In order to further reduce the glass transition temperature(T_g)of HTPB propellants and expand their operational temperature range, the molecular structures and T_g values of high cis HTPB, anionic polymerized HTPB and type I HTPB were analyzed and compared. Propellants based on different HTPB were prepared, and their curing reaction kinetics, mechanical properties, energy performance, combustion performance, and feasibility of ignition at ultra-low temperatures were investigated. The results show that the molecular structures of HTPB has a significant influence on its T_g. The T_g of hydroxyl-terminated polybutadiene with a cis-1,4 structure accounting for 74% to 76% is approximately -101℃. Compared with type I HTPB propellants, propellants based on high cis HTPB has a lower curing reaction rate and a lower T_g. By using nonyl oleate plasticizer and optimizing the plasticization ratio, the T_g of HTPB propellant can reach -96.2℃. Compared with the propellant containing anionic polymerized HTPB and type I free-radical-polymerized HTPB as a binder, high-cis HTPB-based propellants have a lower elongation under the condition of comparable tensile strength. Verified by the BSFΦ118 engine tests and BSFΦ165 engine tests, the burning rate and energy performance of the high-cis HTPB propellant are at the same level as those of the type I HTPB propellant. High-cis HTPB-based propellants passed the -70℃ BSFΦ118 engine test, preliminary demonstrating the feasibility of high-cis HTPB propellants in ultra-low-temperature environments.

To evaluate the anti-high overload performance of HTPB propellant over a wide temperature range, based on one-dimensional elastic stress wave propagation and loading theory, the test system for high overload loading of propellant charge was developed, the theoretical design of overload amplitude and pulse width of propellant charge strip sample under the single pulse loading was realized. In addition, the waveform shaping technology was combined to achieve accurate control of high overload stress wave, and the high and low temperature control systems were coupled to realize the wide temperature range axial high overload test condition of propellant. A series of high-overload experiments with different loading pulse widths(100, 200, 300μs)of propellant samples at 12000g and 16000 g overload amplitude under high and low temperature(-50, -20, 0, 25 and 70℃)were investigated. Based on the genetic integral form viscoelastic constitutive model, the finite element analysis of the high overload test process was carried out. Combined with μCT test and finite element analysis, the variation of damage response characteristics of propellant samples with overload amplitude, pulse width, temperature under complex and high overload loading were studied. The results show that under high overload conditions, with the same overload amplitude and pulse width, the stress level increases as the temperature decreases; under the same overload amplitude and temperature conditions, the stress level increases as the pulse width increases. The stress distribution of the propellant samples at high and low temperatures show a relatively consistent pattern, with the maximum stress occurring near the end of the load climbing section and stress concentration at the bottom of the propellant grain. By taking the compressive strength varying with strain rate and temperature as the strength criterion and through the coupled analysis of the stress field, strain rate field and temperature, the structural integrity of the propellant column can be guaranteed under five different temperatures and three different pulse widths under 16000g overload. Meanwhile, the increase of temperature would inhibit the formation of damage characteristics, while the increase of pulse width under loading would promote the formation of damage characteristics.

An energetic binder based on hydroxyl-terminated polybutadiene(HTPB), doped with different ratios of nitrocellulose(NC)(10%, 20%, 30%, and 50%), was developed to study the effect of NC doping on the thermal decomposition behavior of a composite propellant(CP)comprising ammonium nitrate(AN)as an oxidizer and magnesium(Mg)as a fuel. Optimization of the propellant formulation was conducted using Chemical Equilibrium with Applications-National Aeronautics and Space Administration(CEA-NASA)software, which demonstrated an increase in specific impulse by 12.09s when the binder contained 50% NC. Fourier-transform infrared spectroscopy(FTIR)analysis confirmed the excellent compatibility between the components, and density measurements revealed an increase of 6.4% with a higher NC content. Morphological analysis using optical microscopy showed that NC doping improved the uniformity and compactness of the surface, reduced cavities, and achieved a more homogeneous particle distribution. Differential scanning calorimetry(DSC)analysis indicated a decrease in the decomposition temperature of the propellant as the NC content increased, while kinetic studies revealed a 48.68% reduction in the activation energy when 50% NC was incorporated into the binder. These findings suggest that the addition of NC enhances combustion efficiency and improves overall propellant performance. This study highlights the potential of the new HTPB-NC energetic binder as a promising approach for advancing solid propellant technology.

