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The problem of the space debris is an important aspect of the on-ground casualty risk reduction. Some articles, like fuel tanks made of titanium alloy, survive during the atmospheric post-mission re-entry and impact the Earth's surface, thus posing a serious hazard. A pyrotechnic device is proposed to bring an additional heating of space debris at a certain altitude promoting its destruction and fragmentation into smaller parts during re-entry. 3D thermal modeling of the non-stationary thermal wave propagation through the system ‘pyrotechnic device - fuel tank wall’ has been performed alongside with extensive experimental testing. The pyrotechnic composition (namely, thermite), the design of the pyrotechnic device, the conjunction between the device, and the target plate surface were optimized during modeling. The first level of experimental verification included lab-tests with laser heating. At the second level, large-scale tests were conducted within the hypersonic wind tunnel to achieve the conditions closest to the atmospheric re-entry. The presented results reveal the usefulness of pyrotechnics for space applications; and the performed thermal engineering approach can be extended to materials other than titanium to decrease the on-ground casualty risk of space debris.

Актуальность исследования. Один из лидеров по производству алюминиевых порошков в России ООО "СУАЛ ПМ" перешел от выпуска грубодисперсных порошков к производству микронных порошков, имеющих более высокую реакционную способность. Микропорошки алюминия применяются во многих отраслях промышленности: порошковой металлургии, самораспространяющемся высокотемпературном синтезе новых материалов, водородной энергетике, пиротехнике и ракетных топливах. Повышение реакционной способности порошков алюминия в различных процессах приводит к понижению энергозатрат и экономии ресурсов. Цель: получение и объяснение экспериментальных данных по изменению параметров активности микропорошков алюминия после их облучения в зависимости от дозы γ-облучения. Объекты: микропорошки алюминия АСД-6, АСД-6М. Методы: дифференциальный термический анализ, рентгенофазовый анализ, методика облучения микропорошков алюминия [gamma]-излучением, методика расчета параметров активности порошков алюминия. Результаты. Получены количественные показатели реакционной способности микропорошков алюминия АСД-6 и АСД-6М до и после облучения [gamma]-излучением изотопа Со{60} с энергией 1,17 и 1,33 МэВ, т. е. энергией существенно ниже порога фотоядерных реакций. Дозы облучения образцов порошков составляли 1, 2, 4, 8 и 10 Мрад. После [gamma]-облучения температура начала окисления микропорошков снизилась максимально на 90 и 85 °С; максимальная скорость окисления возросла на 83 и 36 %; степень окисленности (при нагревании до 1250 °С) повысилась на 5,1 %, и минимально понизилась на 1,3 % для микропорошков АСД-6 и АСД-6М, соответственно. Удельный тепловой эффект окисления после [gamma]-облучения всеми дозами был больше, чем для необлученных порошков. Максимальные значения удельного теплового эффекта для АСД-6 на 199,5 кДж/моль, а для АСД-6М - на 134,8 кДж/моль больше тепловых эффектов, чем для необлученных порошков, что существенно превышает стандартную теплоту плавления алюминия (10,8 кДж/моль). Следовательно, такое состояние системы "алюминий - оксид алюминия" характеризуется запасенной энергией в 9 раз больше стандартной теплоты плавления алюминия, что с позиции классической термодинамики невозможно. В то же время известно, что запасание энергии в нанопорошках происходит за счет формирования двойного электрического слоя в частицах алюминия. The relevance of the research. One of the leaders in production of aluminum powders in Russia OOO "SUAL-PM" has passed from production of coarse powders to production of micron powders with higher reactivity. Aluminium micropowders are used in many branches of industry: powder metallurgy, self-propagating high-temperature synthesis of new materials, hydrogen energy, pyrotechnics and rocket fuels. Increase of aluminium powders reactivity in various processes leads to reduction in energy consumption and resource saving. The main aim of the research was to obtain and explain experimental data on changes in activity parameters of aluminium micropowders after radiation exposure, depending on the [gamma]-radiation dose. Objects: micron-scaled aluminium powders ASD-6, ASD-6М. Methods: differential thermal analysis, X-ray diffraction analysis, method of aluminium micropowders exposure with [gamma]-radiation, method of calculation of the activity parameters of aluminium powders. Results. Quantitative indicators of the reactivity of aluminium micropowders ASD-6 and ASD-6M before and after exposure with [gamma]-radiation were obtained. The radiation source was the Co{60} isotope with the energy of 1,17 and 1,33 MeV, i. e. the energy substantially below the threshold of photonuclear reactions. The doses to the powder samples exposure were 1, 2, 4, 8, and 10 Mrad. After [gamma]-radiation exposure the micropowders oxidation start temperature has maximally decreased on 90 and 85 °C; maximal oxidation rate increased by 83 and 36 %; the degree of oxidation (at heating up to 1250 °C) increased by 5,1 %, and minimally decreased by 1,3 % for the ASD-6 and the ASD-6M micropowders, accordingly. The specific thermal effect of oxidation after [gamma]-radiation exposure with all doses was greater than for non-exposed powders; the maximum values of the specific thermal effect was on 199,5 kJ/mol for ASD-6, and 134,8 kJ/mol for ASD6M higher than thermal effects for non-exposed powders, which significantly exceeds the standard heat of aluminium melting (10,8 kJ/mol). Consequently, such a state of the «aluminium - aluminium oxide» system is characterized by the stored energy, 9 times higher than the standard heat of aluminium melting, which is impossible according to thermodynamics. At the same time, it is known that energy is stored in nanopowders due to the formation of a double electric layer in aluminium particles.

