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Aluminized explosives are widely used in underwater explosives, and their energy release follows a typical time-varying process involving two stages: explosive detonation and afterburning of aluminum powder. Simulated deep-water explosion experiments of hexanitrohexaazaisowurtzitane (CL-20)-based explosives were conducted using a deep-water explosion pressure tank to study the effect of aluminum powder combustion on the shockwave propagation and bubble pulsation of deep-water explosions. The distribution mechanism of aluminum powder afterburning energy in the process of shockwave propagation and bubble pulsation under a high hydrostatic pressure was clarified, and the effect of aluminum contents on the bubble behavior of deep-water explosion was obtained by the proposed calculation method of bubble behavior. The results showed that the pressure of the shockwave of the CL-20-based aluminized explosive was lower, and the energy released by the combustion of aluminum powder increased the pressure in the middle and end of the shockwave's trailing edge, reduced the shockwave attenuation rate, and increased the first bubble pulse pressure and pulse period. The afterburning phenomenon of aluminum powder in the CL-20 aluminized explosive in explosion bubbles under high hydrostatic pressures was captured in the simulated deep-water explosion experiment for the first time. It was proven that the combustion time of the micro-aluminum powder was at the millisecond level, and the maximum radius of the bubble increased with the afterburning of aluminum powder. The characteristic parameters of the first pulsation of the CL-20-based explosive with different aluminum content in deep-water explosions calculated by the second-order Mach accuracy bubble dynamics equation and the equation of state of the explosion products were within 7% of the experimental values. The change of the afterburning process of the aluminum powder caused by the aluminum content has a great influence on the bubble behavior, and through the design of aluminum content, ideal deep-water explosion bubble characteristic parameters can be obtained. [ABSTRACT FROM AUTHOR]

The combustion agglomeration of nano-aluminum (nAl) powder leads to incomplete combustion, which seriously hinders its application as metal fuel. In this work, nAl@AlF3 composites were produced by coating nAl with AlF3via a facile chemical deposition method. TEM and SEM analyses indicated that the AlF3 layer was evenly coated on the surface of nAl with a thickness of 4.6–9.1 nm, thereby varying the quantity of AlF3 applied. Experimental results from combustion indicated that the prepared nAl@AlF3 composites exhibit superior combustion efficiency, a higher combustion rate, and reduced combustion agglomeration as compared to raw nAl. Contrary to the widely accepted explanation that volatilization of AlF3 hinders Al combustion agglomeration, we proved that the gas–solid reaction between nAl and AlF3 plays an important role in inhibiting the sintering of nAl particles produced. The gaseous intermediate (i.e., AlOF and HF) released from the hydrolysis of AlF3 could reduce the diffusion barrier of Al2O3 to facilitate the reaction of Al core, which enhances the combustion reaction kinetics. More importantly, these gaseous products actively participate in the reaction cycle to continuously exert their catalytic effects. [ABSTRACT FROM AUTHOR]

The use of fluorinated binders can enhance the combustion properties of Al in energetic materials. The underlying mechanism is under investigation and a rational strategy in terms of application has yet to be fully developed. In this study, we have investigated the effect of using a fluorine‐modified hydroxy‐terminated polyether (HTPE) binder to cast aluminized propellants and explosives. We have focused on the combustion behavior and energy release characteristics of Al particles with and without the fluorinated binder during propellant combustion and explosive detonation. The propellants combustion process was recorded using a high‐speed camera and an infrared thermometer. The heat of detonation, detonation velocity and thermal stability of the explosives were investigated using a constant temperature calorimeter, an electrometric method and a small‐scale thermal cook‐off test, respectively. The fluorine‐modified HTPE propellant has exhibited a higher flame temperature and greater energy release efficiency than the HTPE propellant. Moreover, the fluorine‐modified HTPE propellant is characterized by smaller particle agglomerates, leading to a reduction in the mass percentage of agglomerates from 73 wt% to 42 wt%. The detonation heat of fluorine‐modified HTPE explosive increases from 75.2 % to 81 %, but the detonation velocity decreased from 7745 m/s to 7622 m/s. In addition, the fluorine‐modified HTPE binder maintained the thermal stability of explosives due to a milder decomposition before thermal runaway. [ABSTRACT FROM AUTHOR]

Aluminum hydride (AlH3), as a potential new metal fuel, has attracted extensive attention in the field of hydrogen storage materials, propellants and energetic materials due to its excellent properties. In this paper, a new organic liquid phase reduction method was used to prepare AlH3, and the microstructure and composition of the prepared samples were characterized by SEM–EDS, XRD, FT-IR, XPS, etc. The main crystal phase of the prepared AlH3 was α-AlH3, with high quality and no other impurities. The thermal decomposition behavior and non-isothermal reaction kinetics of AlH3 were investigated by TG-DSC. The results show that there are three exothermic stages in the heating process of AlH3: dehydrogenation of AlH3, first oxidation of Al, and second oxidation of Al. The activation energy of the dehydrogenation of AlH3 is 77.8675 kJ/mol (Kissinger method) and 81.4862 kJ/mol (Ozawa method), respectively. The morphology evolution of AlH3 particles during the heating process (300–3000 K) was simulated using a reaction kinetics method based on the ReaxFF force field. The response behavior of AlH3 in the instantaneous high-temperature detonation environment was investigated using the high-energy laser-induced shock wave technique. Under the impact of a high-energy laser (1006 mJ), the AlH3 sample undergoes an ultra-fast reaction and generates a large amount of plasma. The expansion of the plasma pushes the surrounding air to form a supersonic shock wave and propagates forward. The shock wave propagation velocity of AlH3 is 690.99 m/s in the range of 2.1–12.35 μs, and the higher the laser energy, the faster the shock wave propagation velocity. This study provides the basis for the application of AlH3. [ABSTRACT FROM AUTHOR]