In order to solve the problem of reducing the damage area caused by the axial energy waste of conventional fuel air explosive, numerical simulation researches on the multiphase cloud near-field growth process of fuel air explosive were carried out. The influence mechanism of axial non equal diameter degree on the near-field growth characteristics of cloud was revealed at multiple scales. By incorporating the baroclinic effect induced by axial non equal diameter and the annular shear fragmentation of the fuel, a multiphase cloud near-field growth model of axial non equal diameter structured fuel air explosive was constructed. Based on this model, the cloud size and radial growth rate were quantitatively calculated. The results show that the axial non equal diameter structured induces a baroclinic effect on the fuel. With the increase of axial non equal diameter, the radial growth rate of multiphase clouds in the near-field stage decreases, and the axial growth rate increases. The particle size distribution along the radial direction demonstrates a gradient decay from the center outward during the near-field stage. As the axial non equal diameter degree of the device intensifies, the axial velocity component of the fuel increases, whereas the radial component decreases, leading to a morphological transition of the multiphase cloud from a “lantern shape” to an “umbrella shape”. The central cavity size of the multiphase cloud was reduced in the axial non equal diameter structure, and the continuity of the internal distribution of the cloud was strengthened. A maximum deviation of less than 6.5% between the predicted cloud size and experimental data validates the reliability of the multiphase cloud near-field growth model.

To investigate the effects of different machine oil-diesel ratios on the explosive properties of site-mixed emulsified explosives, the viscosity and particle size distribution of emulsion matrices with varying oil-diesel ratios by using digital viscometry, laser particle size analysis, and optical microscopy were examined, the internal phase structure of explosive samples was observed. The density of matrices and explosive specimens were measured through PVC tube simulations of borehole charging configurations. Detonation velocity and brisance were respectively determined by using a detonation velocity tester and lead cylinder compression method. The results reveal that as the oil-diesel ratio in explosive formulations increased from 0:5.5 to 5.5:0, the matrix viscosity rose from 1.5×10⁵mPa·s to 3.7×10⁵mPa·s. Concurrently, the sensitized bubble concentration increased while the bubble size decreased, demonstrating improved uniformity. The dispersed phase droplet size distribution narrowed significantly with distribution width decreased from 86.19μm to 6.33μm, the mean particle size reduced from 13.85μm to 2.78μm, and dispersion index declined from 6.23 to 2.27, indicating enhanced homogeneity. At 0.3% sensitizer content, the explosive density increased progressively from 0.95g/cm³ to 1.10g/cm³. Corresponding improvements in detonation performance were observed: the detonation velocity increased by 24.08% from 3155m/s to 3915m/s showing consistency with theoretical predictions from the B-W method, and the brisance increased by 34.48% from 9.05mm to 12.17mm.With increasing the sensitizer concentrations(0.3%,0.5%,0.7%), the bubble density increased and the explosive density reduced. Distinct performance trends emerged based on oil-diesel ratios: formulations with ratios ≤3:2.5 exhibited initial enhancement followed by decline in detonation parameters, while those with ratios ≥4:1.5 demonstrated progressive reduction in explosive performance characteristics.

In order to obtain the damage characteristics of the double-layer shell structure under the underwater explosion of the shelled charge, the damage test of the double-layer shell structure under the underwater explosion was carried out with a small explosive tank device, and the influence of the hollow medium at the back cavity of the inner plate, the filling medium between the inner and outer plates, the explosion position and distance and other factors on the damage characteristics of the double-layer shell were analyzed, and the damage mode of the double-layer shell structure under the underwater explosion of the shelled charge was obtained. The results show that under the contact explosion of the underwater shell charge, there are three kinds of damage modes: the overall plastic deformation of the double-layer shell, the tearing of the inner and outer plates in the shape of “mouth”, “grid” and “cross”, and the local bending or fracture deformation of the inner and outer plates and ribs. Under the same underwater contact explosion conditions, when the explosion position is at the intersection of the transverse and longitudinal ribs of the double-layer shell, the damage range caused to the inner and outer plates is larger, and the filling of the water medium between the double-layer shells greatly reduces the impact effect on the inner shell and improves the impact resistance of the inner plate of the double-layer shell.