Reduced graphene oxide (RGO) possesses unique thermal and optical properties. It could act as black body emitter with high-infrared emissivity. RGO could meet wide applications in advanced infrared...

Commonly, sparks emit light according to the well-known black (gray) body radiation. Recently, we reported on color‐changing sparks based on erbium powder, which switch their light emission between black body emission (surface combustion) and element‐specific emission (vapor phase combustion). Herein, we investigated the spark formation from the adjacent rare‐earth elements. The corresponding boiling points are significantly below (Yb, Sm, Tm) or above (Y, Lu) the boiling point of Er. While Yb and Sm evaporate too fast to form longer sparks, Y, Lu and Tm form color‐changing sparks with varying length of the element‐specific emission phase. The sparks were investigated by time‐resolved emission spectroscopy, long‐time exposures, and NIR/MIR imaging. The same basic pyrotechnic formulation containing one of these metal powders reveals a strongly differing burning behavior depending on the boiling point of the metal. The burning characteristics change from a green strobe (Yb) to intense colorful crackling (Tm) and finally a sparkling fountain with long‐flying sparks (Lu, Y, Er).

One of the most challenging tasks in the field of light‐producing pyrotechnics is the generation of saturated blue light with high spectral purity. Only copper salts in combination with chlorine seem to be high‐performing blue light emitters. However, in modern pyrotechnics the application of chlorine should be avoided. Different strategies are presented to further fine‐tune literature‐known chlorine‐free blue‐light‐emitting pyrotechnical compositions. The copper iodate as well as the copper bromate systems have been studied by using small amounts of nitrogen‐rich compounds like 1,2,4‐triazole, 5‐amino‐1H‐tetrazole or 3‐nitro‐1H‐1,2,4‐triazole. To overcome sensitivity issues, a two‐component epoxy binder system was introduced. The application of both copper(I) iodide and copper(I) bromide in the same pyrotechnical formulation were considered as blue‐light‐emitting species. Further, a quite new approach by using copper(I) nitrogen‐rich coordination compounds was investigated to give a blue flame color. All relevant formulations were characterized with respect to their dominant wavelength and spectral purity as well as impact and friction sensitivity.

