Combustion/decomposition characteristics of 3D-printed Al/CuO, Al/ Fe2O3, Al/Bi2O3 and Al/PTFE hollow filaments

In recent decades, the preparation of various metastable intermolecular composites (MICs) has been widely reported in pursuit of excellent reactivity and safety. However, there is still relatively little research on structural energetic materials (EMs) through 3D printing of MICs inks. In this work, the hollow filaments with different MICs formulas were prepared by 3D printing using a core-shell nozzle. The morphology, thermal decomposition and gas-generation performance of the filaments were characterized, and the different combustion stages of the filaments were analyzed. The results show that the hollow filaments exhibit shorter unsteady combustion time and significantly increased steady flame propagation rate compared with solid filaments. For the hollow filaments of Al/CuO/F2311 formula (15 wt % of F2311), the unsteady combustion time is as low as 0.65 ms, and the steady flame propagation rate reaches 206.936 g/s. Thermal analysis and constant-volume combustion tests show that Al/CuO/F2311 formula provides the lowest thermal decomposition onset temperature (288 degrees C) and the best gas-generation performance (peak pressure: 0.191 MPa, pressurization rate: 12.337 MPa/s) compared with other composites.

Automated summary

This study explores the preparation of structural energetic materials (EMs) through 3D printing of hollow filaments, showing that they exhibit shorter unsteady combustion time and increased steady flame propagation rate. The hollow filaments with Al/CuO/F2311 formula demonstrate the lowest thermal decomposition onset temperature and the best gas-generation performance compared to other composites.