The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development...The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.展开更多
As a typical energetic composite,polytetrafluoroethylene(PTFE)/aluminum(Al)has been widely applied in explosives,pyrotechnics,and propellants due to its ultra-high energy density and intense exothermic reaction.In thi...As a typical energetic composite,polytetrafluoroethylene(PTFE)/aluminum(Al)has been widely applied in explosives,pyrotechnics,and propellants due to its ultra-high energy density and intense exothermic reaction.In this work,the radial gradient(RG)structure of PTFE/Al cylinders with three different PTFE morphologies(200 nm and 5μm particles and 5μm fiber)and content changes are prepared by 3D printing technology.The effect of radial gradient structure on the pressure output of PTFE/Al has been studied.Compared with the morphology change of PTFE,the change of component content in the gradient structure has an obvious effect on the pressure output of the PTFE/Al cylinder.Furthermore,the relationships of the morphology,content of PTFE and the combustion reaction of the PTFE/Al cylinder reveal that the cylinder shows a more complex flame propagation process than others.These results could provide a strategy to improve the combustion and pressure output of PTFE/Al.展开更多
Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed tha...Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed that the thermal stability can be enhanced by introducing amino groups to form intra/inter-molecular hydrogen bonds, constructing conjugate systems and designing symmetrical structures. This article aims to review the physical and chemical properties of ultra-high temperature heat-resistant energetic compounds and provide valuable theoretical insights for the preparation of ultra-high temperature heatresistant energetic materials. We also analyze the selected 20 heat-resistant energetic materials with decomposition temperatures higher than 350℃, serving as templates for the synthesis of various highperformance heat-resistant energetic materials.展开更多
The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive attention.However,screening suitable coating agents to enhance the ...The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive attention.However,screening suitable coating agents to enhance the interfacial effect to obtain high-energy and low-sensitivity explosives has long been a major challenge.In this work,HMX-PEI/rGO/g-C_(3)N_(4)(HPrGC)composites were innovatively prepared by a multi-level coating strategy of two-dimensional graphite rGO and g-C_(3)N_(4).The g-C_(3)N_(4) used for desensitization has a richπ-conjugated system and shows outstanding ability in reducing friction sensitivity.The hierarchical structure of HPrGC formed by electrostatic self-assembly andπ-πstacking can effectively dissipate energy accumulation under heat and mechanical stimulation through structural evolution,thus exhibiting a prominent synergistic desensitization effect on HMX.The results show that rGO/gC_(3)N_(4) coating has no effect on the crystal structure and chemical structure of HMX.More importantly,the perfect combination of g-C_(3)N_(4) and rGO endows HPrGC with enhanced thermal stability and ideal mechanical sensitivity(IS:21 J,FS:216 N).Obviously,the new fabrication of HPrGC enriches the variety of desensitizer materials and helps to deepen the understanding of the interaction between explosives and coatings.展开更多
Detonation performance is crucial for evaluating the power of high explosives(HEs),and the equation of state(EOS)that accurately describes the high-temperature,high-pressure,and high-temperature,medium-pressure states...Detonation performance is crucial for evaluating the power of high explosives(HEs),and the equation of state(EOS)that accurately describes the high-temperature,high-pressure,and high-temperature,medium-pressure states of detonation products is key to assessing the damage efficiency of these energetic materials.This article examines the limitations of the VLW EOS in representing the thermodynamic states of explosive detonation gas products under high-temperature and medium-to high-pressure conditions.A new gas EOS for detonation products,called VHL(Virial-Han-Long),is proposed.The accuracy of VHL in describing gas states under high-temperature and medium-to high-pressure conditions is verified,and its performance in evaluating explosive detonation and working capabilities is explored.The results demonstrate that VHL exhibits high precision in calculating detonation performance.Subsequently,the detonation performance of three new HEs(ICM-101,ONC,and TNAZ)was calculated and compared to traditional HEs(TATB,CL-20,and HMX).The results indicate that ONC has superior detonation performance compared to the other explosives,while ICM-101 shows a detonation velocity similar to CL-20 but with slightly lower detonation pressure.The detonation characteristics of TNAZ are comparable to those of the standard HE HMX.From the perspective of products,considering the comprehensive work performance(mechanical work and detonation heat),both ONC and ICM-101demonstrate relatively superior performance.展开更多
The energy release of energetic composites is severely limited by the inert alumina(Al_(2)O_(3))layer on the surface of aluminum(Al).Polytetrafluoroethylene(PTFE)could eliminate Al_(2)O_(3)layer due to its highly elec...The energy release of energetic composites is severely limited by the inert alumina(Al_(2)O_(3))layer on the surface of aluminum(Al).Polytetrafluoroethylene(PTFE)could eliminate Al_(2)O_(3)layer due to its highly electronegativity and oxidability of fluorine.However,adding PTFE particles would weaken interfacial interactions resulted in poor mechanical properties and interfacial exothermic reaction.Herein,a bridging Al-PTFE as fuel and interfacial reinforcing agent was added and used to prepare LLM-105/AlPTFE microspheres,achieving both high energy output and excellent mechanical properties.The energy release and combustion reaction performance of LLM-105/Al-PTFE microspheres are significantly improved due to high reaction heat and increased interfacial reaction area of Al-PTFE.The maximum pressure and pressurization rate of LLM-105/Al-PTFE microspheres are 164.06 kPa and 29.88 kPa/s,respectively,which are 40.11%and 16.67%higher than those of physical mixed samples.Furthermore,the tensile strength and compressive strength of LLM-105/Al-PTFE microspheres are 100.40%and 26.47%higher than those of LLM-105/Al.This work provides a new approach to improve the energy release and mechanical properties for energetic composites.展开更多