The non-ideal behavior of aluminized explosives significantly affects the characteristics of underwater explosion shockwaves, rendering the classical model for underwater explosion shockwaves difficult to apply. In this paper, we analyze the underwater explosion shockwave characteristics of a new generation of aluminized explosives and propose a non-ideal explosive underwater explosion shockwave model incorporating a non-ideal explosive shockwave parameter correction function controlled by the Al/O ratio. First, we conducted underwater explosion tank experiments to obtain four groups of Al/O ratios of shockwave parameters of underwater explosion with aluminized explosives and analyzed the effect of the Al/O ratio on them. Subsequently, we calculated the equation of state of aluminized explosives and established a one-dimensional simulation model of underwater explosion. We verified the reliability of the mesh quality and equation of state using the experimental data. Finally, we used the model to calculate the underwater explosion shockwave parameters of aluminized explosives with Al/O ratios of 0.1–1.3. Based on data analysis, we established a calculation model of the pressure peak and energy flow density of the underwater explosion shockwave of aluminized explosives containing non-ideality correction functions. Our results demonstrate that shockwave pressure peak and energy increase and then decrease with an increase in the Al/O ratio, and the non-ideal behavior of aluminized explosives makes the shockwave energy of underwater explosion more sensitive to the Al/O ratio. The proposed model can better predict the experimental results and can be of high practical value as a general structure for underwater explosion shockwave models of other aluminized or metalized explosives. [ABSTRACT FROM AUTHOR]

In order to reduce the ignition temperature and improve the combustion efficiency of aluminum powder, three aluminum-based alloy fuels, Al–Mg, Al–Zn, and Al–Si–Mg, were prepared by the atomization method. The oxidation, ignition, and combustion performance of alloy fuels were investigated, and the results showed that, using pure aluminum powder as a reference, the weight gain of alloy fuels increased from 10% to 84%, the reaction activation energy decreased from 582 kJ·mol−1 to 208 kJ·mol−1, the alloy fuels containing Mg had good ignition response, and aluminum-based alloy fuels showed high calorific value and efficient combustion as a whole. In order to investigate the combustion behavior of alloy fuels in the solid propellant, tests were conducted on the mechanics, safety, process, and combustion properties of propellant according to the national standard, and the test results showed that, compared with the propellant made of aluminum powder with same quality, the propellant made of alloy has better mechanical properties, higher frictional sensitivity, lower electrostatic sensitivity, comparable process performance, and increased combustion calorific value and combustion speed. Engine test results confirmed that Al–Zn and Al–Si–Mg alloy fuels could effectively improve the specific impulse efficiency of the solid propellant and reduced the residual rate of the engine. [ABSTRACT FROM AUTHOR]

In this study, the crystal appearance of industrial grade 2,6-diamino-3,5-dinitropyridine (PYX) was mostly needle-shaped or rod-shaped with an average aspect ratio of 3.47 and roundness of 0.47. According to national military standards, the explosion percentage of impact sensitivity s about 40% and friction sensitivity is about 60%. To improve loading density and pressing safety, the solvent–antisolvent method was used to optimize the crystal morphology, i.e., to reduce the aspect ratio and increase the roundness value. Firstly, the solubility of PYX in DMSO, DMF, and NMP was measured by the static differential weight method, and the solubility model was established. The results showed that the Apelblat equation and Van't Hoff equation could be used to clarify the temperature dependence of PYX solubility in a single solvent. Scanning electron microscopy (SEM) was used to characterize the morphology of the recrystallized samples. After recrystallization, the aspect ratio of the samples decreased from 3.47 to 1.19, and roundness increased from 0.47 to 0.86. The morphology was greatly improved, and the particle size decreased. The structures before and after recrystallization were characterized by infrared spectroscopy (IR). The results showed that no chemical structure changes occurred during recrystallization, and the chemical purity was improved by 0.7%. According to the GJB-772A-97 explosion probability method, the mechanical sensitivity of explosives was characterized. After recrystallization, the impact sensitivity of explosives was significantly reduced from 40% to 12%. A differential scanning calorimeter (DSC) was used to study the thermal decomposition. The thermal decomposition temperature peak of the sample after recrystallization was 5 °C higher than that of the raw PYX. The thermal decomposition kinetic parameters of the samples were calculated by AKTS software, and the thermal decomposition process under isothermal conditions was predicted. The results showed that the activation energy (E) of the samples after recrystallization was higher by 37.9~527.6 kJ/mol than raw PYX, so the thermal stability and safety of the recrystallized samples were improved. [ABSTRACT FROM AUTHOR]

Polydopamine (PDA), inspired by the adhesive mussel foot proteins, is widely applied in chemical, biological, medical, and material science due to its unique surface coating capability and abundant active sites. Energetic materials (EMs) play an essential role in both military and civilian fields as a chemical energy source. Recently, PDA was introduced into EMs for the modification of crystal phase stability and the interfacial bonding effect, and, as a result, to enhance the mechanical, thermal, and safety performances. This mini-review summarizes the representative works in PDA modified EMs from three perspectives. Before that, the self-polymerization mechanisms of dopamine and the methods accelerating this process are briefly presented for consideration of researchers in this field. The future directions and remaining issues of PDA in this field are also discussed at last in this mini-review. [ABSTRACT FROM AUTHOR]

In order to improve the reaction rate and reaction degree of aluminized explosives, the micro-nano composite aluminum powder was fabricated by a new method of in situ electro-explosion. The combustion performances of the composite aluminum powder were studied. The results showed that the micro-nano composite aluminum powder was like a "sea urchin structure" with many nano-sized powders around a single micro-sized aluminum particle. The heat of combustion was 25.67 MJ/kg at 3 MPa oxygen pressure, and the rising rate of pressure was particularly obvious. The ignition performance in an air environment was much better than the micro-sized aluminum powder. At the same time, the reaction process of the micro-nano composite aluminum powder was analyzed. The reaction can be divided into three stages, the decomposition of fluororubber between 500 and 600 °C, then melting, and the first step of the oxidation of aluminum powder occurred between 600 and 700 °C. In the third stage, the micro-nano composite aluminum powder reacted violently around 1000 °C and the released energy reached 3779 J/g. The micro-nano composite aluminum powder had excellent combustion performance and a good application prospect in high-power energy storage materials. [ABSTRACT FROM AUTHOR]

A series of fluoroalcohol grafted hydroxyl‐terminated polyether (HTPE) polyurethanes (PU) elastomers were synthesized by a two‐step method. The reaction progress was investigated by chemical titration and Fourier transform infrared spectroscopy (FTIR). The glass transition temperature (Tg), mechanical properties, morphology, and thermal decomposition behavior were determined for the preliminary analysis of PUs; the oxidizability property was tested by the decomposition of PU/Al composites. The results of mechanical and morphology properties demonstrated that the mechanical strength of modified PU elastomers was effectively improved for microphase separation of the hard segment. The PU film with the optimized fluoroalcohol content shows excellent performance of 17.7 MPa (tensile strength) and 547 % (elongation at break) at room temperature. Analysis of the thermal behaviors suggests that the oxidation ability of the modified PU is enhanced by the strong electronegativity of fluorine. The oxidizing gas HF, CFx, released during fluoroalcohol decomposition reacts with the alumina shell, releasing internal reactive Al, which improves the activity of the aluminum. This study might provide a new idea for utilizing high‐performance polymer binders in composite solid propellants and casting explosives. [ABSTRACT FROM AUTHOR]