In order to obtain the application properties of HMX containing RDX impurities, HMX/RDX composites doped with different RDX contents were prepared by solvent-non-solvent method using N,N-dimethylformamide and dimethyl sulfoxide as the mixed solvent. The morphology, structure, and thermal properties of the prepared HMX/RDX composites were characterized by SEM, XRD, FT-IR and DSC-TG, and their mechanical sensitivities were analyzed. The results show that the prepared RDX-doped HMX/RDX composites are of blocky and flat circular particles, where the particle sizes mainly distribute in the range of 0.5—3μm. The particle size of the composites decreases with the increase of the RDX-doped content, and the doping of RDX has no effect on the crystalline morphology and phase of HMX. The RDX-doped HMX/RDX composite only has one decomposition exothermic peak, which means the doping is uniform. Compared with pure HMX, the exothermic decomposition peak temperatures and apparent thermal decomposition enthalpies of RDX-doped composites decrease slightly with the increase of RDX content(less than 30%), while their mechanical sensitivity is decreased and their safety properties are improved. They can effectively replace pure HMX in some applications.

In order to make up for the small production capacity, poor stability of the production process and low production efficiency of m-dinitrobenzene(m-DNB)in the traditional kettle production process, m-DNB was synthesized based on a microchannel reactor using nitrobenzene(NB)as the raw material, ethylene dichloride as the solvent, and a mixture of fuming nitric and fuming sulfuric acids as the nitrifying agent. The effects of the molar ratio of mixed acids, molar ratio of nitric acid to NB, reaction temperature, and total flow rate of the material on the nitrification reaction were investigated, where the reaction kinetics was also studied. The results show that the optimal conditions for the reaction are 60mL/min for the total flow rate of the material, 1:4 for the molar ratio of nitric acid to sulfuric acid, 1:2 for the molar ratio of NB to nitric acid, and 40℃ for the reaction temperature, under which the yield of m-DNB is as high as 93.60%. The activation energy of the NB nitration reaction is 63.930kJ/mol, and the finger-forward factor is 1.115×10⁹ L/(mol·s). It indicates that the microchannel reactor has the advantages of high heat transfer and mass transfer efficiency, accurate control of the reaction process, and high safety.

A novel heat-resistant explosive, 2,6-bis(tetrazolylamino)-3,5-dinitro-4-pyridone-1,1'-dipotassium salt, was synthesized from 4-amino-2,6-dichloropyridine and 5-amino-1H-tetrazole by a three-step reaction of nitration, condensation, and oxidation in an overall yield of 41%. The target compound was characterized using nuclear magnetic resonance spectroscopy(¹H and¹³C), Fourier transform infrared spectroscopy and elemental analysis, and its structure was determined by single crystal X-ray diffraction. The thermal stability was investigated by differential scanning calorimetry(DSC)and thermogravimetry(TG)analyzer, the mechanical sensitivity was determined by BAM method, and the detonation properties were predicted by EXPLO5 software. The results show that the crystal of 4·5H₂O belongs to triclinic crystal system, Pī space group, with a crystal density of 1.782g/cm³(296K). The anionic ligand structure is nearly planar and exhibits face-to-face π-π stacking, which further forms a three-dimensional coordination polymer structure by coordinating with K⁺. Compound 4 has a measured density of 2.10g/cm³, a thermal decomposition temperature of 308.5℃, a detonation velocity of 7884m/s, a detonation pressure of 25.02GPa, an impact sensitivity of 20J, and a friction sensitivity of above 360N, indicating good heat resistance, low sensitivity and high energy.

To address the theoretical deviations caused by the CJ(Chapman-Jouguet)hypothesis in the calculation of detonation parameters, the LADM(Least Action Detonation Model)based on the principle of least action was adopted. In this model, the entropy principle is used to determine the endpoint of the detonation process, while the Hamilton principle is applied to describe the reaction zone of the detonation, thereby replacing the traditional CJ hypothesis. The model was used to calculate detonation velocity parameters for 29 types of typical gaseous, liquid, and solid elemental explosives, including metallic hydrogen and all-nitrogen compounds, as well as mixed explosives. The detonation heat values were measured with calorimetric bomb, and the adiabatic index closely matched theoretical values. The results show good agreement between calculated and experimental data, demonstrating strong universality of the method. This indicates that the proposed approach can effectively calculate detonation parameters of novel explosives, offering solid theoretical guidance and promising application prospects.