Nowadays, ultrafine explosives are widely used in military fields. Ultrafine 2,2',4,4',6,6'-hexanitrostilbene(HNS) has emerged as an optimal primer for explosion foil initiators due to its excellent therma...Nowadays, ultrafine explosives are widely used in military fields. Ultrafine 2,2',4,4',6,6'-hexanitrostilbene(HNS) has emerged as an optimal primer for explosion foil initiators due to its excellent thermal stability and high-voltage short-pulse initiation performance. However, the solid phase ripening of ultrafine HNS leads to a degradation in its impact detonation performance. Previous studies have indicated that residual dimethyl formamide(DMF), which is present in ultrafine HNS prepared using the recrystallization method, affects ultrafine HNS ripening. The mechanism of residual solvent effects on solid phase ripening of ultrafine HNS is unclear. In this work, the specific surface area(SSA) derived from small angle X-ray scattering(SAXS) was utilized for kinetic fitting analysis to explore the mechanism by which residual solvents enhance the solid phase ripening of ultrafine HNS. The results of the SSA measured by insitu SAXS under conditions of 150℃ for 40 h revealed that the sample with 0.2% residual DMF exhibited a 21.51% decrease in SSA, whereas the sample with only 0.04% residual DMF showed a decrease of 15.66%.Furthermore, the higher amounts of residual DMF accelerated the reduction in SSA with time. Kinetic fitting analysis demonstrated that reducing residual DMF would lower both the activation energy and the pre-exponential factor, consequently decreasing the rate constant of solid phase ripening. The mechanism was speculated that it primarily facilitated the Ostwald ripening(OR). Additionally, contrast variation small angle X-ray scattering(CV-SAXS) confirmed that coating of ultrafine HNS particles is an effective method for inhibiting ripening, significantly reducing both the rate and extent of ripening of ultrafine HNS. This study predicts how residual solvents impact the solid phase ripening process of ultrafine HNS and proposes strategies for enhancing the long-term stability of ultrafine explosives.展开更多
Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al_(2)O_(3))on Al particles limits combustion reactivity and ...Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al_(2)O_(3))on Al particles limits combustion reactivity and energy efficiency.Fluoride-based surface modification has been developed as an effective approach to address this issue.Here,four classical fluoropolymers(F11,F14,PVDF,PTFE)are employed as coatings to prepare core-shell Al/Fluoropolymer.The combustion experimental results demonstrate that the core-shell Al/PTFE exhibits the highest flame propagation rate(52.88 mm·ms^(-1))and pressure output(109.02 k Pa)performance.Consequently,core-shell Al/PTFE is selected as a high-energy fuel to prepare RDX/Al/PTFE microspheres via the emulsion and solvent evaporation method,which can enhance the energy performance of RDX.The effects of the core-shell Al/PTFE ratio and RDX content on the combustion heat and pressure output are systematically investigated.The peak pressure reaches a maximum of 187.8 k Pa when the mass ratio of RDX,Al,and PTFE is 60:25:10.Additionally,RDX/Al/PTFE microspheres exhibit significantly higher laser-induced air shock velocities,detonation heat,and detonation pressure than those of pure RDX and RDX/Al.The mechanism underlying the enhanced reactivity and energetic performance is attributed to the ability of PTFE to etch the inert Al_(2)O_(3)shell on the surface of Al particles,thereby improving post-combustion reactions and significantly increasing the overall energy output of RDX explosives.This work offers a novel design strategy for high-energy structural thermobaric explosives for the practical applications.展开更多
This study investigates the paradoxical detonation behavior of TKX-50,a nitrogen-rich energetic material,exhibiting higher detonation velocities but lower metal acceleration ability compared to HMX.Through experimenta...This study investigates the paradoxical detonation behavior of TKX-50,a nitrogen-rich energetic material,exhibiting higher detonation velocities but lower metal acceleration ability compared to HMX.Through experimental measurements and theoretical calculations,we propose a novel three-factor competition mechanism to explain this phenomenon.TKX-50-based PBX formulations achieved detonation velocities up to 9100 m/s,surpassing HMX-based counterparts.However,cylinder expansion tests revealed a 15%reduction in metal acceleration ability.Thermochemical measurements showed lower detonation heat for TKX-50(4900 J/g)versus HMX(5645 J/g).Our mechanism involves:(1)compositional effects prevailing at high pressures;(2)Energy release becoming essential as pressure drops;(3)Pressure-dependent product composition evolution functioning at low pressure.VLW code calculations unveiled a"crossover"in Hugoniot curves,lending support to this mechanism.This study furnishes a new framework for comprehending the performance of nitrogen-rich energetic materials,with significant implications for the design and optimization of future high-energy density materials.展开更多
Realizing effective enhancement in the thermally conductive performance of polymer bonded explosives(PBXs) is vital for improving the resultant environmental adaptabilities of the PBXs composites. Herein, a kind of pr...Realizing effective enhancement in the thermally conductive performance of polymer bonded explosives(PBXs) is vital for improving the resultant environmental adaptabilities of the PBXs composites. Herein, a kind of primary-secondary thermally conductive network was designed by water-suspension granulation, surface coating, and hot-pressing procedures in the graphene-based PBXs composites to greatly increase the thermal conductive performance of the composites. The primary network with a threedimensional structure provided the heat-conducting skeleton, while the secondary network in the polymer matrix bridged the primary network to increase the network density. The enhancement efficiency in the thermally conductive performance of the composites reached the highest value of 59.70% at a primary-secondary network ratio of 3:1. Finite element analysis confirmed the synergistic enhancement effect of the primary and secondary thermally conductive networks. This study introduces an innovative approach to designing network structures for PBX composites, significantly enhancing their thermal conductivity.展开更多