Finding new melt-cast explosives with desired properties to replace 2,4,6-trinitrotoluene (TNT) has been intensely-pursued in recent decades. However, the contradiction among high energy, low mechanical sensitivity and low-melting makes the innovation of insensitive high-energy-density melt-cast explosives an enormous challenge, so the melt-cast explosives of comprehensive properties better than TNT has not been found. Here, we show a new way to design melt-cast insensitive energetic compound by the introduction of C-F into nitroaromatics. This as-synthesized energetic compound exhibits excellent performance with a high-measured density of 1.81 g cm−3, high thermal decomposition temperature (>300°C), high detonation velocity of 8.54 km s−1, appropriate melting point (82°C) and low viscosity(6200 mpa·S), and extremely low mechanical sensitivities (impact sensitivity, >60 J, and friction sensitivity, >360 N), superior to those of current melt-cast explosives, such as TNT and 2,4-dinitroanisole (DNAN). [ABSTRACT FROM AUTHOR]

To probe the thermal decomposition mechanisms of a novel fluorinated low-melting-point explosive 3,5-difluoro-2,4,6-trinitroanisole (DFTNAN), a comparative study with trinitroanisole (TNAN) was performed under different heating conditions. The thermal decomposition processes and initial reactions were monitored by DSC-TG-FTIR-MS and T-jump-PyGC-MS coupling analyses, respectively. The results show that fluorine decreased the thermal stability of the molecular structure, and the trigger bond was transferred from the ortho-nitro group of the ether to the para-nitro group. The possible reaction pathway of DFTNAN after the initial bond breakage is the rupture of the dissociative nitro group with massive heat release, which induces the ring opening of benzene. Major side reactions include the generation of polycyclic compounds and fluorine atom migration. Fluorine affects the thermal stability and changes the reaction pathway, and fluorinated products appear in the form of fluorocarbons due to the high stability of the C-F bond. [ABSTRACT FROM AUTHOR]

In this study, fluorinated polyurethane (FPU) was prepared from dialcohol-terminated perfluoropolyether as a soft segment; isophorone diisocyanate (IPDI) as a curing agent; 1,2,4-butanetriol (BT) as a crosslinker; and 1,4-butanediol (BDO) as a chain extender. Fourier transform infrared spectroscopy (FTIR) and 1H NMR were used to characterize the structure of the FPU. The mechanical properties of the FPUs with different BDO and BT contents were also measured. The tensile strength and breaking elongation of the optimized FPU formula were 3.7 MPa and 412%, respectively. To find out the action mechanism of FPU on Al, FPU/Al was prepared by adding Al directly to FPU. The thermal decomposition of the FPU and FPU/Al was studied and compared by simultaneous differential scanning calorimetry-thermogravimetry-mass spectrometry (DSC-TG-MS). It was found that FPU can enhance the oxidation of Al by altering the oxide-shell properties. The combustion performance of the FPU propellant, compared with the corresponding hydroxyl-terminated polyether (HTPE)-based polyurethane (HPU) propellant, was recorded by a high-speed video camera. The FPU propellants were found to produce smaller agglomerates due to the generation of AlF3 in the combustion process. These findings show that FPU may be a useful binder for tuning the agglomeration and reducing two-phase flow losses of aluminized propellants. [ABSTRACT FROM AUTHOR]

In view of the low-energy explosion foil detonation system's requirements for the integration technology of high-voltage switches and technical overload resistance technology, a magnetron sputtering coater is used to sputter copper film on the surface of the substrate. The thickness is 4.0 μm, the radius of the main electrode is 4 mm, the trigger electrode is 0.6 mm and 0.8 mm, and the main gaps are 0.8 mm, 1.0 mm, 1.2 mm mm, 1.8 mm, 2.0 mm, 2.2 mm, and 2.6 mm. Copper foil three-electrode planar spark gap high voltage switches are designed and manufactured; and the static self-breakdown characteristics, dynamic operating characteristics, and discharge life characteristics of the three-electrode planar spark gap high voltage switch based on copper foil are studied in this paper. The test results show that with the increase of the main electrode gap from 0.8 mm to 2.6 mm, the self-breakdown voltage of the planar spark gap switch increases, and the working voltage also increases. When the main electrode gap is a maximum of 2.6 mm, the self-breakdown voltage of the switch can reach 3480 V, which indicates that the maximum operating voltage of the switch is 3480 V. When the charging voltage is 2.0 kV, with the increase of the main electrode gap from 0.8 mm to 2.6 mm, the minimum trigger voltage value of the planar spark gap switch increases from 677 V to 1783 V (a = 0.6 mm), and from 685 V to 1766 V (a = 0.8 mm), the switch on time is 16 ns, 22 ns, 28 ns, 48 ns, 64 ns, 77 ns, 93 ns (a = 0.6 mm), and 26 ns, 34 ns, 51 ns, 67 ns, 81 ns, 102 ns (a = 0.6 mm). With the increase of the gap between the two main electrodes of the switch, the maximum static working voltage of the three-electrode plane spark gap high-voltage switch increases, the minimum trigger voltage value also increases, and the on-time of the switch gradually becomes longer. The peak current of the discharge circuit decreases and the dynamic impedance and inductive reactance of the switch also increase; as the width of the trigger electrode increases, the minimum trigger voltage decreases, the dynamic impedance and inductance decrease, and the switch operating voltage with the same parameters is higher. The easier the switch is to turn on, the lower the minimum trigger voltage. The electrode thickness of the three-electrode plane spark gap switch has a certain influence on the field strength and the service life of the switch. The results of this study provide useful references for promoting the research and development of LEEFIs. [ABSTRACT FROM AUTHOR]