In order to accurately evaluate the reaction level of ammunition charge under the impact of high-speed fragments,with the help of an overloading setup,the photon Doppler velocimeter(PDV), high-speed photography, shock wave overpressure measurements, self-short-circuit electric probes, together with static explosion tests,were used to study the response levels of the HMX-based charge(PBX-8)under different impact conditions caused by high speed fragments. The results indicate that the qualitative evaluation of the non-reaction level and combustion level was mainly based on the remaining debris and the high-speed images of the reaction process.For the accurate evaluation of deflagration, explosion, and detonation levels,the quantitative values of reaction intensity were obtained from quantitative parameters such as shock wave overpressure, shell expansion velocity, and reaction time,etc. The quantification of the reaction intensity between the deflagration and explosion reaction levels exists a one order of magnitude difference. Moreover, the different impact positions of fragments on the charge can affect the final reaction intensity of the charge under the same impact velocity.

A numerical computational model of the hybrid rocket motors was established based on the heat transfer between gas and solid fuel, the effects of oxygen swirl intensity, oxygen mass flux and combustion chamber pressure on the combustion efficiency were studied using polyethylene as fuel and oxygen as oxidant. The results show that the flame is far from the burning surface and the gas reaction mainly occurs near the axis of high oxygen content when oxidizer is injected in rectilinear form, causing a significant amount of fuel residue in the rear combustion chamber cavity, which leads to a low combustion efficiency. A significant advantage in enhancing the gas mixing is exhibited as S > 0.2, and the combustion increases by 5.25% when S increases from 0.167 to 0.444. The combustion efficiency increases by 1.1% with the increase of 25kg/(m²·s)in the mass flux of O₂. Chamber pressure has little influence on the combustion efficiency and burning surface regression rate.

A numerical computational model of the hybrid rocket motors was established based on the heat transfer between gas and solid fuel, the effects of oxygen swirl intensity, oxygen mass flux and combustion chamber pressure on the combustion efficiency were studied using polyethylene as fuel and oxygen as oxidant. The results show that the flame is far from the burning surface and the gas reaction mainly occurs near the axis of high oxygen content when oxidizer is injected in rectilinear form, causing a significant amount of fuel residue in the rear combustion chamber cavity, which leads to a low combustion efficiency. A significant advantage in enhancing the gas mixing is exhibited as S > 0.2, and the combustion increases by 5.25% when S increases from 0.167 to 0.444. The combustion efficiency increases by 1.1% with the increase of 25kg/(m²·s)in the mass flux of O₂. Chamber pressure has little influence on the combustion efficiency and burning surface regression rate.

Thermoplastic composite solid propellant with solid content of 86.5% was prepared by resonance acoustic mixing(RAM)process by using ethylene ethyl acrylate copolymer based thermoplastic binder(EEA)as matrix, aluminum powder and ammonium perchlorate as energetic solid fillers. The rheological parameters of thermoplastic binder/propellant were measured by rheological method. The rheological properties of thermoplastic binder and thermoplastic propellant were studied systematically, including apparent viscosity, modulus, thixotropy, strain scan, frequency scan, temperature scan and time scan. The results show that the prepared propellant has good formability and flow property. The EEA-based thermoplastic propellants exhibit obvious thixotropy, and the apparent viscosity decreases with the increase in the shear rate, showing obvious pseudoplastic fluid characteristics. The viscoelastic properties of EEA-based thermoplastic propellants are frequency- and temperature-dependent, showing a second plateau at low frequency and solid-liquid transition at high temperature. Unlike thermoset propellants, the modulus and viscosity of thermoplastic propellants remain essentially constant over time.

To solve the problems associated with difficulty in reaction controlling, high reaction temperature, and low yield in the synthesis of isopropyl nitrate(IPN)by conventional process, a heart-shaped microchannel reactor was used to synthesize IPN by using isopropanol as raw material and dichloromethane as solvent, through the reaction of fuming nitric acid and acetic anhydride. The effects of factors such as the molar ratio of isopropanol, fuming nitric acid and acetic anhydride, the mass fraction of fuming nitric acid, total flow rate, and reaction temperature on the nitrification reaction were investigated. Results show that at the temperature of 10℃, total flow rate of 60mL/min, mass fraction of fuming nitric acid of 98%, molar ratio of isopropanol, fuming nitric acid and acetic anhydride of 1:1.2:0.9, and mass ratio of isopropanol and dichloro-methane of 1:1, the conversion rate can reach to 99.83%. A homogeneous kinetic model for the nitration reaction of IPN was established.The activation energy is 37.05kJ/mol by fitting, and the pre-exponential factor is 4.93×10⁴L/(mol·s).