Herein,a first example of energetic-energetic cocrystal polymorphs with a 1:1 M ratio was discovered by cocrystallizing CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)with 1,3-DNP(1,3-dinitropyrazole...Herein,a first example of energetic-energetic cocrystal polymorphs with a 1:1 M ratio was discovered by cocrystallizing CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)with 1,3-DNP(1,3-dinitropyrazole).These two energetic cocrystal polymorphs(cocrystal 1 and cocrystal 2)exhibit distinct crystal packing styles,which lead to significant variations in their physicochemical properties.Notably,cocrystal 2 has a high density of 1.963 g·cm^(-3)at 170 K,exhibiting high detonation performances(9187 m·s^(-1);38.68 GPa)comparable to HMX(1,3,5,7-tetranitro-1,3,5,7-tetrazocane)meanwhile displaying an improved safety(10 J)relative to RDX(1,3,5-trinitro-1,3,5-triazinane),making it a potential high-energy,low-sensitivity energetic material.This work opens up a new strategy to deeply tune properties of energetic materials by constructing energetic-energetic cocrystal polymorphs.These energetic cocrystal polymorphs represent a new field of energetic materials that has not yet been studied.展开更多
Interaction of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)/ammonium perchlorate(AP) and its effect on mechanical sensitivity may result in some restrictions for the application of AP/HMX system in high energetic weapo...Interaction of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)/ammonium perchlorate(AP) and its effect on mechanical sensitivity may result in some restrictions for the application of AP/HMX system in high energetic weapon system. In this work, impact sensitivity test is used to study the effects of wax coating of HMX, AP and aluminum(Al) powder on sensitivity properties of HMX/AP/Al mixtures.Thermogravimetry-differential scanning calorimetry(TG-DSC) analysis has been developed to investigate the mechanism of interaction between HMX and AP during the course of thermal decomposition of HMX/AP/AI mixtures. The results show that severe interaction effect exists between AP and HMX, which causes the impact sensitivity(H_(50)) to become smaller. The impact energy(E_(50)) of mixture can be improved under the circumstances of effective separating HMX from AP by surface coating with Wax. AP may firstly engender low-temperature decomposition under the circumstance of external heat or mechanical impact, which causes the exothermic peak of HMX forward shift about 28 C. The gaseous product releasing from thermal decomposition of HMX accelerates further decomposition of AP. For HMX/AP composite system, the interactive catalysis effect between AP and HMX can be eliminated mostly by adding a great deal of Al powder(i.e. above 30%).展开更多
The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,...The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.展开更多
Boron is a very promising and highly attractive fuel because of high calorific value. However, the practical applications in explosives and propellants of boron have been limited by long ignition delay time and low co...Boron is a very promising and highly attractive fuel because of high calorific value. However, the practical applications in explosives and propellants of boron have been limited by long ignition delay time and low combustion efficiency. Herein, nano-Al and graphene fluoride(GF) as surface activated materials are employed to coat boron(B) particles to improve ignition and combustion performance. The reaction heat of nano-Al coated B/KNO_(3)and GF coated B/KNO_(3)are 1116.83 J/g and 862.69 J/g, respectively, which are higher than that of pure B/KNO_(3)(823.39 J/g). The ignition delay time of B/KNO_(3)could be reduced through nano-Al coating. The shortest ignition delay time is only 75 ms for B coated with nano-Al of 8 wt%, which is much shorter than that of pure B/KNO_(3)(109 ms). However, the ignition delay time of B/KNOcoated with GF has been increased from 109 to 187 ms. B coated with GF and nano-Al shown significantly influence on the pressure output and flame structure of B/KNO_(3). Furthermore, the effects of B/O ratios on the pressure output and ignition delay time have been further fully studied. For B/KNO_(3)coated with nano-Al and GF, the highest pressures are 88 KPa and 59 KPa for B/O ratio of 4:6, and the minimum ignition delay time are 94 ms and 148 ms for B/O ratio of 7:3. Based on the above results, the reaction process of boron coated with GF and nano-Al has been proposed to understand combustion mechanism.展开更多
The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, t...The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals.展开更多
Developing high-performance lithium ion batteries(LIBs)using manganese oxides as anodes is attractive due to their high theoretical capacity and abundant resources.Herein,we report a facile synthesis of hierarchical s...Developing high-performance lithium ion batteries(LIBs)using manganese oxides as anodes is attractive due to their high theoretical capacity and abundant resources.Herein,we report a facile synthesis of hierarchical spherical MnO2 containing coherent amorphous/crystalline domained by a simple yet effective redox precipitation reaction at room temperature.Further,flower-like CoMn2O4 constructed by single-crystalline spinel nanosheets has been fabricated using MnO2 as precursor.This mild methodology avoids undesired particle aggregation and loss of active surface area in conventional hydrothermal or solid-state processes.Moreover,both MnO2 and CoMn2O4 nanosheets manifest superior lithium-ion storage properties,rendering them promising applications in LIBs and other energy-related fields.展开更多