Novel aluminum–silicon (Al–Si) nanoparticles (11 ~ 12 wt.% silicon) with core–shell structure were designed and prepared by electric wire explosion in argon atmosphere. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure and composition of Al–Si powders. Oxygen bomb calorimeter was used to obtain the combustion heat released, whereas thermo-gravimetric analysis and differential scanning calorimetry (TG-DSC) were used to study the thermal oxidation process. Results showed that the particle size of Al–Si powders with d50 of 311.8 nm was mainly in the nanometer range, although some large particles of several micrometers were observed. The nanoparticles had a typical "core–shell" structure. The shell consisted of silicon chips and aluminum oxides, whereas core is mainly composed of silicon frameworks filled with aluminum. TG-DSC results showed that the thermal oxidation reaction of Al–Si nanoparticles in the air proceeded in three stages. The first stage involves the slow oxidation reaction, whereas in the second step there is a violent oxidation reaction of Al, which started at about 535.5 ℃. The third step involves the mild oxidation of Al and Si. The weight gain was 72%. The oxygen bomb calorimeter tests showed that the heat release of Al–Si powders was higher than that of pure nano-Al powders. Therefore, the Al–Si nanoparticles prepared in the present work can be considered as a promising candidate in composite energetic materials such as explosives and propellants. [ABSTRACT FROM AUTHOR]

In this paper, the effect of grain size and micromorphology of Cu foil on the velocity of the flyer of an exploding foil detonator was studied. A Cu foil with different grain sizes and micromorphologies was prepared by the physical vapor deposition sputtering method. The flyer velocity of the Cu foil was measured by the photon Doppler technique (PDT). The influence of the grain size and micromorphology of the Cu foil (which was the core transducer of the exploding foil detonator) on the flyer velocity and reacted morphology was discussed. The results show that the grain size and micromorphology of the Cu film can greatly affect the velocity and morphology of the flyer. The grain size of the Cu film is more uniform, and the stimulus response in the middle area of the bridge foil is more concentrated. In addition, the current density becomes more uniform, resulting in a better explosion performance. Consequently, the speed of the formed flyer becomes higher, leading to a smoother flyer surface, which is more conductive to energy conversion. [ABSTRACT FROM AUTHOR]

The exploding foil initiator has been developed to satisfy the requirements of modern high-performance artillery and aerospace technologies with respect to speed, consistency, and safety. This study examines the explosive process of the nine-point exploding foil bridge through simulations and experiments. The factors affecting the detonation-related performance, such as the firing circuit, detonation mode, bridge foil shapes, and output charge are analyzed and discussed. The results could provide theoretical guidance and numerical support for practical application and testing. [ABSTRACT FROM AUTHOR]

In this work, laminated ammonium perchlorate-based composite (LAPC) with high thermal decomposition performance was prepared by ice-template freezing-induced assembly strategy. Cobalt-Konjac glucomannan (Co2+-KGM) hydrosol with rich AP embedded was designed and used as a frozen precursor. LAPC was obtained from the ice-template freezing of the hydrosol precursor and crystallization of AP molecules. The structure and morphology of as-obtained composite were characterized, and the thermal decomposition performances were investigated. The results showed that LAPC materials have micro-/nano-lamellar structures with the thickness size of 20 μm, which are composed of AP micro-/nanoparticles formed in the freezing crystalline progress and uniformly dispersed Co2+-KGM coated on the surface and inside of the micro-/nanoparticles. Thermal analysis results show that LAPC-2 has a lower decomposition temperature than raw AP, which have decreased by 114.3 °C. The activation energy of LAPC-2 thermal decomposition was reduced by 87 kJ/mol from 200 kJ/mol of AP to 113 kJ/mol of LAPC-2. A possible catalytic mechanism of thermal decomposition of LAPC is proposed. Under heating condition, the Co2+-KGM molecules firstly decomposed, and Co-based oxides can be in situ generated on the surface and inside of AP particles, resulting in enhancing the catalytic contact areas. Abundant distributed nanoscale Co-based oxides boosted the thermal decomposition of AP and exhibited excellent catalytic performances. [ABSTRACT FROM AUTHOR]

Fluororubber-modified aluminum (AlF) was investigated by core–shell heat transfer model and compared with traditional aluminum with oxide shell (AlO) in terms of heat transfer effect on the reaction behavior of aluminum. Reaction delay behaviors of both AlF and AlO were calculated with diameter ranging from 200 nm to 3.2 µm at different environment temperature. Calculation results showed that AlF got the upper hand over AlO in terms of reaction delay. In the same heat transfer condition, AlF could participate in the reaction with significantly shorter delay time than AlO, which benefits the energy release of the aluminum. Ceiling shell thickness of AlF was determined according to the basic timescale and temperature profile of the explosive reaction zone. Detonation velocity test of AlF was performed with two kinds of AlO as comparisons. Test proved the AlF exhibited higher reactivity than nanoaluminum. Besides, formulation with AlF showed higher detonation velocity than that with AlO, which on the other side verified the reliability of the heat transfer model. Finally, reaction model of AlF in detonation environment was proposed containing three main procedures. [ABSTRACT FROM AUTHOR]

In order to study the accelerated aging law of nitrate ester plasticized polyether (NEPE) propellants, the mechanical properties, weight loss, adhesive network structure fracture, and stability of NEPE propellants during storage were analyzed. The results show that the maximum tensile strength σm shows good change law with the increase of storage time, and the failure of NEPE propellants is mainly strength failure. The content of the stabilizer decreased with the increase of storage time. With the prolongation of storage time, the weight loss ratio increases gradually with good regularity. The decomposition of the components in the propellant leads to the degradation of the polyethylene glycol (PEG) network structure. The thermal decomposition of the nitrate plasticizer in NEPE propellants will occur, and the products will cause the adhesive network structure to decompose and break the chain, leading to the destruction of the matrix structure. The thermal decomposition of the propellant has temperature-increasing rate dependency. [ABSTRACT FROM AUTHOR]

In this work, we reported nano-sensitized dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) with micro/nano hierarchical structures were prepared by combined with ball milling and drying technology. The samples were characterized and the results demonstrated that nano sensitized TKX-50 possessed hierarchical network-like framework microstructures composed of TKX-50 nanoparticle units with the sizes of 100 ~ 300 nm. The formation mechanism of micro/nano hierarchical structures was proposed based on the self-assembly of liquid medium evaporation-induced agglomeration in the drying process. In addition, impact sensitivity evaluation showed that the impact sensitivities (H50: 15.0 cm, explosion probability: 100%) of nano sensitized TKX-50 have more sensitive properties than raw TKX-50 (65 cm, 25%). This work can offer a new understanding for the ball milling nano-sized method in energetic materials. [ABSTRACT FROM AUTHOR]