In this paper, an ingenious strategy based on constructing energetic metal–organic frameworks (EMOFs) with cesium salts for new green and practical pyrotechnic composition is described. In order to obtain a non-hygroscopic, chlorine-free formulation, a novel triazole nitrogen-rich energetic ligand, N-(5′-amino-1H,1′H-[3,3′-bi(1,2,4-triazol)]-5-yl)nitramine (HABTNA), was designed and synthesized, which exhibited some good properties such as insensitivity, high nitrogen content and energy, and excellent oxygen balance. More importantly, using this triazole ligand and cesium(I) salts, an energetic metal–organic framework (EMOF) structure as a pyrotechnic colorant was built by a simple and green aqueous solution crystallization method. The results of single-crystal X-ray diffraction experiments indicated that this EMOF has a compact three-dimensional structure with high density. Physical and chemical property tests revealed that this Cs(I)-based MOF has excellent moisture resistance and thermal stability, while, at the same time, it was also proved to be a high-energy insensitive energetic material with energy up to the explosive level. By a systematic pyrotechnic performance experiment, a chlorine-free pyrotechnic formulation with this flammable EMOF as the main component was developed, which was the first orange-light-emitting pyrotechnic formulation with high color purity and intensity.

Research on novel energetic coordination polymers (ECPs) has become increasingly important for energetic materials; numerous ECPs have been reported and found to be potential energetic materials. In this study, 1,2,3-triazole-4,5-dicarboxylic acid was synthesized by an innovative synthetic route, and its complexes with alkali metals (Li, Na, K, Rb, Cs) were synthesized and comprehensively characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR and mass spectra. Most of the synthesized complexes exhibit excellent thermostability, with decomposition temperatures ranging from 312 to 334 °C, and they show good experimental densities. Additionally, the non-isothermal kinetic parameters and thermodynamic parameters were calculated for all prepared ECPs. The combustion flames of the five complexes are in a range of characteristic flame colors (from purple-red to blue). At the same time, all the synthesized CPs have remarkable insensitivity toward friction and impact (FS > 360 N, IS > 40 J), which makes them promising component candidates for chlorine-free “green” pyrotechnics.

Green low-sensitivity energetic materials which can be stored under laboratory conditions and do not ignite spontaneously at room temperature are currently of high relevance due to their multiple energy applications in propulsion, pyrotechnics or civil engineering. In this context, we report a gram-scale synthesis of copper oxide (Cu2O) nanoparticles interfaced at the surface of 2D aluminum (Al) nanosheets. This synthesis is mild, cheap, and environmentally friendly, allowing us to obtain a stable and homogeneous product with high crystallinity. The burst heat released was estimated to be 6841 ± 272 J g−1 under air, and 2946 ± 306 J g−1 under a nitrogen (N2) atmosphere, which are the largest values reported so far. We attribute this superior performance to the intimate interfacing between Al and Cu2O nanoparticles. The complex reactivity of this material was thoroughly studied, permitting to account for the branching of reactions occurring in the material under different conditions, which is essential for the understanding of the factors governing the reactivity.

Presented herein is a study on the ignition reaction kinetics and mechanism of B4C/KNO3 and B4C/KClO4 pyrotechnic smoke compositions using the non-isothermal thermogravimetry and differential scanning calorimetry techniques. The pyrotechnics in oxygen balance of − 10%, − 20% and − 30% were prepared for the experiments. The results of measurements showed that the pyrotechnics in oxygen balance of − 20% had the highest enthalpy. The activation energy (Ea) of ignition reactions was calculated by using Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS) methods. The Ea values of B4C/KNO3 and B4C/KClO4 were 139.5 and 214.6 kJ mol−1 calculated by OFW method, and 129.3 and 210.7 kJ mol−1 by KAS method. The differential and integral reaction mechanism functions of B4C/KNO3 and B4C/KClO4 were determined, respectively, by z(α) master plots method, f1(α) = 2(1 − α)[− ln(1 − α)]1/2, g1(α) = [− ln(1 − α)]1/2, and f2(α) = 3(1 − α)[− ln(1 − α)]2/3, g2(α) = [− ln(1 − α)]1/3. The pre-exponential factors, lnA = 11.6 and 22.3 min−1, were obtained by the intercept of KAS method for ignition reaction of B4C/KNO3 and B4C/KClO4 pyrotechnics. Based on the results, the burning rates, thermal sensitivities and application methods of B4C/KNO3 and B4C/KClO4 were predicted.