Metal(aluminum and boron)based energetic materials have been wildly applied in various fields including aerospace,explosives and micro-devices due to their high energy density.Unfortunately,the low combustion efficien...Metal(aluminum and boron)based energetic materials have been wildly applied in various fields including aerospace,explosives and micro-devices due to their high energy density.Unfortunately,the low combustion efficiency and reactivity of metal fuels,especially boron(B),severely limit their practical applications.Herein,multi-component 3D microspheres of HMX/B/Al/PTFE(HBA)have been designed and successfully prepared by emulsion and solvent evaporation method to achieve superior energy and combustion reactivity.The reactivity and energy output of HBA are systematically measured by ignitionburning test,constant-volume explosion vessel system and bomb calorimetry.Due to the increased interfacial contact and reaction area,HBA shows higher flame propagation rate,faster pressurization rate and larger combustion heat of 29.95 cm/s,1077 kPa/s,and 6164.43 J/g,which is 1.5 times,3.5 times,and 1.03 times of the physical mixed counterpart(HBA-P).Meanwhile,HBA also shows enhanced energy output and reactivity than 3D microspheres of HMX/B/PTFE(HB)resulting from the high reactivity of Al.The reaction mechanism of 3D microspheres is comprehensively investigated through combustion emission spectral and thermal analysis(TG-DSC-MS).The superior reactivity and energy of HBA originate from the surface etching of fluorine to the inert shell(Al_(2)O_(3) and B_(2)O_(3))and the initiation effect of Al to B.This work offers a promising approach to design and prepare high-performance energetic materials for the practical applications.展开更多
Micro-TATB particles with different sizes and 3D nanoporous TATB architectures with different specific surface areas were prepared through recrystallization to study short pulse duration shock initiation properties by...Micro-TATB particles with different sizes and 3D nanoporous TATB architectures with different specific surface areas were prepared through recrystallization to study short pulse duration shock initiation properties by electric gun technology.For micro-TATB,the initiation threshold significantly decreases with TATB average size ranging from 79.7μm to 0.5μm.For 3D nanoporous TATB architecture,the initiation threshold decreases and then increases with specific surface areas increased from 9.6 m^2/g to36.2 m^2/g.The lowest initiation thresholds are obtained for the micro-TATB with average sizes of 1.3μm and 0.5μm,and 3D nanoporous TATB architecture with specific surface area of 22.4 m^2/g.The shock initiation thresholds of micro-TATB and 3D nanoporous TATB architectures show significantly decreases with the porosity increased.The decomposition reaction and thermal conductivity properties were further investigated to understand the initial response mechanism.High porosity provides more collapse sites to generate high temperature for formation of hot spots.The low thermal conductivity and decomposition temperature could enhance the formation and ignition of the hot spots,and initial decomposition reaction of TATB.The effect of the decomposition temperature is higher than that of the thermal conductivity on the shock initiation properties.The enhanced decomposition reaction could pro mote energy release and transfer process from the ignition to the combustio n.This work offe rs a new insight to understand the effects of microstructure on the shock initiation properties and the initial response mechanism of TATB.展开更多
Trifluoroacetic acid (TFA) is corrosive and toxic,which is hard to decompose by chemical reaction and micro-biological degradation[1 -2].However,TFA is largely used for the nitrogen oxidation reaction to obtain 2,6-di...Trifluoroacetic acid (TFA) is corrosive and toxic,which is hard to decompose by chemical reaction and micro-biological degradation[1 -2].However,TFA is largely used for the nitrogen oxidation reaction to obtain 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105).Common industrial separation methods such as distillation can not be utilized for recovery of TFA because of a maximum boiling azeotrope (20.6 wt ％ water,boiling at 105.5 ℃ [3]) formed by TFA and water.Till now,there is few report about the separation method of TFA-H2O.Deng[4] et al.studied the recovery of TFA liquid in the synthesis of LLM-105 explosive,the operation processes included neutralization using strong base,concentration,acidation and distillation.Mahajan[5] et al.investigated the feasibility of using reactive distillation to recover TFA through esterification with 2-propanol,but this method was aimed to dilute aqueous solution,which is unsuitable for concentrated aqueous solution. Considering above,we explored a new broken azeotropic technique to recover TFA by adding solvent A,and then employ atmospheric distillation to recove TFA for synthesis of LLM-105.The process diagram is shown in Scheme 1.展开更多
The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined condit...The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined conditions,and the interaction of Al/Fe_(2)O_(3)nanothermite and RDX in the DDT process was studied in detail.Results show that the amount of the Al/Fe_(2)O_(3)nanothermite has a great effect on the DDT properties of Al/Fe_(2)O_(3)/RDX nanocomposites.The addition of Al/Fe_(2)O_(3)nanothermite to RDX apparently improves the firing properties of RDX.A small amount of Al/Fe_(2)O_(3)nanothermite greatly increases the initial combustion velocity of Al/Fe_(2)O_(3)/RDX nanocomposites,accelerating their DDT process.When the contents of Al/Fe_(2)O_(3)nanothermite are less than 20 wt%,the DDT mechanisms of Al/Fe_(2)O_(3)/RDX nanocomposites follow the distinct abrupt mode,and are consistent with that of RDX,though their DDT processes are different.The RDX added into the Al/Fe_(2)O_(3)nanothermite increases the latter's peak combustion velocity and makes it generate the DDT when the RDX content is at least 10 wt%.RDX plays a key role in the shock compressive combustion,the formation and the properties of the DDT in the flame propagation of nanocomposites.Compared with RDX,the fast DDT of Al/Fe_(2)O_(3)/RDX nanocomposites could be obtained by adjusting the chemical constituents of nanocomposites.展开更多
基金Sponsored by National Natural Science Foundation of China (21231002,21276026,21271023,21173021,91022006,11202193,11172276,and 11072225)the 111 Project ( B07012)+1 种基金the Program of Cooperation of the Beijing Education Commission ( 20091739006)Specialized Research Fund for the Doctoral Program of Higher Education ( 20101101110031)
文摘The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.