To further enhance the performance of B/KNO3 (BPN) igniter, sintered B/MgB2 (s‐B/MgB2) powder was proposed to be used as a boron substitute. The amount of heat release was tested by oxygen bomb and thermogravimetry/differential scanning calorimetry (TG/DSC). s‐B/MgB2/KNO3 (sBPN) igniter could not release as much heat as BPN igniter in the oxygen bomb due to the reduced calorific value of the s‐B/MgB2. However, calculations show that s‐B/MgB2 reached an over 90 % heat release efficiency in oxygen bomb, compared to that of 53.34 % for boron. At heating rate of 10 K min−1 in TG/DSC experiment, 19.5 % sBPN (sBPN with 19.5 wt. % s‐B/MgB2 powder) has a heat release of 1815 J g−1 and experienced an exothermic span of 2.10 min, whereas it took 24.5 % BPN (BPN with 24.5 wt. % boron powder) 3.45 min to release 1465 J g−1. The pressure‐time curve (P‐t curve), burning rate and combustion temperature were determined. The P‐t curve indicates that the combustion pressure was more readily established with the sBPN than with the BPN. The maximum pressure rise of sBPN was 362.0 Pa ms−1, whereas the figure for BPN is 77.2 Pa ms−1. Coupled with infrared radiation (IR) temperature thermometer, the distribution of the flame temperature field during combustion was obtained. It is shown that the combustion temperature of 19.5 % sBPN igniter is approximately 800 K higher than that of 24.5 % BPN. IR images of the combustion process show that the temperature difference of the 19.5 % sBPN flame is smaller than that of the 24.5 % BPN. 19.5 % sBPN also produces more hot residue, which contains KMgF3, resulting in a longer high‐temperature duration. The higher combustion pressure and temperature and more residue may enable the sBPN to readily ignite the following charge. [ABSTRACT FROM AUTHOR]

Featured Application: We aimed to obtain a dense ε-CL-20/polydopamine core-shell structure by chemical bionic technology that can effectively inhibit the solid–solid phase transition existing for CL-20 crystals and greatly enhance the thermal safety. Obtained well-coated CL-20 particles could be employed in high-energy insensitive polymer bonded explosives (PBX), thus promoting the development of weapons and equipment. 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) is a widely used high-energy explosive for the application of energetic materials. However, the phase transformation from ε-CL-20 to γ-CL-20 restrains its further application in polymer bonded explosives (PBXs) and propellants. To inhibit the phase transition of CL-20, dopamine was first used in an efficient and facile method of in situ polymerization to passivate CL-20 crystals. The core-shell microcapsule particles were obtained, and the morphological characterization demonstrates the formation of a dense core-shell structure. The differential scanning calorimetry (DSC) and in situ X-ray diffraction (XRD) test results show that the compact and dense coating delays the ε-CL-20 crystal transformation temperature by about 30 °C, which enhances thermal stability. In addition, with the coating via polymers, the friction sensitivity of ε-CL-20 crystals decreases significantly. The findings indicate a successful application of dopamine chemistry in high-energy explosives, which provides an attractive method to modify the properties of CL-20 crystals. [ABSTRACT FROM AUTHOR]

NaClO4-based molecular perovskite (H2dabco)[Na(ClO4)3] combined with the inorganic oxidizer and organic fuel was prepared by molecular assembly strategy. The high-yield samples were obtained by the one-pot reaction of NaClO4, HClO4, and triethylenediamine (dabco). The thermal analysis results showed molecular perovskite (H2dabco)[Na(ClO4)3] with ABX3-type closely ternary molecular stacking structure had a lower decomposition temperature (381.7 °C) and a higher heat release (2770 J/g) than NaClO4 (569.2 °C and 353 J/g). The apparent activation energy of thermal decomposition process was reduced by 25 kJ/mol from 184.8 kJ/mol of NaClO4 to 159.8 kJ/mol of (H2dabco)[Na(ClO4)3]. A synergistic catalysis thermal decomposition mechanism was proposed. The H2dabco2+ from the unique ternary molecular perovskite structure can be favorable for proton excitation under thermal stimuli, and promote the formation of HClO4 and superoxide radical anions ·O2− further, resulted in the redox thermal decomposition reaction between oxidizer ClO4− and fuel dabco more completely. [ABSTRACT FROM AUTHOR]

The detonation wave propagation characteristics in micro-scale groove charges are very important for optimizing the structure of the Micro-Electro-Mechanics System explosive train and improving its detonation reliability. Focusing on the problem of detonation wave propagation of micro-scale groove charges under strong confinement, the effects of charge density, groove size and confinement are considered. A theoretical model of curved detonation wave propagation in a micro-scale groove charge under a strong confinement was established by means of equivalent mass correction. The mathematical expression for the detonation velocity was derived and a numerical calculation method of detonation velocity and shock front shape was given using MATLAB software. An experiment was designed to test the detonation velocities for micro-scale groove charges with a booster explosive. The results closely agreed with the calculations, validating the propagation model of curved detonation waves. The results show that the smaller the groove size, the bigger the detonation velocity loss and the curvature of shock front in the central axis. When the charge size was 0.6×0.6mm, the detonation velocity loss was 11.49%. The detonation velocity and maximum streamline deflection angle increase with increasing charge density and size. The increase of streamline deflection angle reduces the detonation velocity of the explosive. However, the streamline deflection angle changes by only a small amount in the micro-scale with an effect on the detonation velocity of less than 1%. The detonation velocity has a strong correlation with charge size and density. This paper contains theoretical guidance for the design and performance optimization of charge structures in the MEMS explosive train. [ABSTRACT FROM AUTHOR]

Abstract: The property of detonation wave propagation in micro‐channel charges is one of the most important research areas in the field of explosives. Based on DSD (Detonation Shock Dynamics) theory and a linear assumption for the streamline deflection angle, this paper proposes a theoretical model for curved detonation wave propagation in cylinder‐type micro‐channel charges within a strong confinement of metal tube. Further, dynamic control equations related to the detonation velocity and charge diameter are deduced, a numerical calculation method of detonation velocity and shock front shape is given, and propagation rules for detonation waves with different diameters are obtained. An experiment was designed to test the detonation velocities for micro‐channel charges with a booster explosive. The results closely agree with calculations, validating the propagation model of curved detonation waves. It was found that the detonation velocity loss and shock front curvature in the central axis decreased with increasing diameter in the calculation range. Moreover, the smaller the diameter, the greater the rate of change. It is also shown that the model is suitable for the prediction of diameter effects in micro‐channel charges, which is of significance for structural design and performance optimization in MEMS initiation systems. [ABSTRACT FROM AUTHOR]

