Recent and Future Trends in Pyrotechnics

Similar to the effects of Alex addition in pyrotechnics and solid propellants, replacement of conventional micron-sized A1 powder by nanosized A1 powder (Alex) increases the detonation velocities and heats of detonation of TNT/A1 formulations. The increase of VOD is more pronounced in small diameter charges, close to the critical diameter. On the contrary, n-Al powder does not increase the VOD of aluminized PBXs based on inert binders. It is very interesting to observe that the VOD of PBXs based on an energetic binder decreases on substitution of micron-sized A1 by Alex [119, 120]. Reshetov and his coworkers [121] reported in the early 1980s that the addition of Alex enhanced VOD of RDX. More recently, an increase in both VOD as well as brisance was demonstrated for a number of TNT-based tritonal and H-6 formulations containing Alex. The improvements in VOD -200-300ms1 and brisance up to 27% were observed in a number of tritonal charges on replacement of conventional or micron-sized A1 by Alex [122]. 

The Chinese scientists [123] have reported the preparation of nanoscale RDX (-50 nm) and nanoscale HMX (=70 nm) by an impinging method [124]. Researchers from China have also reported preparation and characterization of n-NTO and their data indicate that it decomposes at a lower temperature and at the same time, it is less sensitive to impact compared with m-NTO. This property of n-NTO is likely to be of tremendous significance for insensitive munitions [125]. The preparation of n-RDX particles with a mean size (=110-120 rim) but narrow distribution has also been reported by a novel method known as rapid expansion of supercritical solution (RESS) [126]. 

Some recent and future trends in terms of new materials for pyrotechnic applications are as follows  

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