基金supported by the National Natural Science Foundation of China(Grant Nos.11872341 and 22075261)。
文摘As a typical energetic composite,polytetrafluoroethylene(PTFE)/aluminum(Al)has been widely applied in explosives,pyrotechnics,and propellants due to its ultra-high energy density and intense exothermic reaction.In this work,the radial gradient(RG)structure of PTFE/Al cylinders with three different PTFE morphologies(200 nm and 5μm particles and 5μm fiber)and content changes are prepared by 3D printing technology.The effect of radial gradient structure on the pressure output of PTFE/Al has been studied.Compared with the morphology change of PTFE,the change of component content in the gradient structure has an obvious effect on the pressure output of the PTFE/Al cylinder.Furthermore,the relationships of the morphology,content of PTFE and the combustion reaction of the PTFE/Al cylinder reveal that the cylinder shows a more complex flame propagation process than others.These results could provide a strategy to improve the combustion and pressure output of PTFE/Al.
基金supported by the National Natural Science Foundation of China(Grant Nos.21975127,22105102,and 22135003)Young Elite Scientist Sponsorship Program by CAST(Grant No.YESS20210074)the Fundamental Research Funds for the Central Universities(Grant No.30921011204)。
文摘Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed that the thermal stability can be enhanced by introducing amino groups to form intra/inter-molecular hydrogen bonds, constructing conjugate systems and designing symmetrical structures. This article aims to review the physical and chemical properties of ultra-high temperature heat-resistant energetic compounds and provide valuable theoretical insights for the preparation of ultra-high temperature heatresistant energetic materials. We also analyze the selected 20 heat-resistant energetic materials with decomposition temperatures higher than 350℃, serving as templates for the synthesis of various highperformance heat-resistant energetic materials.
基金the financial support from the National Natural Science Foundation of China (Grant No.51972278)the Open Project of the State Key Laboratory of Environment-friendly Energy Materials (Southwest University of Science and Technology,Grant No.20fksy16)。
文摘The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive attention.However,screening suitable coating agents to enhance the interfacial effect to obtain high-energy and low-sensitivity explosives has long been a major challenge.In this work,HMX-PEI/rGO/g-C_(3)N_(4)(HPrGC)composites were innovatively prepared by a multi-level coating strategy of two-dimensional graphite rGO and g-C_(3)N_(4).The g-C_(3)N_(4) used for desensitization has a richπ-conjugated system and shows outstanding ability in reducing friction sensitivity.The hierarchical structure of HPrGC formed by electrostatic self-assembly andπ-πstacking can effectively dissipate energy accumulation under heat and mechanical stimulation through structural evolution,thus exhibiting a prominent synergistic desensitization effect on HMX.The results show that rGO/gC_(3)N_(4) coating has no effect on the crystal structure and chemical structure of HMX.More importantly,the perfect combination of g-C_(3)N_(4) and rGO endows HPrGC with enhanced thermal stability and ideal mechanical sensitivity(IS:21 J,FS:216 N).Obviously,the new fabrication of HPrGC enriches the variety of desensitizer materials and helps to deepen the understanding of the interaction between explosives and coatings.
基金supported by the National Natural Science Foundation of China(Gant Nos.11372291 and 11902298)。
文摘Detonation performance is crucial for evaluating the power of high explosives(HEs),and the equation of state(EOS)that accurately describes the high-temperature,high-pressure,and high-temperature,medium-pressure states of detonation products is key to assessing the damage efficiency of these energetic materials.This article examines the limitations of the VLW EOS in representing the thermodynamic states of explosive detonation gas products under high-temperature and medium-to high-pressure conditions.A new gas EOS for detonation products,called VHL(Virial-Han-Long),is proposed.The accuracy of VHL in describing gas states under high-temperature and medium-to high-pressure conditions is verified,and its performance in evaluating explosive detonation and working capabilities is explored.The results demonstrate that VHL exhibits high precision in calculating detonation performance.Subsequently,the detonation performance of three new HEs(ICM-101,ONC,and TNAZ)was calculated and compared to traditional HEs(TATB,CL-20,and HMX).The results indicate that ONC has superior detonation performance compared to the other explosives,while ICM-101 shows a detonation velocity similar to CL-20 but with slightly lower detonation pressure.The detonation characteristics of TNAZ are comparable to those of the standard HE HMX.From the perspective of products,considering the comprehensive work performance(mechanical work and detonation heat),both ONC and ICM-101demonstrate relatively superior performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.T2222027 and 12202416)。
文摘The energy release of energetic composites is severely limited by the inert alumina(Al_(2)O_(3))layer on the surface of aluminum(Al).Polytetrafluoroethylene(PTFE)could eliminate Al_(2)O_(3)layer due to its highly electronegativity and oxidability of fluorine.However,adding PTFE particles would weaken interfacial interactions resulted in poor mechanical properties and interfacial exothermic reaction.Herein,a bridging Al-PTFE as fuel and interfacial reinforcing agent was added and used to prepare LLM-105/AlPTFE microspheres,achieving both high energy output and excellent mechanical properties.The energy release and combustion reaction performance of LLM-105/Al-PTFE microspheres are significantly improved due to high reaction heat and increased interfacial reaction area of Al-PTFE.The maximum pressure and pressurization rate of LLM-105/Al-PTFE microspheres are 164.06 kPa and 29.88 kPa/s,respectively,which are 40.11%and 16.67%higher than those of physical mixed samples.Furthermore,the tensile strength and compressive strength of LLM-105/Al-PTFE microspheres are 100.40%and 26.47%higher than those of LLM-105/Al.This work provides a new approach to improve the energy release and mechanical properties for energetic composites.