Nano-aluminum/nitrocellulose microspheres were fabricated using electrospray technique. Effects of solvent composition, nitrocellulose content and precursor concentration on the morphology and size distribution of the microspheres were investigated. The modified materials parameters were selected to generate RDX/nano-aluminum/nitrocellulose core-shell microspheres by electrospray with a coaxial needle. The morphology of core-shell microsphere was dependent on the relative ratio between the inner and outer flow rate as well as the applied voltage. For a system with a constant inner flow rate, there is an optimal range for the outer flow rate and the applied voltage. [ABSTRACT FROM AUTHOR]

As a kind of energetic plasticizer, ester-terminated glycidyl azide polymer (GAPE) has a potential for being mixed with energetic binder glycidyl azide polymer (GAP) to enable the system a higher overall energy level. To determine whether the mentioned system can be put into practical use, TG-DSC-MS-FTIR was applied to characterize thermal behaviours of GAP, GAPE and 50/50 GAP/GAPE mixture, and VST was used to decide the compatibility of GAP and GAPE. It turns out that GAPE is compatible with GAP. Decomposition of the mixture can be divided into two steps, rapid decomposition with obvious heat release and self-catalysis decomposition, showing the same tendency with the decomposition of GAP and GAPE. Based on the heating rate of 2, 5, 10 and 15 °C min−1, the kinetics triplets of the three samples’ decomposition were calculated, and the decomposition mechanism was obtained. Results show that the decomposition process was governed by the decomposition of GAPE, which started with the scission of -N3. The critical temperatures of thermal explosion of GAP, GAPE and the mixture were also calculated. Substituting the critical temperature to the reaction rate equation to verify the decomposition process, the dominating role of GAPE in this decomposition of mixture was affirmed. Therefore, GAP/GAPE mixture has a promising future in high-energy propellants/explosives. [ABSTRACT FROM AUTHOR]

The correlation between properties and the network structure of hydroxyl terminated polybutadiene (HTPB) based polyurethanes (PUs) was studied through linear and branched structure polymer matrixes formed by toluene diisocyanate (TDI) and an aliphatic polyisocyanate curing agent (N100). The curing reactions were monitored using differential scanning calorimetry (DSC) and viscosity build-up. The swelling capacity of PUs decreased with the increase of crosslink density with a stable solubility parameter according to the equilibrium swelling test. Tensile properties of PUs cured by TDI and N100 in different stoichiometric ratios of NCO/OH groups were tested. Both breaking elongation and tensile strength were remarkably improved by N100. The thermal decomposition processes of HTPB/TDI and HTPB/N100 indicated that a branched structure has higher depolymerization temperature, and hence, improved thermal stability. In addition, PU with a branched network prevented the migration of the plasticizer during isothermal accelerated aging due to the higher crosslink density. [ABSTRACT FROM AUTHOR]

MoO3 crystals with different morphologies were prepared by hydrothermal method under different temperatures and for different reaction time. Surface morphologies, phase structures, FT-IR spectra and thermal properties of the products were investigated by SEM, XRD, FT-IR spectroscopy and DSC-TG analysis, separately. With time increased to 48 h, the surface morphology became smoother and more uniform in width distribution. The morphology of MoO3 changed from thread to belt with temperature rose from 100°C to 150°C. [ABSTRACT FROM AUTHOR]

The purpose of this study is to improve the interfacial adhesion property between epoxy resin (EP) and addition-curable liquid silicone rubber (AL-SR). A novel surface treatment agent, borosiloxane oligomers (BSiO), was synthesized, and the major chemical structure was evaluated by gel permeation chromatography, Fourier transform infrared spectra, nuclear magnetic resonance spectroscopy (Si- and B-NMR), and thermogravimetric analysis. BSiO served as surface treatment agent for EP to improve interfacial adhesion characteristics of EP and AL-SR. The adhesion strength between EP and AL-SR was measured by pull-out test, and the results indicated that the adhesion strength increased from 0.02 MPa for EP/AL-SR to 0.18 MPa for BSiO-EP/AL-SR with the failure mode from EP posts dislodgement for EP/AL-SR to rubber breakage for BSiO-EP/AL-SR. Furthermore, adhesive mechanism was analyzed and concluded that the improvement of adhesion characteristics of EP/AL-SR through the oligomers surface treatment was a result of chemical and physical bonding. The BSiO acted as binder by reacting with amino groups on EP surface through the active epoxy groups and absorbing electron clouds of phenyl groups of AL-SR chains through the boron atoms. This feature makes BSiO a superior candidate to improve the adhesion and reduce the dislodgement or exfoliation of silicone rubber or other materials possessing electron-rich groups on the molecular chains from EP in the future. [ABSTRACT FROM AUTHOR]

Nitrate ester plasticized polyether (NEPE) propellant has attracted considerable attention as a kind of high-energy propellant. To investigate the evolution of thermal properties of NEPE propellant during storage life, TG-DSC-MS-FTIR was used to determine the thermal behaviors of the propellant samples before and after 5-year natural storage. It was found out that both samples experience five reaction steps and they are attributed by the evaporation and O-NO bond breaking of nitrate, crystal transition of HMX and thermal decomposition of plasticizer, HMX and ammonium perchlorate. Decomposition process and temperature ranges of each step maintain consistency, but nitrate ester tends to decompose more than evaporate after storage. In the meantime, the area of DSC peak formed in the third step noticeably increased, which accounts for the lower thermal explosion temperature. To further study the decomposition of plasticizer and HMX, their kinetic triplets were solved. It was found out that the activation energy increases significantly on plasticizer decomposition step because of the enlargement of the nitrate's particle size. Therefore, it can be drawn that the decline of NEPE propellant's safety property after storage was contributed by the decomposition step of nitrate ester plasticizer. [ABSTRACT FROM AUTHOR]

