An excellent synergy between CL-20 and nanothermites in flaming and propelling with high specific impulse and superior safety to electrostatic discharge

Abstract

Nanothermites possess much attentions relying on potential probability to the fields of the military and civilian. Whereas, the practical applications for nanothermites have been limited by the high electrostatic discharge (ESD) sensitivity and little gas generation, which is a pronounced problem in the microthruster particularly. In this work, the two typical nanothermites (Al/CuO and Al/MoO3, as Al/MXOY) were assembled with various contents of CL-20 to be defined Al/MXOY@CL-20. The characteristics of Al/MXOY@CL-20 were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The ignition properties of Al/MXOY@CL-20, such as burning rate, the unrestrained combustion, ignition temperature, delay time, pressurization and propulsion properties, were studied. In addition, the energy required for 50% ignition probability (E50) was applied to evaluating the sensitivity of Al/MXOY@CL-20 to ESD. Results revealed that the total heat release for Al/MXOY@CL-20 was increased on account of CL-20, and CL-20 facilitated the transformation of CuO to Cu2O. The burning rates decreased with the increase of CL-20, whereas the burning rate of Al/MoO3@10%CL-20 was little higher than that of Al/MoO3. Al/CuO@10%CL-20 and Al/MoO3@30%CL-20 exhibited superior performances respectively for the maximum flame area, the lowest ignition temperature, the highest pressurization rate and specific impulse. The particular significance was that CL-20 played a positive role for Al/MXOY@CL-20 on the safety to ESD. For instance, the E50 of Al/CuO@50%CL-20 was 163.84 mJ meanwhile Al/CuO of that was 0.24 mJ. In conclusion, in the light of the superior specific impulse and the excellent safety to ESD, Al/MXOY@CL-20 (especially Al/CuO@10%CL-20 and Al/MoO3@30%CL-20) would possess the remarkable application prospects for practice in the microthruster.