Until today, all blue‐colored light‐generating pyrotechnics are still based on copper and a halogen‐source providing the blue‐emitting species copper(I) chloride, copper(I) bromide or copper(I) iodide. The use of indium as a potential halogen‐free blue light emitter in modern pyrotechnics is described. Therefore, metallic indium was introduced as both fuel and colorant in various pyrotechnical formulations including guanidine nitrate or potassium nitrate as oxidizing agent as well as magnesium, hexamethylentetramine and 5‐amino‐1H‐tetrazole as fuel. The effect of incandescence was examined by applying different magnesium contents within the mixtures. Emission spectra and occurring emission lines of indium‐based pyrotechnical compositions were recorded and evaluated for the first time. Since the expected blue flame color could not be completely achieved, the emission of indium was discussed from an academic point of view.

In order to improve the shortcomings such as low ignition output energy of bridge wire pyrotechnics, poor anti-electromagnetic interference ability, and incompatibility with microelectronics manufacturing process, magnetron sputtering technology is used to integrate Nano Al/MoO 3 film into bridge wire igniter. There are 5 kinds of energetic bridge wire igniter BW-Al/MoO 3 , 20nm/30nm, 60nm/90nm, 75nm/75nm, 85nm/65nm, 120nm/180nm. The results of electric explosion experiments show that with the increase of excitation voltage, the critical ignition time and total action time of the energetic bridge wire are significantly reduced, and the critical ignition energy and total action energy are significantly increased; the Al/MoO 3 bridge wire with a modulation period of 50nm ignites. The ignition currents of 50% and 99.9% under constant current conditions are only 50mA and 90mA, and the ignition voltages of 50% and 99.9% under the conditions of capacitor discharge excitation are 2.30V and 2.56V respectively; the modulation period increases to 150nm and 300nm, both the current ignition sensitivity and the voltage ignition sensitivity show a significant upward trend; the Al/MoO 3 reactive thin film ignition device with the bridge wire as the transducer element can ignite the B/KNO 3 tablet when the ignition gap is 1mm. When the bridge wire without Al/MoO 3 film is in close contact with the B/KNO 3 tablet and the excitation voltage is 50V, the tablet cannot be ignited.

Rapid screening for chemical traces of explosives and narcotics is widely used to support homeland security and law enforcement. These target compounds span a range of physicochemical properties from organic to inorganic, with preferential ionization pathways in both negative and positive mode operation. Nonvolatile inorganic oxidizers present in homemade fuel-oxidizer mixtures, pyrotechnics, and propellants create a unique challenge to traditional thermal desorption-based technologies. Developments in solid–liquid extraction techniques, specifically, open port sampling interface mass spectrometry (OPSI-MS) provide compelling capabilities to address these hurdles. In this proof of concept study, we investigated the trace detection of wipe-based (i.e., common swipe sampling collection method) explosives, oxidizers, and narcotics using an OPSI source and compact single quadrupole mass analyzer. The liquid dissolution and extraction capabilities of OPSI enabled detection of both traditional military-grade explosives and homemade explosive oxidizers. OPSI-MS sensitivities to a series of seven target compounds from polytetrafluoroethylene (PTFE) coated fiberglass sampling wipes were on the order of several nanograms to sub-nanogram levels. Comparisons with direct solution-based sample analysis enabled quantification of wipe-based sample extraction effects. The system demonstrated quick temporal responses, polarity switching capabilities, and rapid signal decay with minimal carryover, all critical to high throughput screening applications. Coupling traditional swipe sampling with OPSI-MS offers a promising tool for contraband screening applications.

As the most important component for MEMS-based pyrotechnics, the micrometer should generate enough energy to successfully ignite the next explosive. An enhanced reactive igniter was designed and fabricated through sputtering the Al/CuO nanolaminates onto the NiCr micro-heater to enhance the output energy of the NiCr micro-heater. The average thickness of the Al/CuO nanolaminate is 6.84 [Formula: see text]m, and the designed thickness is 6 [Formula: see text]m. The grain sizes of Al/CuO nanolaminates are not uniform, and the particle grains of the Al/CuO nanolaminates at the top are smaller than those at the bottom. When the applied currents passed through the igniter, the resistance of the igniter changed dynamically, leading to the igniter experiencing three stages. Compared to the bare NiCr micro-heater without depositing Al/CuO nanolaminates, the enhanced reactive igniter can successfully ignite Zr/KClO4 explosive, indicating that the Al/CuO nanolaminates could enhance the output capability of the NiCr micro-heater. It is of vital importance to guide the design of MEMS-based pyrotechnics.

