مجله تحقیق و توسعه مواد پرانرژی
سال شانزدهم شماره 1 (پیاپی 35، بهار و تابستان 1399)

Research in space thrusters has been one of the topics of interest to researchers in the world in recent years due to the need for satellites with high durability in orbit and controllability. If the propulsion system is not used in the structure of the satellite, after a short time, the life of the satellite will end due to the inability to attitude control and orbit adjustment. Therefore, the use propulsion system is inevitable. Among the thrusters used, the hydrazine catalytic thruster has a very favorable position. However, since hydrazine is carcinogenic, research is ongoing to replace the monopropellant. Finally, the liquid monopropellant based on ammonium dinitramide (ADN) has been introduced. Decomposition of liquid monopropellant requires a suitable catalyst to perform this process in the best possible way. In this article, a literature survey indicated that most catalysts used for the decomposition of liquid monopropellant based on ADN are copper, platinum, and copper-platinum supported on gamma-alumina dopped with lanthanum.

In this study, the synthesis, physicochemical properties and energetic performance of fused heterocycle based energetic materials with two or more rings are investigated. These compounds have been considered with a coplanar polycyclic structure, higher heats of formation (HOF) and ring-strain energy stored in the molecules. Good energetic performance, high thermal stability and low sensitivity toward destructive mechanical stimuli increase the safety of the synthesis, transfer, and storage of high- density energetic compounds. These properties make fused heterocyclic compounds a suitable alternative to conventional high-energetic materials for military and civilian applications Among the compounds studied, some of them have explosive performance comparable or higher than conventional explosives such as TNT, HMX, RDX or CL-20 and lower sensitivity to external stimuli. They are suitable candidate for replacement of conventional explosives. Because of their high specific impalse, some of them are suitable for use in high-performance propellant formulations. Also, the difference between melting point and decomposition temperature makes these fused heterocycles suitable as melt cast explosive.

In recent decades the improvement and optimization of the properties of energetic materials are one of the most important research fields. In this regard, cocrystalization is introduced as a molecular engineering method. There are several methods for the synthesis of new crystals or the so-called cocrystallization process, including slow solvent evaporation, solvent / antisolvent, dry spray, ultrasonic and sound wave resonance. The scale up of energetic cocrystals is an important challenge in this field. In recent years, several reports are published about the role of Resonance Acoustic Mixer (RAM mixer) to improve and scale up of the energetic cocrystals. For example, CL-20:HMX cocrystal is synthesized and characterized using small amount of solvents applying RAM mixer. This method has several advantages in the energetic materials processes, such as increasing safety, scale up, speed of mixing, uniformity and avoid damage to the crystal structure of the materials. Also, this method provides the possibility of mixing without any viscosity limitations. Researches are shown that RAM mixing method is a potential new substrate for co-crystallization processes.

Accumulation of stock ammonitions along with the high cost of traditional ammonition destruction methods and also enviromental consideration, caused to recovery and/or usage altering of useless ammonitions. Many efforts were conducted in order to reach this hope and sometimes were obtained to good results .Generally, the recovery and reusing of ammunition were classifying to sevral categories such as: recovery of energetic materials for example recovery Energetic thermoplastic elastomer( ETPE), recovery Energetic material from PBX and RDX from comp A, reuse of components for another explosive products (non-military applicationse.g. Commercial mining explosives, Explosive welding, Oil and gas industry), and reclaiming components for use as non-explosive products (e.g. fertilizer, animal feed and conversioninto chemicals raw materials). Moreover of reusing of energetic materials, Scrap metals of ammunition could be used again. In this paper, methods of Recovery and reusing of stock ammunition were investigated.

The most important objective in the drop weight tear test (DWTT) is obtaining the fracture energy. DWTT use in the military, steel and pipeline industries. By installing the proper equipment, the dynamic impact load can be measured in terms of the hammer displacement of the DWTT machine and it can calculate many parameters such as initiation energy, propagation and total fracture energy. For this purpose, numerical analysis by ABAQUS software was used to determine the proper location of the strain gauge on the hammer. Then, the strain gauge circuit (load-cell) was installed and calibrated using analytical and experimental methods. In order to use the circuit, the voltage must be converted to the load values. The analytical and experimental methods were used to obtain the desired coefficient. The two coefficient had an acceptable difference. In addition, in order to increase the accuracy and repeatability, other equipment such as guide and micro-swich were used in the DWTT machine. Experiments with the DWTT machine showed the repeatability of the results.

Chalcopyrite is an inorganic compound with the molecular formula CuFeS2. So far, this semiconductor material has been synthesized by using hydrothermal (solvothermal), thermal decomposition and microwave. The structure and size of synthesized samples are characterized by XRD, XPS, SEM and TEM. Electrochemical performance of the assembled Li/CuFeS2 batteries was characterized by cyclic voltammetry and discharging test. The solid electrolyte of this type of military battery is melted by pyrotechnic materials embedded in its interior, providing the required electrical current.in this paper chalcopyrite specification, syntesis methods, application and its performance were studied.

In this article, the history, different types applications, literature and common terms in the field of civil explosives and some special tests of this type of explosives and finally the hazards of working with these products have been studied. Modern commercial or civil explosives based on ammonium nitrate were developed during the 1950s. These products are widely used in mining, road construction, tunneling and other construction activities and play a major role in the economic growth of countries. Slurries, water-gels, emulsions, dynamites and ANFO are the currently being produced and consumed civil explosives. Special terms in the field of production, characterization, classification and consumption of civil explosives are common, including permissibility, water resistance, COD, pressure desensitization, incendivity, etc. The sensitivity and safety of civil explosives is different from that of military explosives. For this reason, accidents related to civil explosives are mainly due to the user's unfamiliarity with the properties of these compounds. The field of production and work with civil explosives requires a chemistry and engineering vision in order to research and develop these useful products without incident