В настоящей работе исследовано влияние радиационно-химической модификации энергоемких соединений с различными дозами ионизирующего излучения на характеристики термораспада, морфологию поверхности кристаллов и горения высокоэнергетических конденсированных систем (ВКС) на их основе. Объектами исследования являлись поли-N-аллилметил-5-винилтетразол (МПВТ-А), гексанитрогексаазаизовюрцитан (HNIW), октоген (НМХ) и ВКС на их основе. Образцы облучались потоком электронов на ускорителях У-12 и ИЛУ-6 (энергия электронов 2,4–3,1 МэВ; импульсный ток 100-328 мА; частота импульсов 2,5–200 Гц) дозами от 20 до 120 кГр.

Данная статья посвящена исследованию влияния пористости прессованных таблеток из сверхтонкого порошка алюминия (СТП Al). Определен механизм горения, протекающий в две стадии: первая, медленная, включающая в себя как «кольцевое» горение боковой поверхности, так и параллельное горение концентрическими слоями, вторая стадия объемная, сопровождающаяся резким самопроизвольным увеличением температуры горения и интенсивности свечения. Показано, что увеличение плотности упаковки СТП Al позволяет замедлить процесс окисления алюминия более чем в два раза. Это обусловлено снижением газопроницаемости таблетки и затруднением доступа воздуха вглубь образца. Повышение пористости материала позволяет регулировать процесс нитридообразования за счёт увеличения содержания азота в продуктах при фильтрационном механизме горения, что открывает возможности получения тугоплавких материалов. This article is devoted to the study of the effect of porosity of compressed tablets from ultrafine aluminum powder (STP Al). The combustion mechanism was determined, which proceeds in two stages: the first, slow, which includes both "ring" combustion of the side surface and parallel combustion with concentric layers, the second stage is volumetric, accompanied by a sharp spontaneous increase in the combustion temperature and glow intensity. It has been shown that an increase in the packing density of HFC Al makes it possible to slow down the process of aluminum oxidation by more than two times. This is due to a decrease in the gas permeability of the tablet and the difficulty of air access deep into the sample. An increase in the porosity of the material makes it possible to regulate the process of nitride formation by increasing the nitrogen content in the products during the filtration mechanism of combustion, which opens up the possibility of obtaining refractory materials.

Определены особенности горения энергетических композиций на основе инертного и активного горючих-связующих с нитратом аммония в диапазоне давлений до 10 Мпа. Представлен сравнительный анализ влияния наноразмерных порошков металлов на процесс горения композиций с различными наполнителями: октоген, нитрат аммония, CL-20. Показана эффективность нанопорошков металлов (Cu, Ni, Mo, Al, Zn) и неметалла (B) в качестве катализаторов горения. The features of combustion of energy compositions based on inert and active combustible binders with ammonium nitrate in the pressure range up to 10 MPa have been determined. A comparative analysis of the effect of nanosized metal powders on the combustion process of compositions with various fillers: HMX, ammonium nitrate, CL-20 is presented. The efficiency of metal (Cu, Ni, Mo, Al, Zn) and non-metal (B) nano powders as combustion catalysts is shown.

Определены формально-кинетические характеристики термораспада нитро-нитрозоаминов и их смесей с октогеном. Реакция разложения нитрозоаналогов октогена и нитро-нитрозопроизводных тетраазадекалина характеризуется меньшей энергией активации по сравнению с октогеном, и протекает с большей скоростью. Проведен анализ активационных параметров термораспада смесей, установлено активирующее влияние нитрозопроизводных тетраазадекалина на разложение октогена. The formal-kinetic characteristics of the thermal decomposition of nitro-nitrosoamines and their mixtures with HMX have been determined. The decomposition reaction of nitroso analogs of HMX and nitro-nitroso derivatives of tetraazadecalin is characterized by a lower activation energy compared to HMX, and proceeds at a higher rate. The analysis of the activation parameters of the thermal decomposition of the mixtures was carried out, the activating effect of the nitroso derivatives of tetraazadecalin on the decomposition of HMX was established.

The composition of condensed products resulting from the combustion of thermite mixtures (Al + Fe 2 O 3 ) in air is studied by precise methods. It is shown that during combustion, calcium is formed and stabilized in amounts of maximal 0.55 wt %, while is missing from reactants of 99.7 wt % purity. To explain this, it is hypothesized that a low-energy nuclear reaction takes place alongside the reactions of aluminum oxidation and nitridation, resulting in the formation of calcium (Kervran–Bolotov reaction).