V diplomskem delu so zajete informacije o uporabi pirotehnike. Cilj diplomskega dela je prikazati, kako živali doživljajo uporabo pirotehničnih izdelkov. Osredotočili smo se na mačke, pse, ptice in govedo. Živali imajo namreč bolj občutljiva čutila od ljudi, zato pokanje in eksplozije doživljajo veliko bolj intenzivno kot ljudje. V diplomskem delu smo opisali čutila (vid in sluh) in hormonski (endokrini) sistem pri živalih. Dodali smo tudi priporočila o tem, kako lahko živalim pomagamo v stresnem obdobju praznovanja novega leta (npr. uporaba feromonov). Ravno v tem obdobju veliko število živali pobegne in se izgubi, druge doživljajo močan stres, ki negativno vpliva na njihovo psihično in fizično stanje. Diplomsko delo smo napisali po metodi pregleda literature, z zbiranjem podatkov s pomočjo knjig, internetnih brskalnikov in strokovnih revij. Ugotovili smo, da so živali zaradi hrupa in izraženega strahu pred pirotehničnimi zvoki pod stresom, zaradi česar se jim zviša raven stresnega hormona kortizola v krvi, ki v previsokih koncentracijah lahko povzroča zdravstvene težave, kot so samopoškodovanje, padec prireje, bolezni in drugo. Trenutno so v veljavi nekatera priporočila, kako lahko zmanjšamo negativne posledice pirotehnike, in sicer z zgodnjo socializacijo živali, učenjem na neprijetne zvoke, z uporabo feromonov, uporabo širokega povoja ali traku in s prilagoditvijo okolja, ki je za živali bolj prijazno in zagotavlja udobje. The BSc thesis contains information about the use of pyrotechnics. The aim of the thesis was to show how it affects animals. We focused on cats, dogs, birds and cattle. Animals have more sensitive senses than humans, so they experience the bangs and explosions much more intensely. In the thesis, we described the animal senses (vision and hearing) and the hormonal (endocrine) system in animals. We also gave recommendations on how to help animals during the stressful time of New Year's Eve celebrations (e.g., use of pheromones). At this time of the year, many animals run away or get lost some of them experience a lot of stress, which negatively affects on their psychological and physiological state. The thesis was written using a literature review method, by collecting data from books, the internet, and journals. The findings show that the animals are under great stress due to the noise and fear caused by the sound of pyrotechnics, which is why the level of cortisol in their blood increases. In very high concentrations, it can lead to health problems such as selfinjury, decreased performance, illness, and more. Currently, there are some recommendations to reduce the negative effects, such as early socialisation, desensitisation (learning to accept certain stimuli – in our case, sounds), use of pheromones, thunder shirts (wrapping the animal with a wide bandage or wrap) and adapting the environment to make it more suitable, safe and comfortable for the animal.

The chemical analysis of homemade explosives (HMEs) and improvised explosive devices (IEDs) remains challenging for fieldable analytical instrumentation and sensors. Complex explosive fuel-oxidizer mixtures, black and smokeless powders, flash powders, and pyrotechnics often include an array of potential organic and inorganic components that present unique interference and matrix effect difficulties. The widely varying physicochemical properties of these components as well as external environmental interferents and background challenge many sampling and sensing modalities. This review provides perspective on these emerging challenges, critically discusses developments in sampling, sensors, and instrumentation, and showcases advancements for the trace detection of inorganic-based explosives.