In view of the technical challenges brought by the industrialization and engineering application of resonance acoustic mixing(RAM)technology, the current state of researches on application effect, efficiency, safety and influencing factors of RAM was summarized, and the development directions in the future are prospected. RAM technology can not only be applied to simple mixing to achieve uniform dispersion of material components, but also can be applied to chemical reaction, cocrystal, surface treatment and other aspects because of its advantage of efficient interface contact among mixed materials; In its applicable fields, RAM has obvious efficiency and scale-up advantages, and the maximum efficiency can even be improved by hundreds of times compared with the traditional process, and there is almost no scaling effect; moreover, because of its lower shear characteristics without paddle, compared with vertical kneaders, screws, mills and other high shear devices, the structural integrity of the material is better maintained, which is conducive to process the sensitive and hazardous materials. At present, research mainly focuses on the laboratory experiment and lacks unified mechanism cognition on some processing phenomena. In the future, further research should be carried out on the process mechanism, scale-up characteristics, and comprehensive efficiency, so as to accelerate the engineering application of RAM.100 References are attached.

In order to reduce the characteristic signal of solid propellant, while maintaining the total solid content of the formulation at 84%, the aluminum powder content is gradually decreased from 16% to 4%. Laser ignition combustion tests and condensed phase combustion product analysis were carried out, and the influence of metallic aluminum content on the combustion characteristics of solid propellants was obtained. The results show that with the gradual decrease of aluminum content, the overall combustion stability of the HTPB propellant weakens, the flame oscillation amplitude and the ignition delay time increase, the linear combustion time becomes longer, and the combustion temperature decreases. With the reduction of aluminum content, the aluminum agglomeration at the burning surface gradually develop from conventional ‘molten aluminum agglomeration balls' to ‘flakes'. After ultrasonic dispersion, particle size analysis shows that the size and number of large particle agglomerates are decreasing. Moreover, the combustion efficiency increases first and then decreases with the increase of aluminum content, and is optimal at the aluminum powder content of 8%, reaching 88.1%.

In order to study the impact energy release and crushing behavior of N b₁Zr₂Ti₁W₂ high entropy alloy, the test method of dynamic energy release testing during the bullet-target interaction was provided by ballistic gun and quasi-closed reaction tank. The impact energy release process and dynamic crushing law were analyzed, and the cumulative mass distribution model of fragments was established. The impact induced energy release characteristics of N b₁Zr₂Ti₁W₂ high entropy alloy were studied.The results show that N b₁Zr₂Ti₁W₂ produces “explosion-like” energy release effect under high-speed impact load, which releases a large amount of chemical energy mainly due to the oxidation reaction of Zr element. The 5.07g alloy material can produce 0.176MPa overpressure in the 32.7L quasi-closed vessel at the speed of 1631m/s. The distribution of fragments follows the power law, and the size of fragments is closely related to the energy release.

To enhance the combustion efficiency of boron, n-B/n-Ti/NC ternary spherical agglomerated particles were prepared by using swelling, adsorption, dissolution agglomeration, and prilling method.SEM and DSC were used to analyze the microscopic structural properties and thermal stability of the particles, and a laser ignition system was used to investigate their combustion characteristics.The results show that n-B and n-Ti can be adsorbed into the swelling NC capillary tubes, resulting in the formation of ternary spherical agglomerate particles with uniform distribution of elements, high density and high sphericity with n-Ti as a combustion improver and n-B as high-energy combustor.At the mass ratio of NC 17%, n-Ti 8% and n-B 75%, the agglomerated particle exhibits the shortest ignition delay time(3.42ms)and combustion time(8ms).The compatibility of n-B, n-Ti and NC is very good, and the agglomerated particles have excellent thermal stability.

To enhance the combustion efficiency of boron, n-B/n-Ti/NC ternary spherical agglomerated particles were prepared by using swelling, adsorption, dissolution agglomeration, and prilling method.SEM and DSC were used to analyze the microscopic structural properties and thermal stability of the particles, and a laser ignition system was used to investigate their combustion characteristics.The results show that n-B and n-Ti can be adsorbed into the swelling NC capillary tubes, resulting in the formation of ternary spherical agglomerate particles with uniform distribution of elements, high density and high sphericity with n-Ti as a combustion improver and n-B as high-energy combustor.At the mass ratio of NC 17%, n-Ti 8% and n-B 75%, the agglomerated particle exhibits the shortest ignition delay time(3.42ms)and combustion time(8ms).The compatibility of n-B, n-Ti and NC is very good, and the agglomerated particles have excellent thermal stability.

