Current Developments in Polymer-Based Reactive Materials for Thermite-for-Demise (T4D) Technology

Within the framework of the project THREAD (THermite REactions Assisting satellite Demise) funded by the European Innovation Council (EIC), the use of thermites is being investigated to facilitate the controlled disintegration of satellites, upon atmospheric re-entry after decommissioning. The concept consists in placing thermite charges in key locations of the space platform, acting as additional and localized heat sources, triggered by the atmospheric aero-thermal heating. This innovative approach, called thermite-for-demise (T4D) is part of the wider design-for-demise (D4D) engineering methodology. Mechanical consistency of the charges is vital for proper integration, efficient heat transfer, and predictable behavior. This work presents one of the development paths followed by the THREAD project, consisting in UV curable slurries containing a thermite powder based on Mg and SiO2. Solid reference shapes have been produced through 3D printing using vat polymerization, incrementing progressively the quantity of the energetic material, from 40% to 60% by mass. Samples have been characterized for their ignition temperature in air at high heating rates, thermal behavior in inert atmosphere at low heating rate, and production accuracy. Experiments demonstrated that samples are feasible, and that their reactivity is triggered in a temperature range of interest for T4D application. For this specific case, these studies identified the 50% thermite loading as the optimal one. Higher content caused production problems due to scarce layer adhesion, while lower fraction tends to cause sedimentation.