基金the Presidential Foundation of CAEP(Grant No.YZJJZQ2023005)the National Natural Science Foundation of China(Grant No.22375191).
文摘Nowadays, ultrafine explosives are widely used in military fields. Ultrafine 2,2',4,4',6,6'-hexanitrostilbene(HNS) has emerged as an optimal primer for explosion foil initiators due to its excellent thermal stability and high-voltage short-pulse initiation performance. However, the solid phase ripening of ultrafine HNS leads to a degradation in its impact detonation performance. Previous studies have indicated that residual dimethyl formamide(DMF), which is present in ultrafine HNS prepared using the recrystallization method, affects ultrafine HNS ripening. The mechanism of residual solvent effects on solid phase ripening of ultrafine HNS is unclear. In this work, the specific surface area(SSA) derived from small angle X-ray scattering(SAXS) was utilized for kinetic fitting analysis to explore the mechanism by which residual solvents enhance the solid phase ripening of ultrafine HNS. The results of the SSA measured by insitu SAXS under conditions of 150℃ for 40 h revealed that the sample with 0.2% residual DMF exhibited a 21.51% decrease in SSA, whereas the sample with only 0.04% residual DMF showed a decrease of 15.66%.Furthermore, the higher amounts of residual DMF accelerated the reduction in SSA with time. Kinetic fitting analysis demonstrated that reducing residual DMF would lower both the activation energy and the pre-exponential factor, consequently decreasing the rate constant of solid phase ripening. The mechanism was speculated that it primarily facilitated the Ostwald ripening(OR). Additionally, contrast variation small angle X-ray scattering(CV-SAXS) confirmed that coating of ultrafine HNS particles is an effective method for inhibiting ripening, significantly reducing both the rate and extent of ripening of ultrafine HNS. This study predicts how residual solvents impact the solid phase ripening process of ultrafine HNS and proposes strategies for enhancing the long-term stability of ultrafine explosives.
基金supported by the National Natural Science Foundation of China(Grant Nos.T2222027 and 12202416)。
文摘Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al_(2)O_(3))on Al particles limits combustion reactivity and energy efficiency.Fluoride-based surface modification has been developed as an effective approach to address this issue.Here,four classical fluoropolymers(F11,F14,PVDF,PTFE)are employed as coatings to prepare core-shell Al/Fluoropolymer.The combustion experimental results demonstrate that the core-shell Al/PTFE exhibits the highest flame propagation rate(52.88 mm·ms^(-1))and pressure output(109.02 k Pa)performance.Consequently,core-shell Al/PTFE is selected as a high-energy fuel to prepare RDX/Al/PTFE microspheres via the emulsion and solvent evaporation method,which can enhance the energy performance of RDX.The effects of the core-shell Al/PTFE ratio and RDX content on the combustion heat and pressure output are systematically investigated.The peak pressure reaches a maximum of 187.8 k Pa when the mass ratio of RDX,Al,and PTFE is 60:25:10.Additionally,RDX/Al/PTFE microspheres exhibit significantly higher laser-induced air shock velocities,detonation heat,and detonation pressure than those of pure RDX and RDX/Al.The mechanism underlying the enhanced reactivity and energetic performance is attributed to the ability of PTFE to etch the inert Al_(2)O_(3)shell on the surface of Al particles,thereby improving post-combustion reactions and significantly increasing the overall energy output of RDX explosives.This work offers a novel design strategy for high-energy structural thermobaric explosives for the practical applications.
基金support provided by the National Natural Science Foundation of China(Grant No.12102405)the Presidential Foundation of CAEP(Grant No.YZJJZQ2023008).
文摘This study investigates the paradoxical detonation behavior of TKX-50,a nitrogen-rich energetic material,exhibiting higher detonation velocities but lower metal acceleration ability compared to HMX.Through experimental measurements and theoretical calculations,we propose a novel three-factor competition mechanism to explain this phenomenon.TKX-50-based PBX formulations achieved detonation velocities up to 9100 m/s,surpassing HMX-based counterparts.However,cylinder expansion tests revealed a 15%reduction in metal acceleration ability.Thermochemical measurements showed lower detonation heat for TKX-50(4900 J/g)versus HMX(5645 J/g).Our mechanism involves:(1)compositional effects prevailing at high pressures;(2)Energy release becoming essential as pressure drops;(3)Pressure-dependent product composition evolution functioning at low pressure.VLW code calculations unveiled a"crossover"in Hugoniot curves,lending support to this mechanism.This study furnishes a new framework for comprehending the performance of nitrogen-rich energetic materials,with significant implications for the design and optimization of future high-energy density materials.