In order to improve the reaction efficiency of Al-Mg-B alloy powder in the application of energetic materials, Al-Mg-B alloy/fluororubber composite materials with different fluororubber contents were prepared by solvent evaporation using fluoro-rubber F₂₆₀₃ as the coating. The particle size, morphology, thermal performance, and combustion performance of the modified composite particles were characterized and tested by laser particle size analyzer, scanning electron microscope(SEM), transmission electron microscope(TEM), simultaneous thermal analysis TG-DSC, and oxygen bomb calorimeter. The results show that the composite materials prepared have a high degree of encapsulation.By TG-DSC tests, it is found that the F atoms introduced by the fluororubber coating have a significant combustion assisting effect on the alloy powder, and the main exothermic peak of the Al-Mg-B alloy/fluororubber composite material with a mass ratio of 3:20 between F₂₆₀₃ and Al-Mg-B alloy powder is 164℃ earlier than that of the raw material Al-Mg-B alloy powder. The best particle size uniformity and exothermic performance of the modified composite particles are obtained when the mass ratio between F₂₆₀₃ and Al-Mg-Balloy powder is 2:20, with a median particle size of 77.310μm and a combustion heat of 24.290kJ/g.

In order to study the effect of microwave ignition on the ignition and combustion performance of Ti/CuO, Ti/CuO composite microspheres with oxygen-fuel ratio(Ф)of 1—3 were prepared by electrostatic spraying method.The effects of the oxygen-fuel ratio on the microwave ignition delay time in the open system, combustion velocity in the micropipes and the pressurization rate of constant volume combustion in the closed system were obtained for Ti/CuO.The flame temperature distribution diagrams of microwave ignition and thermal ignition were obtained by the calculation of combustion images with the RGB colorimetric method. The results show that Ti/CuO ignition combustion performance increases and then decreases with the increasing of oxygen-fuel ratio.When Ф=2.5, the microwave ignition delay time is the shortest(120ms), the peak pressure is the largest(412.76±28.74kPa), and the combustion velocity in the microtubes is the maximum of 2.38m/s.In addition, the microwave ignition flame temperature(1500—2000℃)and flame area are significantly larger than those of the thermal ignition.The main reason is that the unreacted condensed phase and ionization of combustion gas products are heated by the microwave strong electromagnetic field, and then produces the high temperature plasma,which improves the condensed phase thermal effect and the flame thermal radiation and enhances combustion performance.

To improve the stability of aluminum-lithium alloy(Al-Li), the surface coating treatment was performed with self-made polyhydroxypolyester and polydopamine, respectively, to obtain Al-Li@PL and Al-Li@PDA. The morphology and structure were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS), and the interfacial mechanism was discussed. The moisture and heat stability of Al-Li@PL and Al-Li@PDA were investigated by dryer balance method. The thermal decomposition of samples were analyzed by oxygen bomb calorimetry and thermogravimetric differential scanning calorimetry, and the compatibility of the sample with 1,2, 4-butantriol nitrate(BTTN)was evaluated by non-isothermal thermal decomposition kinetics. The results show that good adhesion and functional groups(hydroxyl, carboxyl and amino)are the key factors to form stable coating layers. The heat of combustion values of Al-Li, Al-Li@PL and Al-Li@PDA are 30957, 30852 and 30589J/g, respectively, and the loss rate value after coating is less than 1%. The oxidation heat release mode does not change, and the maximum oxidation heat release peak temperature move back by 13℃ and 2℃, respectively. Both Al-Li@PL and Al-Li@PDA do not react strongly with water at 80℃, their hygroscopic weight gain rates decrease from 177.42% to 5.32% and 2.58% at 75% humidity for 30 days, respectively, their compatibility with BTTN increase from level 5 to level 1.

