Additive manufacturing of multidimensional Al/PVDF-based energetic composite structures featuring enhanced safety and combustion performance

[Display omitted] •Additive manufacturing for assembling multidimensional structures composed of energetic materials.•Multidimensional fabrication and safe application of Al/PVDF energetic composite structures (ECSs)•Combustion performance of the Al/PVDF-based multidimensional ECSs evaluated.•The Al content in Al/PVDF ECSs controlled the propelling force in projectiles.•Potential applications in thermal engineering and defense industries. In this study, the formability and safe application of aluminum (Al)/polyvinylidene fluoride (PVDF) energetic composite-based multidimensional structures for initiating igniters and propelling small projectiles were systematically investigated. Specifically, Al/PVDF composite-based filaments were produced using micro-sized Al particles as a fuel and PVDF as a strong oxidizer and binder with various mixing ratios (i.e., Al:PVDF = 0:100 ∼ 60:40 in wt.%), and their combustion characteristics were examined. Consequently, stable ignition and continuous combustion were performed for the as-prepared Al/PVDF composites when the Al content was increased to >10 wt%. The burn rate of the Al/PVDF composite-based 3D-printed structures increased with the Al content (i.e., the resulting burn rate was 0 cm/s at Al:PVDF = 10:90 in wt.% and ∼7 cm/s at Al:PVDF = 30:70 in wt.%, respectively.). However, the formation of Al/PVDF-based 3D-printed structures without significant defects and exfoliation frequently failed when the Al content exceeded 30 wt.% in the Al/PVDF composites because of a lack of the PVDF binder. After optimizing the formability and combustion of the Al/PVDF-based 3D structures, we assembled 3D hollow cylindrical propellants for bullet-type projectiles. Finally, the control of the propelling force for small projectiles was successfully demonstrated by tuning the Al content in Al/PVDF composite-based 3D propellants propellants (i.e., the resulting average speed of bullet-type projectile was 0 m/s at Al:PVDF = 15:85 in wt.% and ∼7.5 m/s at Al:PVDF = 30:70 in wt.%, respectively.). This suggests that the Al/PVDF energetic composite-based multidimensional structures can potentially be applied to various thermal engineering fields and defense industries as heat energy sources, igniters, explosives, and propellants.