivity of raw material CL-20 and composite particles was tested. The results show that under optimal conditions-where the solvent-to-nonsolvent flow rate ratio was set at 1:6, the binder mass fraction was 6%, and the total flow rate was 80mL/min-LLM-105 was effectively coated on the surface of CL-20, with particle size distribution ranging from 0.19 to 3.92μm. Characterization by FT-IR and XRD further confirmed the successful coating of LLM-105 on the surface of CL-20. The impact sensitivity of composite particles was increased from 10cm to 55cm(drop mass of 2kg), significantly enhancing their safety performance. The methodology of preparing LLM-105/CL-20 composite particles within microchannels demonstrated advantages in reducing sensitivity, showing that this method is easy to operate and suitable for continuous safe production.

Two types of nano-sized metal oxides(nano CuO and nano Fe₂O₃)were prepared by hydrothermal method, the activated carbon was loaded onto the prepared nano CuO, nano Fe₂O₃ to obtain CuO@C and Fe₂O₃@C composites, and the prepared four types of catalysts were mixed with ammonium perchlorate(AP)to form mixture samples AP/CuO,AP/CuO@C,AP/Fe₂O₃,AP/Fe₂O₃@C. The catalytic mechanism and thermal decomposition kinetics characteristics of four types of catalysts for AP thermal decomposition were carried out through scanning electron microscope(SEM), differential scanning calorimeter(DSC), thermogravimetric-differential thermogravimetric(TG-DTG), and thermogravimetric-infrared spectrum(TG-FTIR)techniques respectively. The results show that the four catalysts catalyze two-step thermal decomposition reaction of AP into a single exothermic peak. At a heating rate of 5K/min, the thermal decomposition peak temperatures of AP were forwarded by 90.1, 73.4, 65.4, and 69℃ than those of pure AP, respectively. The main gas phase thermal decomposition products include HCl, CO₂, N₂O, HNO₃, and NO₂ in AP/CuO@C with the highest content of NO₂. The CO₂ content in the main gas phase thermal decomposition products increases significantly, while the NO₂ content slightly decreases in AP/Fe₂O₃@C.

The influencing factors of fracture properties of solid propellant were summarized, and the research status of fracture properties and crack propagation of solid propellant was reviewed; The common numerical simulation methods for simulating propellant fracture and crack propagation were introduced; The research on solid propellant fracture was prospected. It was considered that the research on dynamic fracture considering the influence factors of thermodynamic coupling, fracture performance in combustion environment, real-time microscopic observation of the whole process under dynamic loading and the update of numerical simulation methods will be the focus of the future research on solid propellant fracture and crack propagation with 75 references.

The micro-reaction technology for the preparation of nitroaromatics, nitrate esters, nitroamines, and other energetic materials are overviewed. The existing preparation processes for these energetic materials by using micro-reaction technology are classified and described. The micro-reaction technology has the advantages of enhancing product yield and selectivity, improving mass and heat transfer efficiency, and reducing reaction time. The issues such as blockages in micro-reaction synthesis are also analyzed. Furthermore, this review explores the application of micro-reaction technology in the preparation of micro and nano energetic materials and composite energetic materials. The benefits of micro-reaction technology in controlling particle size and morphology and continuous preparation of energetic materials are emphasized. By summarizing the existing technical difficulties, it is pointed out that the combination of micro-reaction technology with numerical simulation, the optimal design of reaction and heat transfer structures, and the exploration of reaction mechanisms are the important research fields for the application of micro-reaction technology in the preparation of energetic materials. 80 References are attached.

Based on a simple droplet microfluidic technology to produce a single emulsion, the core-shell microspheres with 4-nitrobenzaldehyde(p-NBA)as nuclear layer and polystyrene(PS)as shell layer were prepared, combined with phase separation and crystallization solidification. The p-NBA was coated in one step as the analog of 3,4-dinitrotrifluorotoluene(DNTF). The microspheres with different structures and morphologies were obtained by adjusting the ratio of p-NBA, PS and the shaping agent ethyl cellulose(EC). The influence of above factors on the structures of core-shell microspheres was studied. Based on the double conditions of coating passivation effect and coating amount of high energy explosive DNTF, the optimal experimental conditions were obtained when using PS with large molecular weight(M_r=300000—350000): the mass ratio of EC and p-NBA is 1:10, and the mass fraction of PS is 8%. The results show that the addition of excipients can promote the crystallization of p-NBA and allow it to form spherical particles when the droplet phase is separated, then it can be completely coated. The larger the initial mass fraction of PS in the microdroplet, the thicker the shell layer and the higher the sphericity. However, the thicker the shell encapsulated with DNTF, the lower the detonation power.