Cyclotetramethylene tetranitramine (HMX)-coated carbon nanotube (CNT) nanocomposites with uniform structures were prepared using the recrystallization method. Characterization (SEM, TEM, XRD, BET, etc.) was performed to determine the micromorphology, crystal structure, and specific surface area. The energetic particles were homogeneously distributed on the surfaces of the CNTs, and the maximum thickness of the coating layer was approximately 120 nm, whereas the average crystal size was less than 50 nm. The test results of the thermal behavior showed that the thermal decomposition temperature decreased as the CNT content increased, and the maximum thermal conductivity was approximately 27.3 times higher than that of pure HMX. The sensitivities of the CNT/HMX nanocomposites to impact, friction, and shock were maximally reduced by 73 %, 29 %, and 74 % compared with those of pure HMX, respectively, which demonstrated a significant safety improvement. In the CNT/HMX nanocomposites, aluminum and ferric oxide were used to fabricate a new type of ignition composition. Based on comparative studies, the results showed that the ignition composition was porous and that its particles were more evenly distributed compared with the conventional counterparts. The thermal conductivity was improved by 21 %. The impact and friction sensitivities were also maximally reduced by 21 % and 27 %, respectively. The combustion heat was also increased by 9 % compared with that of a mixture of the same components. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotubes (MWNTs) functionalized with acyl azide groups were prepared via chemical modification of carboxyl groups introduced on the carbon nanotube surface. The acyl azides MWNTs have potential application in chemistry functionalization of MWNTs and energetic materials. The functionalizations of the MWNTs were characterized in detail using scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and thermogravimetry (TG). The results confirm the carboxylic acid groups converted to the desired acid azide functionalization of MWNTs. [ABSTRACT FROM PUBLISHER]

Based on the fact that the double-deck rail demonstrates excellent performance in preventing rails melting and gouging during electromagnetic launch tests, theory and simulation research studies were carried out on the lateral vibration of the double-deck rail and contact properties between the armature and the rail in this paper. We deduced the lateral vibration contact equations of the double-deck rail by simplifying the electromagnetic rail launcher as Bernoulli-Euler model based on the elastic foundation. A finite-element code was used to help us model the launch progress. The influence of the double-deck rail scheme has been analyzed. Both the characteristics of the contact surface between the rail and the armature and the displacement of the rail were considered. The results show that the double-deck rail can inhibit the propagation of bending waves and efficiently reduce rail gouging. Besides, the connection method of the two decks has much influence on this effect. [ABSTRACT FROM PUBLISHER]

The thermal behavior of the energetic material 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-tetracyclo-[5.5.0.0.0]-dodecane (HNIW or CL-20) and its mixtures with aluminum under linear temperature control condition and adiabatic condition were investigated by DSC-TG-MS-FT-IR and ARC. Two different particle sizes of aluminum powder (10 μm and 50 nm) were added into CL-20. The influence of particle size on the thermal behavior of CL-20 was studied by using of these apparatuses. The enthalpies of reaction and onset temperatures were determined for various heating rates. The kinetic parameters were found according to Kissinger method, Ozawa method, and Friedman method based on DSC data. The gaseous products from the decomposition of CL-20 and its mixtures were determined by simultaneous MS-FT-IR experiments. ARC measurements were performed to investigate the thermal stability of the samples. The onset temperature, adiabatic temperature rise, self-heat rate, time to maximum rate, and pressure-temperature profile were found from the data measured by ARC. Based on these results, the catalytic effect of aluminum powder was studied. [ABSTRACT FROM AUTHOR]

In order to optimize formulations of PBX based on Hexanitrohexaazaisowurtzitane (HNIW) and meet the application in mixed explosive, the mold powder of HNIW coated by varied binders was obtained by aqueous suspension technology. Several particle sizes of graphite were added as additive with a 0.5 % mass ratio. The experiment results showed that fluorine resin (FPM) was better than polyurethane and cis-butadiene rubber when the mass percentage of binders was fixed at 4 %. The characteristic height of HNIW/FPM (96/4) mold powder was at 28 cm (2.5 kg hammer), while that of the neat HNIW was at 15 cm merely, and the friction explosion probability fell from 100 to 70 %. The addition of flake graphite with proper grain size would reduce the mechanical sensitivity of HNIW and improved the fluxion property of HNIW-based mold powders. The thermal stability characteristic of HNIW FPM (96/4) and HNIW/FPM/G (96/4/0.5) were studied by thermogravimetric analysis (TG) at 10 °C min, the peak decomposition temperatures were at 251 and 250 °C, which were closed to that of neat HNIW(249 °C) and also identified superior thermal stability of compound. [ABSTRACT FROM AUTHOR]

Several loops are placed at one side of the rails along a straight line, and the transient current is calculated with the measured magnetic field waveforms and distances between probes and currents for the long-line current models. According to the skin effect and the deformation of rails, distances between currents and probes are hard to get for each shot. If two probes are used together, it is easier to measure the single line current waveform, without measuring the distance between probes and currents beforehand. The current waveforms can be calculated only with the calibrated distance between two probes and field waveforms. For the railgun's rail currents, we can use three loop probes. The current waveforms can be easily obtained from the three magnetic field waveforms without knowing the shift positions of the rail currents. The commercial Pearson current monitor model 1423 is used to calibrate and verify the results. The results are compared with each other for the single loop, two loops, and three loops. The results show that, while it is good to measure the transient currents with one or two loops, it is better when three loops are used. The method is especially useful for situations in which the huge Rogowski current probes are hard to use because of limited space. [ABSTRACT FROM PUBLISHER]

To analyze the variation of magnetic field waveforms above rails of the railgun during the launching period, the magnetic fields are measured by loop probes. According to the armature's different moving statements and measurement positions, magnetic waveforms are distinguished with each other. The experiment results show that magnetic field waveforms above the rails change at different positions, and the output voltages of probes become larger with the higher velocities. The truncated waveforms expand the spectrum of signals around the rails. The waveforms at different positions are compared with each other, which can inflect the magnetic field distribution along the rails during the launching period. The results are useful in analyzing the interference of the transient environment for the rail launcher and the electromagnetic interference design of railgun systems. [ABSTRACT FROM PUBLISHER]

