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In this paper, an SF‐3 double‐base propellant was treated by a supercritical carbon dioxide foaming process. Effects of the pressure of supercritical carbon dioxide on the morphology, energy level, and ingredients of the foamed SF‐3 double‐base propellant and the detonation performance of a perfusion explosive with the foamed SF‐3 double‐base propellant were studied. Results show that, with the increase of the pressure, the number of pores in the foamed SF‐3 double‐base propellant gradually increased, and some of the pores were connected to form a small amount of cracks. In the foaming process, the pressure had a small effect on the energy of foamed SF‐3, and the formation of dense pores increased the volume of the sample. The dense pores acted as "hotspots" during the detonation process of the perfusion explosive, allowing the explosive to have better detonation performance, as compared with the perfusion explosive with unfoamed SF‐3 which could not detonate effectively. When the pressure of supercritical CO2 was 8 MPa, the perfusion explosive with foamed SF‐3 had a shock wave energy of 1.06 kJ g−1 and a detonation velocity of 6521 m s−1. When the pressure was 11 MPa, the detonation velocity and shock wave energy of the perfusion explosive were 2.9 % and 6.6 % respectively higher than those under the pressure of 8 MPa. Therefore, with the increase of pressure, the detonation velocity and the shock wave energy of the perfusion explosive with foamed SF‐3 were increased, proving that increasing the pressure can effectively improve the detonation performance of perfusion explosives with foamed SF‐3. [ABSTRACT FROM AUTHOR]

In order to study the effects of different additives on the energy release of an SF‐3 double‐base propellant system comprising a boron‐containing hydrogen‐storage‐alloy (Mg(BHx)y), curves of heat generation versus the temperature and curves of adiabatic decomposition temperature versus the time, of this system with copper oxide (CuO) or nanometer copper oxide (nano‐CuO) as the additive were obtained by a scanning calorimeter (Scanning) and a fast ‐adiabatic accelerating rate calorimeter (Fast‐ARC), respectively. Kinetic parameters, such as the apparent activation energy, the pre‐exponential factor, and the reaction order were calculated. The effects of these two additives on the thermal decomposition of the SF‐3 double‐base propellant system containing Mg(BHx)y were investigated. The results show that CuO used in an amount within a certain range (1∼2.5 % based on the SF‐3 content) can promote the thermal decomposition reaction. When the amount of nano‐CuO added exceeds a certain value (about 2 % based on the SF‐3 content, the thermal decomposition reaction will be significantly slowed down, and the hindrance to the reaction will not be obviously changed after more nano‐CuO is added. [ABSTRACT FROM AUTHOR]

The supercritical CO2 foaming process is a preferable way to treat deserted SF‐3 propellants and solves problems of environmental pollution and waste of resources related to conventional treatment methods, and this process is an environmentally friendly method. In this paper, the effect of process conditions, including the immersion time of deserted SF‐3 propellants in the supercritical CO2 fluid, on the appearance of SF‐3 propellants and detonation performance of the perfusion explosive made from SF‐3 propellants are mainly studied. The results show that the diameter of foamed SF‐3 propellants increases with the immersion time when the immersion time is less than 60 min. When the immersion time is 60 min, the performance of the perfusion explosive made from foamed SF‐3 propellants is the best. The highest detonation velocity is 6683 m s−1, and the corresponding shock wave energy is 1.02 kJ g−1. When the immersion time is more than 60 min, the detonation velocity and the shock wave energy of the perfusion explosive made from foamed SF‐3 propellants decreases with the increase of the immersion time. [ABSTRACT FROM AUTHOR]