To investigate the process optimizationof Cu-en/AP composite microspheres preparation via electrostatic spraying, and to reveal the effects of droplet properties and flow rate variations on the experimental results during the electrostatic spraying process, the prepared process parameters of Cu-en/AP composite microspheres by electrostatic spray method under the orthogonal experimental design simulated by ANSYS(Fluent). The influence of flow rate, solvent ratio, and solid mass on the experimental results is examined using a controlled variable method. The results indicate that under the conditions of a flow rate of 2.67×10^-3kg/s an acetone-to-deionized water ratio of 1.5:1.0, and a solid mass of 200mg, the theoretical particle size of the composite microspheres can reach e nanoscale. Droplet trajectories in the electric field remain stable without significant deviation. The simulation results show that particle diameter decreases with increasing flow rate, with the trend leveling off around a flow rate of 1×10^-3kg/s. As the solvent ratio increases(with higher acetone content), particle diameter initially decreases, reaching a minimum around a ratio of 1.5:1.0 before gradually increasing. Increasing the solid mass also reduces the particle diameter, with a linear increase in diameter observed at around 220mg. Cu-en/AP composite microspheres with nanoscale dimensions were confirmed under these conditions by the final SEM images.

1-Methyl-2,4,5-trinitroimidazole(MTNI)was synthesized by nitration of 1-methyl-2,4-dinitroimidazole(2,4-MDNI)with nitric-sulfuric mixed acid, and methylation of potassium 2,4,5-trinitroimidazole(2,4,5-TNIK)with dimethyl sulfate(DMS)using micro-channel reaction technology, respectively. The structure was characterized by fourier transform infrared spectroscopy(FT-IR), nuclear magnetic resonance spectroscopy(NMR), elemental analysis(EA)and melting point testing. The results show that by using micro-channel reaction process, the optimal conditions based on nitration of 2,4-MDNI are as follows: the molar ratio of 2,4-MDNI and fuming nitric acid is 2:3, the volume ratio of fuming nitric acid and fuming sulfuric acid is 1:2, the reaction time is 12min, the reaction temperature is 75℃, the yield and purity are 78.1% and 99.2%, respectively. The optimal conditions based on methylation of 2,4,5-TNIK are as follows: the molar ratio of 2,4,5-TNIK, DMS and K₂CO₃ is 1:2:2, the reaction time is 20min, the reaction temperature is 70℃, the yield and purity are 71.3% and 99.4%, respectively. Therefore, compared with the conventional tank reactor process, the micro-channel reaction process has the advantages of shorter reaction time, lower dosage of nitration reagent, slightly lower reaction temperature and slightly higher yield.

The ignition energy and combustion characteristics of HTPE solid propellants were investigated by CO₂ laser ignition and combustion test system. The effects of pressure, atmosphere, initial temperature(-50—70℃)and burning rate regulator on the burning rate, flame morphology, combustion temperature and minimum ignition energy of HTPE solid propellants were analyzed. The results show that HTPE solid propellant has lower flame intensity, burning rate, and combustion temperature than hydroxyl-terminated polybutadiene(HTPB)solid propellant. The increase of temperature, pressure and oxygen content can increase the combustion intensity and decrease the minimum ignition energy of HTPE solid propellant. The minimum ignition energy of the three HTPE solid propellants(HTPE_0, HTPE_Ca, HTPE_Sr)is 0.738, 1.038 and 1.862J at -50℃, respectively. The low temperature initial environment can significantly increase the minimum ignition energy. The calcium carbonate and strontium carbonate can inhibit the burning rate of HTPE solid propellant.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.

To investigate the bubble pulsation and water jet characteristics under the gas-liquid-solid multiphase coupling effect of underwater explosions near the seabed, the Euler method was employed to establish a numerical model of underwater explosions near the seabed under different substrate/water depth conditions. The full physical process of underwater explosions near the seabed under muddy substrate conditions was simulated and compared with experimental results, which showed good agreement, verifying the effectiveness of the algorithm in solving the problem of underwater explosion bubbles near the seabed. Based on this, the influence of seabed substrate and water depth on the bubble morphology, radius, period, and water jet of underwater explosions near the seabed was discussed. The results show that under the premise that the bubbles can be split, the harder the substrate, the faster the bubbles split, and the deeper the water depth, the slower the bubbles split. The harder the substrate and the deeper the water depth, the smaller the maximum radius and period of the bubble, the larger the proportion of the bubble in the total bubble volume at the moment of splitting, and the smaller the peak velocity of the two water jets generated by splitting. During the evolution of the downward water jet, a reverse water jet will form. The harder the substrate, the greater the peak velocity of the reverse water jet. In all calculated cases, the depth parameter(H_ref)is in the range of 250—750, and the peak value of the reverse water jet velocity is positively correlated with the H_ref, and the H_ref is in the range of 750—1000, which is negatively correlated.