This article presents numerical simulation of underwater explosions using a one-dimensional 'wedge' model of ANSYS-AUTODYN explicit software for nonlinear dynamics, provided by ANSYS Century Dynamics, Inc. (Canonsburg, PA, USA). Through numerical analysis of a typical underwater TNT explosion problems, the effects of the quadratic and linear viscosity on the key phenomenon of this complicated energetic physical process are conducted. The results show that appropriate values exist for these two viscosities to model the process in given mesh sizes. Based on these preliminary simulations, values of quadratic and linear viscosity, 1 and 0.034, 1 and 0.068 are determined for the ranges of scaled distance from 3 to 10 and 1.5 to 3, respectively. Effects of charge depth, charge mass, and mesh density on the shock wave and bubble pulse parameters are performed for four different explosives, 2,4,5-trinitrotoluene (TNT), H-6, pentolite, and pentaerythritol tetranitrate (PETN). All of the results are compared with empirical equations and show that the ANSYS-AUTODYN software can be used to model and capture the major features of underwater explosion phenomena at acceptable accuracy and timesaving. [ABSTRACT FROM AUTHOR]

The rail-type electromagnetic launcher (EML) has good development and applied prospects for military and civilian dual purpose. The inductance gradient is an important parameter to design the EML structure and evaluate the system performance. Based on the Biot–Savart law and current skin-effect behavior, we derive an analytic formula to predict the EML inductance gradient, which expands Batteh's formula by introducing rail thickness w and skin depth \delta. Our expression is more accurate because the geometrical parameters of both rails and armature are considered in this paper. We investigate the inductance gradient change as a function of the ratio of bore width to height s/ha, rail thickness w, and two-rail interval s. Finally, our results at different scales are compared with those of other formulas of the inductance gradient. This paper could be used directly to design and optimize the rail-type EML. [ABSTRACT FROM AUTHOR]

Renewed interest has arisen in plasma armatures as evidenced by two papers presented at the 2008 EML Symposium. It is hoped that the work at the University of Texas described in these papers succeeds. There may, however, be some uncertainties related to the nature of plasma armatures in that work. The thoughts we offer here may help. It is not yet obvious how the 6-km/s velocity limit encountered in the Canberra railgun can be overcome. In the years following this discovery, a considerable number of experiments were conducted on the subject with no clear outcome. One strategy for overcoming the velocity limit may be to vent the bore behind the armature. In order to do this, it is necessary to find out how long the armature must be to be effective. Too long would make the venting process unwieldy. Too short and the armature losses will rise to unacceptable levels. Further, the method we suggest for implementing the venting strategy may be extended to prevent damage to the railgun rails caused by the arcing current transfer from rails to armature. We examine the possibilities and implications involved in implementing these strategies. [ABSTRACT FROM AUTHOR]

In this study, we studied the synergetic effect of potassium oxysalts on combustion and ignition of nano aluminum (Al) and nano copper oxide (CuO) composites. Potassium periodate (KIO4) and potassium perchlorate (KClO4) are good oxidizers with high oxygen content and strong oxidizability. Different contents of KIO4 and KClO4 were added to nano Al/CuO and the composites were assembled by sonication. When the peak pressure of nano Al/CuO was increased ~5–13 times, the pressurization rate was improved by ~1–3 orders of magnitude, the ignition delay time was shortened by ~0.08 ms–0.52 ms and the reaction completeness was adjustable when 30–70% KIO4 and KClO4 were added into the composites. The reaction of Al/KIO4 and Al/KClO4 at a lower temperature was helpful to ignite the ternary composite. Meanwhile, CuO significantly reduced the peak temperature of oxygen released from the decomposition of KIO4 and KClO4. The synergetic effect of binary oxidizers made the combustion performance of the ternary composites better than that of the binary composites. The present work indicates that KIO4 and KClO4 are promising additives for nano Al/CuO to tune and promote the combustion performance. The ternary composites have potential application in energy devices and combustion apparatus. [ABSTRACT FROM AUTHOR]

Back Cover: Ignition and Combustion Behavior of Sintered-B/MgB2 Combined with KNO3 (Prop., Explos., Pyrotech. Keywords: Igniter; Modified Boron; Energy Release Efficiency; Flame Temperature; Ignition Capability EN Igniter Modified Boron Energy Release Efficiency Flame Temperature Ignition Capability 1012 1012 1 06/05/20 20200601 NES 200601 B The cover picture is b based on the Full Paper I Ignition and Combustion Behavior of Sintered-B/MgB SB 2 sb Combined with KNO SB 3 sb i by Yalun Sun et al., https://doi.org/10.1002/prep.201900367. Igniter, Modified Boron, Energy Release Efficiency, Flame Temperature, Ignition Capability. [Extracted from the article]

Porous nano‐aluminum@polymer microspheres with a narrow size range are fabricated to exploit the energy advantages of nano‐aluminum (nAl). Nitrocellulose (NC) and glycidyl azide polymer (GAP) act as functional binders and adhere tightly to the surface of nAl particles and aggregate them into spheres. The formed holes on the microsphere surface are considered gas diffusion channels to the microsphere interior. Confined combustion results show that nAl@GAP microspheres generate the highest peak pressure, and maximum pressurization rate of nAl@NC microspheres is comparatively higher than that of others. Given the microsphere structure, thermal behavior in air shows that the oxidation‐reaction mechanism of the microspheres is close to that of nAl particles. Interfacial reactions between nAl particles and gases produced by polymer decomposition enhance microsphere reactivity. The heat released by polymer decomposition maintains the structure, activates nAl particles, and accelerates combustion propagation, which are positively correlated with the energy content of the polymer. The unconfined test results showed that nAl@GAP microsphere combustion propagates faster than that of nAl@NC microspheres. [ABSTRACT FROM AUTHOR]

To control the explosion energy output by optimizing explosive components is a key requirement in a number of different application areas. The effect of different Al/O Ratio on underwater explosion of aluminized explosives has been studied detailedly. However, the effect of explosive percentage in the same Al/O Ratio is rarely researched, especially for Hexanitrohexaazaisowurtzitane (CL-20) based aluminized explosives. In this study, we performed the underwater explosion experiments with 1.2-kilogram explosives in order to investigate the explosion energy released from CL-20 and Octogen (HMX) based aluminized explosives. The percentage of the explosive varied from 5% to 30% and it is shown that: the shockwave peak pressure (pm) grows gradually; shock wave energy (Es) continues increasing, bubble energy (Eb) increases then decreases peaking at 15% for both formulas, and the total energy (E) and energy release rate (η) peak at 20% for CL-20 and 15% for HMX. This paper outlines the physical mechanism of Eb change under the influence of an aluminium initial reaction temperature and reaction active detonation product percentage coupling. The result shows that CL-20 is superior as a new high explosive and has promising application prospects in the regulation of explosive energy output for underwater explosives. [ABSTRACT FROM AUTHOR]