Due to the issue of high parallel deviation in the explosion heat test results of the composite solid propellants, using the thermostatic calorimeter, carry out the accurate test research of composite propellant explosion heat from the three aspects of clarifying the definition of explosion heat, standardizing experimental conditions and improving experimental devices. The results show that the measured values of the combustion heat release of the propellant using its own oxidizing agent tends to increase significantly with the reduction of propellant particle size and the increase of the sample amount. Therefore, the single quality of the propellant explosion heat test sample should be less than 0.14g, and the quality of the propellant sample should be more than the quality of the sample used to measure stable maximum heat release. The pressure measuring element is installed on the oxygen bomb of the calorimeter to realize the whole test record of the pressure in the oxygen bomb during the calorimetry process, and the pressure detection before ignition guarantees the effectiveness of displacing air in oxygen bomb. The maximum pressure in the oxygen bomb provides a basis for eliminating the outliers of inadequate combustion. Combined with the final pressure and the oxygen bomb volume in the experiment, the test of constant pressure explosion heat is realized.

To study the fragmentation forming characteristics of 3D printed fragmentation warhead shells, a water medium fragmentation recovery experiment was conducted on the centrally pre-controlled channel steel shell melted by selective laser melting(SLM). By comparing the shell fragment forming conditions of different charge length to diameter ratios, pre-controlled groove depth ratios, and network shapes, the influence of pre-controlled groove parameters on the fragment morphology was clarified, and its fracture mode was discussed. The results indicate that the central pre-controlled grooves significantly improve the fragmentation controllability through directional guidance, achieving fragment mass recovery rates of 87.09%—94.42% and reach the maximum complete fragment generation rate of 99.60%. There is a critical threshold for the charge length to diameter ratio. When the length to diameter ratio of the charge was below 2.1, the complete fragment generation rate remained stable at 87.62% with theinter-connected fragments rate at 22.40%, whereas when it exceededg 2.1, the complete fragment generation rate drop sharply to 70.37% and the inter-connected fragments rate rise to 69.44%. Inter-connected fragment count exhibited a significant negative correlation with pre-controlled groove depth ratio η, while complete fragment generation rate increased markedly with higher η. Parallelogram and rhombus mesh shapes demonstrated superior fragmentation uniformity compared to the square meshes, with complete fragment generation rates of 96.09% and 99.60%, respectively. Fracture mode analysis revealed the tensile-dominated failure along the axial direction, shear failure at the inner circumferential wall, and tensile failure at the outer wall. When η exceeded 53.3%, the shear band width at the outer wall converged to match that of the inner wall.

In order to investigate the response characteristics of PBX charge with shell and their impact safety under concentrated jet impacts, detonation experiments were conducted by using two types of jet sources: 50mm and 81mm at different blast heights. A dedicated experimental setup was designed to measure the force field during bombardment, as well as the pressure at the bottom of the projectile and within the projectile itself during the attenuation process of pressure and stress in impact detonations. Numerical simulations of the experimental process were carried out by using LS-DYNA. The effect of jet diameter and burst height on the impact initiation of cased explosives were analyzed. The critical detonation conditions of PBX charge with shell under different caliber jets are provided. The results indicate that when PBX charge with shell at 2, 4, or 6 times its own diameter explosion height can be detonated by a 50mm jet source, resulting in detonation reaction. When exposed to an explosion height equal to 3 or 5 times its own diameter, a PBX charge with shell can be detonated by 81 mm jet source; however, no detonation reaction occurs if the explosion height is increased to 8 times its own diameter. When the PBX undergoes a complete detonation reaction, the shock wavepressure at the bottom of the projectile reaches 23GPa, and the stress wave strength at a distance of 100mm from the top of the steel column at the bottom of the projectile is 600MPa. The simulation results demonstrate excellent agreement with corresponding experimental findings. Concurrently, the critical explosive heights of jet source impact shell charge with 50mm and 81mm shaped covers are 9 and 7 times greater their diameters, respectively. This indicates that the caliber jets diameter has a greater influence on its inherent damage capability compared to the explosion height. When the remaining energy of the jet flow penetrating the casing exceeds 38.4mm³/μs², it will trigger a detonation reaction.

To investigate the enhancement effects of free hydrogen produced by metal hydrides on the damage performance of fuel air explosive(FAE), A 20L spherical liquid explosion test system and the colorimetric temperature measurement technology were used to study the effects of different matrix liquid fuels and metal additives on the shock wave and thermal damage performance of FAE. The results show that epoxypropane(PO)has the best explosion performances of the three liquid matrix fuels commonly used in FAE. When titanium hydride(TiH₂)powders are added to PO, the explosion overpressure, maximum pressure rise rate and maximum average temperature of the mixed fuels increase first and then decrease with the increase of TiH₂ powders content, reaching the maximum values when the mass fraction of TiH₂ powders was 35%, namely, 1.21MPa, 68.73MPa/s and 2398K, respectively. Compare to Ti-PO mixed fuels, the TiH₂-PO mixed fuels has more continuous combustion flame and more excellent explosion performances at the same mass concentration. The research results indicate that as a potential high-energy additives, TiH₂ could be effectively applied to FAE to improve its explosion characteristics and enhance the shock wave as well as the thermal damage performances.

