Interface Reaction in Core–Shell Boron–FeF 3 : Direct Observation of Gas Release and Oxide Removal during Combustion

Boron is a high-energy fuel, but its persistent B2O3 surface oxide shell suppresses ignition and combustion. Here, we present a promising strategy for improving the performance of boron-based nanoenergetics. FeF3·xH2O-coated boron nanoparticles (B@FeF3·xH2O) are synthesized with a one-pot method and incorporated into 3D-printed thermite composites. Thermogravimetric analysis and T-jump ignition testing show that the FeF3·xH2O coating reduces the onset temperature of boron oxidation by >70 °C, while the combustion regression rates of 3D-printed thermites increased by up to 55%. High-speed digital inline holography and color pyrometry capture the in-flight particle fragments leaving the flame front and observe…

• DT
  Defense Threat Reduction Agency
• AF
  Air Force Office of Scientific Research