The MEMS detonated device is the new generation of pyrotechnics, the safety of which influence the whole munition system, so the device is only controlled by single electro signal is unreliable. In order to solve the difficulties, a MEMS detonated device with built-in safety and arming device is proposed in this paper. The device is composed of the detonator, the safety and arming device (SAD), the cover plate and the PCB. The detonator is a NiCr alloy bridge foil with Al/CuO energetic composite film. The SAD is set on the top of the detonator to add a mechanical insurance. With 11V driven voltages of electro-thermal actuators, the SAD can realize the bidirectional large-displacement movement of the barrier, which can reciprocally switch the device condition between safety condition and arming condition. The SAD has a Silicon/Ni enhanced barrier. In safety condition, it can block the flame which the detonator under 64V voltage stimulating generate. And the flame can go through barrier in arming condition.

The research article aims to study the impact and thermal sensitivity of pyrotechnic compositions which contain potassium perchlorate (KClO4), aluminium (Al) and graphite (C). Simultaneous DSC-TGA (Differential Scanning Calorimetry and Thermogravimetric Analysis) were used for studying the thermal sensitivity, and BAM fall hammer was used for studying the impact sensitivity. The onset temperature of the exothermic reaction is between 521°C to 528°C for all the studied compositions. The lowest onset temperature of 521°C and limiting impact energy of 16.67 J were found for the composition containing 64% of potassium perchlorate (KClO4), 33% aluminium (Al) and 3% graphite (C). The highest exothermic energy of 936 J/g was released for pyrotechnic composition consisting of 72% potassium perchlorate (KClO4), 25% aluminium (Al) and 3% graphite (C), which is close to the exothermic energy release of 910 J/g for pyrotechnic composition consisting 64% potassium perchlorate (KClO4), 33% aluminium (Al) and 3% graphite (C). Potassium chloride (KCl) was generated after the exothermic reaction, which was confirmed from the endothermic peak at around 773°C.

Various jet injectors have been developed and used for the effective and efficient administration of drugs. Jet injections overcome the limitations of other drug delivery methods, such as ablation, iontophoresis, electroporation, sonophoresis, and microneedles, because jet injection is not limited by the diffusion rates of different drugs. However, controlling the jet pressure during drug delivery is difficult with most conventional jet injectors. Efficacy evaluation of such devices on laboratory animals is strongly required before initiating human clinical trials, but minimal research has been performed for the device developments. Therefore, we developed jet injector devices based on pyrotechnics using 2 types of explosives with different burning rates; we call these pyro-drive jet injectors. The liquid jet pressure profile suggests that the penetration depth and injection volume for soft materials and skin tissue are controllable. Here, we propose the pyro-drive jet injectors as another candidate well-controlled jet injector for laboratory animals in drug discovery testing as well as human clinical use.

Thermite reactions between metal fuels and oxide oxidizers are highly exothermic and self-sustaining, so they find wide applications in the explosion, pyrotechnics, thermal batteries, micro-actuator, and material synthesis and process. Compared to the well-studied aluminum (Al)-based thermites, boron (B)-based thermites are thermodynamically attractive due to boron's higher volumetric and gravimetric energy densities and they received limited attention. Previous studies have compared the effect of metal oxide on the reaction onset temperature of B-based thermites and identified that B/Bi2O3 and B/CuO thermites have lower reaction onset temperatures than other B/metal oxides. Nevertheless, there is no systematic study on the effect of metal oxide on both ignition and combustion of B-based thermite. In addition, no study has investigated the effect of binary metal oxide mixtures for B-based thermite. Herein, we experimentally tested five common metal oxides (CuO, Bi2O3, MoO3, Co3O4, and Fe2O3) on the ignition and combustion characteristics of sub-micron sized B particles using Xenon flash ignition, constant-volume pressure vessel and bomb calorimeter experiments. We observed that Bi2O3 and CuO are the most effective oxidizer for ignition and combustion of boron, respectively. We further identified that the binary oxide mixture (75 wt% B–CuO + 25 wt% B–Bi2O3) is more effective than all the single metal oxide for the ignition and combustion of boron particles. The results suggest that mixed oxides are potentially beneficial for ignition and combustion of other metal fuels as well.