The mechanism of whisker crystals formation process by aluminum aerogels burning was studied adapting for ceramic technology problems solution. The correlation of aluminum aerogels burning characteristics and the final combustion products structure was found. The burning temperature, air pressure and nitrogen concentration are significantly effect on the crystals growth mechanism. A wide variety of the crystal morphology in condensed combustion products was found depended on experimental condition.

The experimental results of combustion of aluminum nanopowder (ANP) in air and AlN crystals formation process were studied. The air pressure during the combustion process significantly affected the crystals growth mechanism. Crystals with the different morphology (whiskers, hexagonal crystals, rods) were found in the condensed combustion products. (C) 2010 Elsevier B.V. All rights reserved.

The experimental data on the aluminum nanopowders (nAl) combustion in oxidizing media (air, propellants AP/HTPB/Al/HMX and energetic compositions) assuming the phenomenon of nitrides formation with the high yield is generalizes. In the present work the nAl, produced by electrical explosion of wires, was studied. The temperature, burning rate and radiation were measured at combustion and the actual burning process was recorded by a video camera. Scanning electron microscopy (SEM), X­ray diffraction (XRD) and chemical analysis were performed on the both initial powders and final condensed products. It was experimentally proved that combustion process of aluminum nanoparticles was two staged independently of burning condition in nitrogen­contained media. The formation of nitrides in presence of molecular nitrogen is the determining stage in the particles combustion. A qualitative discussion is given on the kinetic limitation for AlN (AlON) oxidation due to rapid condensation and encapsulation of solid AlN (AlON).

The effect of small additives (1.25–5.00%) of ultrafine aluminum powders (UFAP) on the rheology and combustion of model four-component energetic condensed systems is studied. It is found that the addition of UFAP decreases the temperature of HMX decomposition. Small additives of UFAP increase the burning rate of model energetic condensed systems and decrease the exponent ν in the burning rate law without deteriorating the rheological characteristics of the model propellants.

This paper summarizes the results from studies of the effect of 17 additives on the process and products of ultrafine aluminum combustion in air. It is shown that the additives influence the temperature and duration of the combustion process and the structure of the end products, including the yield of aluminum nitride. The major factor determining the yield of aluminum nitride is the maximum temperature reached in combustion of mixtures of ultrafine aluminum powder with definite additives.

A new quantitative method of estimating the reactivity of aluminum superfine powders for energetic applications has been suggested. The method is based on differential thermal analysis-thermogravimetry (DTA-TG) data analysis in air as oxidizers for measurement first of four reactivity parameters (temperature of intensive oxidation onset, maximum rate of oxidation, degree of conversion of metallic aluminum, and specific heat release). After the comprehensive testing of the powders, the most reactive powder was identified. The special features of the oxidation process for the most reactive samples of aluminum superfine powder, obtained with a wires electrical explosion method, are explained and a theoretical mechanism for a new phenomenon, "pulsed oxidation" of superfine aluminum powder in air, is proposed.

An experimental study of the combustion of superfine aluminum powders (average particle diameter as ∼ 0.1 μm) in air is reported. The formation of aluminum nitride during the combustion of aluminum in air and the influence of combustion conditions on the structures and compositions of the final products are addressed. The experiments were conducted in static air at 1 atm. Superfine aluminum powders were produced by exploding an electrically heated wire. Such a superfine aluminum powder is stable in air, but once ignited can burn in a self-sustaining way due to its low bulk density (∼0.1 g/cm3) and low thermal conductivity. During combustion, the temperature and radiation were measured; also the burning was recorded by a video camera. Scanning electron microscopy, X-ray diffraction and chemical analysis were performed on both the initial powders and final products. It was found that the powders ignited by local heating and burned in a two-stage self-propagating regime. The products of the first stage consisted of unreacted aluminum (∼70 mass %) and amorphous oxides with traces of AlN. After the second stage, the AlN content exceeded 50% and the residual Al content decreased to ∼10%. A qualitative discussion is given of the kinetic limitations for the oxidation of AlN due to rapid condensation and encapsulation of gaseous AlN.

The paper studies the combustion of mixtures of commercial aluminum powders (ASD-1 and ASD-4) and ultrafine powders of Al and γ-Al2O3 in air. It is shown that the combustion of coarsely dispersed commercial powders is accompanied by binding of air nitrogen with formation of AlN and AlON. The combustion of mixtures proceeds in two stages with the possible formation of intermediate gaseous and liquid products. The processes of sintering and incomplete combustion play an important role in the combustion of mixtures of commercial powders and ultrafine powders of aluminum.