Additive Manufacturing of Energetic Materials

This abstract describes the methodology and objectives aimed at investigating the compatibility of ammonium perchlorate and aluminum (AP/Al) with Viton (VAPAL) for use in additive manufacturing. The project is comprised of two phases. Phase 1 involves a compatibility analysis of the materials, followed by the formulation and rheological analysis of the VAPAL and a mock mixture (substituting ammonium chloride for AP) to predict optimal printing parameters. Phase 2 uses a Filabot extruder to form filaments of both materials for use in a Fused Deposition Modeling (FDM) printer. The project also aims to plot the energetic performance of the material in relation to solids loading and/or binder selection.

Results: The procedure for suspending AP/Al in Viton was effective, with a theoretical maximum density of 99.01%. Furthermore, the results from both sensitivity testing and analysis showed that Viton is compatible with AP/Al as the stability of the product increased when compared to pure ammonium perchlorate. Additional results from a differential scanning calorimeter show that the decomposition of the product occurs at the same temperature as ammonium perchlorate indicating that no new compound was created, and our AP was intact in Viton. Lastly, samples taken along an extruded sample show density of AP/Al similar to the measured density of 99.01%, validating our filament extruding process. Further research will be done exploring the feasibility of the VAPAL (Viton-Al/AP product) within 3D printing. Challenges we expect with this next phase of research include how Viton will behave in the extruder head of a printer, how high definition we can print with this filament, safe operating protocols when printing with VAPAL, and the variance in burn rate and deflagration rate of printed VAPAL.