Pyrotechnic compositions containing magnesium (Mg) powder face the problem of degradation by moisture. Although potassium dichromate is an effective stabilizer that avoids Mg degradation, it is detrimental for human health and environment. This study is aimed at developing a harmless stabilizer for Mg in pyrotechnics. We investigated the effect of magnesium stearate (MgSt) coating on stabilization and combustion properties of the coated Mg. The stabilization effect of MgSt coating was measured by aging test of ammonium perchlorate (AP) and Mg mixture (AP/Mg). The aging test revealed that MgSt coating reduced the generation of degradation product, Mg(OH)2. Results of burning test showed that MgSt has little effect on flame color, while it considerably decreased the burning rate. The influence of MgSt coating was lower than that of MgSt that was simply mixed with AP/Mg., This is the pre-peer reviewed version of the following article: Y. Nishiwaki, T. Matsunaga, M. Kumasaki, Prop., Explos., Pyrotech. 2019, 44, 1028., which has been published in final form at [https://doi.org/10.1002/prep.201800372]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

Thermal batteries are unique direct current (DC) electrical power sources with long shelf live, high reliability and higher power density than classical alkaline batteries. This paper gives a brief overview into the working principle of thermal batteries and reviews the properties of zirconium/barium chromate (Zr/BaCrO4) pyrolant previously used as first fire and iron/potassium perchlorate (Fe/KClO4) pyrolant (Heat), commonly applied as heating pellet in thermal batteries and its hazard properties. The review gives 64 references to the public domain. CAS-Nos. Zr: [7440-67-7], BaCrO4: [10294-40-3], Fe: [7439-89-6], KClO4: [7778-74-7], Viton: [9011-17-0].CAS-Nos. Zr: [7440-67-7], BaCrO4: [10294-40-3], Fe: [7439-89-6], KClO4: [7778-74-7], Viton: [9011-17-0]. Keywords: Barium chromate, Heat-powder, Iron, Lithium, Molten salt, Potassium perchlorate, Pyrotechnics, Thermal battery, Zirconium

As infrared seeking technology evolves, threats are better able to distinguish defensive infrared (IR) flares from true targets. Spectrally matched flares, which generally employ carbon-based fuels, are better able to decoy some advanced missiles by more closely mimicking the IR emission of the target. Cubane is a high-energy carbon-based scaffold which may be suitable for use as a fuel in spectrally matched flares. The enthalpy of formation and strain energy of a series of cubanes was predicted in silico, and their thermal and impact stability examined. All were found to undergo highly exothermic decomposition in sealed cell differential scanning calorimetry, and two cubanes subsequently underwent quantitative sensitiveness testing. Despite their F of I values being in the secondary explosive range, cubane-1,4-dicarboxylic acid (F of I=70) and 4-carbamoylcubane-1-carboxylic acid (F of I=90) were identified as potentially useful fuels for pyrotechnic infrared countermeasure flare formulations.

The large heat release predicted in the early investigations of energetic aluminum nanoparticles (Al NPs) used in solid-state propulsion and pyrotechnics has been offset by hindered diffusion-limited detonation rates due to excess oxide shell formations and surface area loss from aggregations. We address these challenges by manufacturing graphitic shell coated Al NPs (

Magnesium powder is a common fuel in the field of pyrotechnics. The metal corrodes easily under wet conditions. This can lead to problems such as spontaneous ignition and deterioration of combustion performance when the powder is used in humid areas. For pyrotechnic compositions containing magnesium, harmful stabilizers are often used. In this study, we researched a less harmful replacement for the stabilizer and selected linseed oil, which is used as cooking oil. Experiments were conducted to examine linseed oil’s stabilization effects against magnesium corrosion when it is in contact with an oxidizer under humid conditions by coating magnesium powder and soaking it in aqueous oxidizer solutions. The oxidation of linseed oil led to its polymerization, because of which the stabilizing effect of linseed oil was lost. Stearic acid, which is a saturated fatty acid, was also examined for its stabilizing effects. Melted stearic acid was mixed with magnesium, and coating of stearic acid on magnesium particles was confirmed. The effect of stearic acid coating is more prominent than that of simple mixing of stearic acid with Mg. The stabilization effect of linseed oil and stearic acid coating shows that unharmful organic stabilizers can also be used in pyrotechnic compositions containing Mg., This is a post-peer-review, pre-copyedit version of an article published in "Journal of Thermal Analysis and Calorimetry". The final authenticated version is available online at: http://dx.doi.org/10.1007/s10973-019-08069-z