基金supported by the National Natural Science Foundation of China (Grant Nos. 22475179 and 22275173)。
文摘Realizing effective enhancement in the thermally conductive performance of polymer bonded explosives(PBXs) is vital for improving the resultant environmental adaptabilities of the PBXs composites. Herein, a kind of primary-secondary thermally conductive network was designed by water-suspension granulation, surface coating, and hot-pressing procedures in the graphene-based PBXs composites to greatly increase the thermal conductive performance of the composites. The primary network with a threedimensional structure provided the heat-conducting skeleton, while the secondary network in the polymer matrix bridged the primary network to increase the network density. The enhancement efficiency in the thermally conductive performance of the composites reached the highest value of 59.70% at a primary-secondary network ratio of 3:1. Finite element analysis confirmed the synergistic enhancement effect of the primary and secondary thermally conductive networks. This study introduces an innovative approach to designing network structures for PBX composites, significantly enhancing their thermal conductivity.
基金support for this study by the National Natural Science Foundation of China(Grant No.22275175)。
文摘Herein,a first example of energetic-energetic cocrystal polymorphs with a 1:1 M ratio was discovered by cocrystallizing CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)with 1,3-DNP(1,3-dinitropyrazole).These two energetic cocrystal polymorphs(cocrystal 1 and cocrystal 2)exhibit distinct crystal packing styles,which lead to significant variations in their physicochemical properties.Notably,cocrystal 2 has a high density of 1.963 g·cm^(-3)at 170 K,exhibiting high detonation performances(9187 m·s^(-1);38.68 GPa)comparable to HMX(1,3,5,7-tetranitro-1,3,5,7-tetrazocane)meanwhile displaying an improved safety(10 J)relative to RDX(1,3,5-trinitro-1,3,5-triazinane),making it a potential high-energy,low-sensitivity energetic material.This work opens up a new strategy to deeply tune properties of energetic materials by constructing energetic-energetic cocrystal polymorphs.These energetic cocrystal polymorphs represent a new field of energetic materials that has not yet been studied.
基金supported by the National Nature Science Foundation of China(Nos.11402238,11502243 and 11502245)
文摘Interaction of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)/ammonium perchlorate(AP) and its effect on mechanical sensitivity may result in some restrictions for the application of AP/HMX system in high energetic weapon system. In this work, impact sensitivity test is used to study the effects of wax coating of HMX, AP and aluminum(Al) powder on sensitivity properties of HMX/AP/Al mixtures.Thermogravimetry-differential scanning calorimetry(TG-DSC) analysis has been developed to investigate the mechanism of interaction between HMX and AP during the course of thermal decomposition of HMX/AP/AI mixtures. The results show that severe interaction effect exists between AP and HMX, which causes the impact sensitivity(H_(50)) to become smaller. The impact energy(E_(50)) of mixture can be improved under the circumstances of effective separating HMX from AP by surface coating with Wax. AP may firstly engender low-temperature decomposition under the circumstance of external heat or mechanical impact, which causes the exothermic peak of HMX forward shift about 28 C. The gaseous product releasing from thermal decomposition of HMX accelerates further decomposition of AP. For HMX/AP composite system, the interactive catalysis effect between AP and HMX can be eliminated mostly by adding a great deal of Al powder(i.e. above 30%).
基金National Natural Science Foundation of China (Grant No.11872013) to provide fund for conducting experiments。
文摘The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.
基金supported by the National Natural Science Foundation of China (11872341 and 22075261)。
文摘Boron is a very promising and highly attractive fuel because of high calorific value. However, the practical applications in explosives and propellants of boron have been limited by long ignition delay time and low combustion efficiency. Herein, nano-Al and graphene fluoride(GF) as surface activated materials are employed to coat boron(B) particles to improve ignition and combustion performance. The reaction heat of nano-Al coated B/KNO_(3)and GF coated B/KNO_(3)are 1116.83 J/g and 862.69 J/g, respectively, which are higher than that of pure B/KNO_(3)(823.39 J/g). The ignition delay time of B/KNO_(3)could be reduced through nano-Al coating. The shortest ignition delay time is only 75 ms for B coated with nano-Al of 8 wt%, which is much shorter than that of pure B/KNO_(3)(109 ms). However, the ignition delay time of B/KNOcoated with GF has been increased from 109 to 187 ms. B coated with GF and nano-Al shown significantly influence on the pressure output and flame structure of B/KNO_(3). Furthermore, the effects of B/O ratios on the pressure output and ignition delay time have been further fully studied. For B/KNO_(3)coated with nano-Al and GF, the highest pressures are 88 KPa and 59 KPa for B/O ratio of 4:6, and the minimum ignition delay time are 94 ms and 148 ms for B/O ratio of 7:3. Based on the above results, the reaction process of boron coated with GF and nano-Al has been proposed to understand combustion mechanism.
基金supported by the National Natural Science Foundation of China(61201391)
文摘The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals.
基金Project(JCYJ20170817110251498)supported by the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen,ChinaProject(2016TQ03C919)supported by the Guangdong Special Support for the Science and Technology Leading Young Scientist,ChinaProject(21603094)supported by the National Natural Science Foundation of China
文摘Developing high-performance lithium ion batteries(LIBs)using manganese oxides as anodes is attractive due to their high theoretical capacity and abundant resources.Herein,we report a facile synthesis of hierarchical spherical MnO2 containing coherent amorphous/crystalline domained by a simple yet effective redox precipitation reaction at room temperature.Further,flower-like CoMn2O4 constructed by single-crystalline spinel nanosheets has been fabricated using MnO2 as precursor.This mild methodology avoids undesired particle aggregation and loss of active surface area in conventional hydrothermal or solid-state processes.Moreover,both MnO2 and CoMn2O4 nanosheets manifest superior lithium-ion storage properties,rendering them promising applications in LIBs and other energy-related fields.
