Electrospray fabrication of CL-20 composite microspheres for high-energy EFIs: Microstructure modulation and performance optimization

The utilization of high-energy explosives in Explosive Foil Initiators (EFIs) holds paramount significance. In this study, CL-20 composite microspheres were successfully prepared by electrostatic spraying technology, demonstrating narrow size distribution and high sphericity at 5% binder content. The strategy of introducing NC in GAP and F2602 effectively improved the porosity, specific surface area and apparent activation energy of CL-20 microspheres, where the increased specific surface area contributed to the narrow pulse sensibility of CL-20 microspheres. Compared to raw CL-20, these microspheres exhibited markedly improved safety properties. Comparative analysis with the HNS-IV revealed that CL-20 microspheres, with GAP/NC binder, demonstrated the minimum firing voltage of 1.10 kV and the narrow pulse initiation energy of 0.121 J, which was close to that of HNS-IV (1.08 kV and 0.117 J). However, CL-20 microspheres exhibited significantly enhanced detonation performance and output energy. The application of CL-20 microspheres in EFIs promoted the EFIs' miniaturization development.