Regarding the problem of insufficientfire transfer rate of black powder, the nano-sulphur/RGO composite(RGS)wasprepared based on growth of nano-S on RGO in-situ, then mixed with KNO₃using ice template method to get KNO₃/RGS composite(RGPS). The morphology, composition, thermal decomposition and combustion performance were characterized by FE-SEM, XRD, BET, DSC and HSVR and the performances of KNO₃/RGS composite(RGPS)were compared with that of the physical mixture. The results show that nano-S is anchored in situ on RGO nanosheets and KNO₃ is embedded in RGS. The average diameter of the size of KNO₃ is about 3μm. The BET surface area of RGPS composite is about 8.1m²/g, which is much larger than 4.2m²/g of the physical mixture. The exothermic peak temperature of RGPS is lower about 13.6℃ than that of the physical mixture, the amount of released heat increased by 82.4%. The reaction activation energy of RGPS composite is 153kJ/mol, reduced by 16kJ/mol compared to the physical mixture. Compared with black powder physical mixture and RGPS physical mixture, the average combustion speed of RGPS composite is increased by 220.3% and 182.1%, respectively. The strategy can enhance the thermal decomposition and combustion performance of RGPS.

In order to study the ignition and explosion properties of micro-nano self-assembled and physically mixed aluminum powder materials, the ignition sensitivity, flame propagation characteristics and explosion parameters of the materials were studied through a 1.2L Hartmann tube and a 20L ball explosion test system. The results show that compared with Al-T4 micron aluminum powder, nano-aluminum powder can significantly reduce the ignition energy of aluminum powder materials.And the ignition sensitivity of the self-assembly process is further increased compared with that of aluminum powder materials with physical mixed process. In terms of the flame propagation speed, the high reaction rate of a small amount of nano-aluminum powder can accelerate the reaction of micron aluminum powder, and the self-assembled aluminum powder is easy to ignite and the heat transfer is more efficient due to the overall synergistic effect of micro-nano aluminum powder. In the 20L ball explosion test system, the maximum explosion pressure and explosion index of self-assembled and physical mixed aluminum powder with 5% mass fraction of nano content are 0.72MPa, 0.75MPa, 43.21MPa·m/s and 31.49MPa·m/s at 500g/m³. The maximum explosion pressure and explosion index of self-assembled and physical mixed aluminum powder with 10% mass fraction are 0.84 and 0.68MPa at 1000g/m³. The explosion pressure and explosion index of 5% mass fraction of nano aluminum powder increase first and then decrease with increasing the concentration, and the explosion pressure and explosion index of aluminum powder with 10% mass fraction increase with the increase of concentration. The explosion power of the composite system isnot only related to the activity, but also has a certain relationship with the calorific value of the powder.

In view of the poor description of 2,6-diamino-3,5-dinitropyrazine-1-oxide(LLM-105)by the ReaxFF initial force field, a JAX-ReaxFF framework strategy based on the gradient descent algorithm was adopted to reparameterize the ReaxFF reactive force field, paying much attention to the dissociation changes of the potential energy surface of different bonds and bond angles. The reaction mechanism of LLM-105 was analyzed in the simulation of reactions at different temperatures and thermal decomposition rates. The results indicate that at 1500 K, the molecular reactions mainly involved polymerization and dehydrogenation. As the temperature gradually increased, the reaction pathways of LLM-105 showed new changes. When the temperature is not less than 2000K, in addition to the original polymerization and dehydrogenation reactions, the cleavage of C—NO₂ bonds and C—NH₂ bonds were also observed. It is worth noting that the C—NO₂ bond became the key factor in triggering this series of reactions. As the C—NO₂ and C—NH₂ bonds in the molecules began to undergo homolytic cleavage, the formation of intermediates HON₂, NO₂ and NH₃ were formed. These intermediates underwent complex interactions and eventually generated stable products such as N₂, H₂O and CO₂, indicating that the force field can effectively simulate the changes in chemical reactions at different temperatures and heating rates.