基金the National Natural Science Foundation of China(Grant Nos.T2222027,12202416 and 12272359).
文摘Metal(aluminum and boron)based energetic materials have been wildly applied in various fields including aerospace,explosives and micro-devices due to their high energy density.Unfortunately,the low combustion efficiency and reactivity of metal fuels,especially boron(B),severely limit their practical applications.Herein,multi-component 3D microspheres of HMX/B/Al/PTFE(HBA)have been designed and successfully prepared by emulsion and solvent evaporation method to achieve superior energy and combustion reactivity.The reactivity and energy output of HBA are systematically measured by ignitionburning test,constant-volume explosion vessel system and bomb calorimetry.Due to the increased interfacial contact and reaction area,HBA shows higher flame propagation rate,faster pressurization rate and larger combustion heat of 29.95 cm/s,1077 kPa/s,and 6164.43 J/g,which is 1.5 times,3.5 times,and 1.03 times of the physical mixed counterpart(HBA-P).Meanwhile,HBA also shows enhanced energy output and reactivity than 3D microspheres of HMX/B/PTFE(HB)resulting from the high reactivity of Al.The reaction mechanism of 3D microspheres is comprehensively investigated through combustion emission spectral and thermal analysis(TG-DSC-MS).The superior reactivity and energy of HBA originate from the surface etching of fluorine to the inert shell(Al_(2)O_(3) and B_(2)O_(3))and the initiation effect of Al to B.This work offers a promising approach to design and prepare high-performance energetic materials for the practical applications.
基金supported by National Natural Science Foundation of China(11702265,11872341 and 11602238)。
文摘Micro-TATB particles with different sizes and 3D nanoporous TATB architectures with different specific surface areas were prepared through recrystallization to study short pulse duration shock initiation properties by electric gun technology.For micro-TATB,the initiation threshold significantly decreases with TATB average size ranging from 79.7μm to 0.5μm.For 3D nanoporous TATB architecture,the initiation threshold decreases and then increases with specific surface areas increased from 9.6 m^2/g to36.2 m^2/g.The lowest initiation thresholds are obtained for the micro-TATB with average sizes of 1.3μm and 0.5μm,and 3D nanoporous TATB architecture with specific surface area of 22.4 m^2/g.The shock initiation thresholds of micro-TATB and 3D nanoporous TATB architectures show significantly decreases with the porosity increased.The decomposition reaction and thermal conductivity properties were further investigated to understand the initial response mechanism.High porosity provides more collapse sites to generate high temperature for formation of hot spots.The low thermal conductivity and decomposition temperature could enhance the formation and ignition of the hot spots,and initial decomposition reaction of TATB.The effect of the decomposition temperature is higher than that of the thermal conductivity on the shock initiation properties.The enhanced decomposition reaction could pro mote energy release and transfer process from the ignition to the combustio n.This work offe rs a new insight to understand the effects of microstructure on the shock initiation properties and the initial response mechanism of TATB.
文摘Trifluoroacetic acid (TFA) is corrosive and toxic,which is hard to decompose by chemical reaction and micro-biological degradation[1 -2].However,TFA is largely used for the nitrogen oxidation reaction to obtain 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105).Common industrial separation methods such as distillation can not be utilized for recovery of TFA because of a maximum boiling azeotrope (20.6 wt ％ water,boiling at 105.5 ℃ [3]) formed by TFA and water.Till now,there is few report about the separation method of TFA-H2O.Deng[4] et al.studied the recovery of TFA liquid in the synthesis of LLM-105 explosive,the operation processes included neutralization using strong base,concentration,acidation and distillation.Mahajan[5] et al.investigated the feasibility of using reactive distillation to recover TFA through esterification with 2-propanol,but this method was aimed to dilute aqueous solution,which is unsuitable for concentrated aqueous solution. Considering above,we explored a new broken azeotropic technique to recover TFA by adding solvent A,and then employ atmospheric distillation to recove TFA for synthesis of LLM-105.The process diagram is shown in Scheme 1.
基金supported by National Nature Science Foundation of China(No.22075230)the financial support of the doctoral research foundation(No.19ZX7102)from Southwest University of Science and Technology。
文摘The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined conditions,and the interaction of Al/Fe_(2)O_(3)nanothermite and RDX in the DDT process was studied in detail.Results show that the amount of the Al/Fe_(2)O_(3)nanothermite has a great effect on the DDT properties of Al/Fe_(2)O_(3)/RDX nanocomposites.The addition of Al/Fe_(2)O_(3)nanothermite to RDX apparently improves the firing properties of RDX.A small amount of Al/Fe_(2)O_(3)nanothermite greatly increases the initial combustion velocity of Al/Fe_(2)O_(3)/RDX nanocomposites,accelerating their DDT process.When the contents of Al/Fe_(2)O_(3)nanothermite are less than 20 wt%,the DDT mechanisms of Al/Fe_(2)O_(3)/RDX nanocomposites follow the distinct abrupt mode,and are consistent with that of RDX,though their DDT processes are different.The RDX added into the Al/Fe_(2)O_(3)nanothermite increases the latter's peak combustion velocity and makes it generate the DDT when the RDX content is at least 10 wt%.RDX plays a key role in the shock compressive combustion,the formation and the properties of the DDT in the flame propagation of nanocomposites.Compared with RDX,the fast DDT of Al/Fe_(2)O_(3)/RDX nanocomposites could be obtained by adjusting the chemical constituents of nanocomposites.
