Formula Design And Charge Technology Of Small Critical Size Booster Based On Melt Casting

Taking 3,4-dinitrofurazanofuroxan(DNTF)/TNT as liquid carrier, Octogen(HMX) as solid explosives, Estane5703 and microcrystalline as auxiliary additives, we designed a small critical size of casting booster formula that can be applied to Explosive Circuit Channel considiering the energy, safety, detonation and charging performance. The micro injection charge process of melt cast explosive was simulated by the ProCAST software, and researched by experiment. The main contents were as follows:Firstly, the process of micro-injection charging technology of casting explosive was simulated by Procast software. It is found that the injection-time and the substrate temperature are the critical process parameters. Syringe is subjected to static pressure in the injection process. The value of static pressure was change with the rate of solid-liquid ratio. The higher the ratio is, the greater the pressure is. According to the results of simulation, we designed a micro-injection charging device for casting explosive, which is consisted of process. a thermostatic waterbath, a hydraulic presser, and a metal syringe. The micro-injection charging experiments show that it can charge the cast-explosives with 75- 94 oC melting point into grooves.Secondly, DNTF / TNT / HMX / Estane5703 / microcrystalline wax were selected as the formulation of small critical size melt-casting booster. The HMX particles were pre-treated by the method of spray fine, pneumatic spray and spray drying method. The particles were characterized by scanning electron microscopy(SEM) and X-ray diffraction(XRD). It is found that the spray fine method, the pneumatic spray fine method can effectively reduce the explosive particles size to 1μm. Moreover, the particles obtained by the spray drying method can reach the nanometer. The particles prepared by the first two methods present polyhedron or flat in shapehowever, the spherical particles were obtained in the last method.Thirdly, the energy performance, rheological properties, explosion performance and the safety performance of small critical size booster formula at different ratios were tested. The test rusults shows that: the microcrystalline wax can improve the changing performance in gooves, and it has the best effect at ratio of 2%; The content of DNTF in the formula should not more than 40wt%, otherwise, it cannot pass the shock safy tests regulalized in GJB2178A-2005. The final optimized formula is DNTF / TNT / HMX(microsphere) / Estane5703 / microcrystalline wax = 34.8 /38 /23.2 /2 / 2.Finally, the performance of the small critical size formula was tested. The results were as follows: The Characteristic Drop Heights of the pormula(H50) is 38.6 cm; it can pass the shock safy tests regulalized in GJB2178A-2005; and it can booster stablely in the size of 0.7 mm*0.7 mm-straight grooves and 0.8 mm*0.8 mm-900 corner grooves; The detonation velocity is 8328 m.s-1 when the charge density of booster pellets(6mm diameter) is 1.68 g/cm3, and the detonation velocity is 7812 m.s-1 when the charge density is 1.70 g/cm3 in liner groove.