Fluorine containing oxidizers, primarily polymers, are extensively used in pyrotechnic compositions. Fluorinated oxidizers are less explored for metalized propellants and explosives despite a potential advantage of substantial heat release combined with gaseous combustion products. This review summarizes different types of fluorinated oxidizers used in energetic formulations or of potential interest for such systems, including gases, polymers, and inorganic compounds. Types of energetic formulations employing metals and fluoropolymers are discussed in more detail, including methods used to prepare composites and resulting salient features of the obtained materials. Laboratory experiments characterizing such materials, in particular, electron microscopy and thermal analysis, are discussed, showing characteristic morphologies and reaction sequences observed in different metal-fluorinated oxidizer composites. Striking similarities are noted in reaction sequences for diverse compositions hinting at possible similarities in the respective reaction mechanisms. Experiments probing ignition and combustion of metal-fluorinated oxidizer composites in laboratory conditions are also reviewed, including impact, flash heating and shock ignition. Finally, some practical performance tests for energetic formulations are described following by a brief discussion of the reaction mechanisms expected to govern ignition and combustion in various metal-fluorinated oxidizer composites. The conclusions are combined with recommendation for future research in the area of reactive metal-fluorinated oxidizer composites. Keywords: Reactive materials, Composites, Redox reactions, Pyrotechnics, Propellants, Explosives

This study reports an experimental investigation into the chemical kinetics of several commercial pyrotechnic compositions. Differential Scanning Calorimetry (DSC) was utilized to elucidate the thermo-kinetic characteristics of four multicomponent pyrotechnic compositions. The combustion process of typical pyrotechnics is primarily driven by condensed phase reactions including processes such as phase change, decomposition, and oxidation. The multicomponent nature of practical pyrotechnics results in a particularly complex interaction between the components when heated. A thermo-kinetic study was performed to simulate the heating experienced by the pyrotechnics before the combustion zone. The physical processes occurring within these temperature limits provide important insight into the overall combustion rate. The non-isothermal DSC experimental technique combined with isoconversional methods, such as Friedman and Starink methods were utilized to evaluate the apparent chemical kinetics parameters for these propellants. The observations from the DSC study and isoconversional kinetic analysis provided an insight into the phenomenology of the combustion process of pyrotechnics. The problem of highly variable activation energy due to the presence of multiple reactions was addressed through a mechanistic deconvolution using nonlinear regression technique. The study confirmed the prominence of oxidizer decomposition on overall combustion reaction kinetics.

The combustion performance of metal particles for explosives, propellants, pyrotechnics, and bio-agent defeat can be optimized by controlling the chemistry, size, and coatings of the particles. Many pure and composite metal fuels used in these applications have been observed to microexplode during combustion. This causes particles to fragment, revealing fresh surfaces, which may enhance burn rates and efficiencies. Despite these potential benefits, few have attempted to control the bubbling and the microexplosion of metal powders as they combust in molten states. Here, we choose Al:Zr composite powders as a representative system to study bubbling and microexplosions and to identify active mechanisms. Using synchrotron x-rays and phase contrast imaging, we observe molten metal particles of various sizes as they burn in air at temperatures ranging from 2700 to 3500 K. We characterize bubble nucleation and growth in the interior of the particles during the combustion process, and we identify heterogeneous nucleation, slow growth and coalescence of bubbles, as well as rapid bubble growth leading to microexplosions. Bubble growth rates and Laplace pressures are calculated, and we find that during slow expansion growth rates are similar to classical predictions of bubble growth in superheated liquids. For rapid expansions we find that a critical growth rate of ∼0.5 m s−1, independent of the initial particle size, is necessary to enable microexplosions. We calculate the rate of gas generation that is needed to enable this growth and we conclude that nitrogen is the gas most likely driving rapid bubble growth and fragmentation. These results provide the first in situ observations of the mechanisms that control bubbling and microexplosions during the combustion of metal particles.