Detonation synthesis of β-SiC using carbon condensate from RDX/TNT detonation

Direct detonation synthesis of β-SiC was demonstrated using an RDX/TNT explosive charge loaded with elemental silicon powder detonated in an argon environment. The carbon source for the SiC formation was condensed from the detonation of the high explosive composition. β-SiC production was observed in ex-situ analysis using X-ray diffraction and was confirmed through X-ray photoelectron spectroscopy and transmission electron microscopy imaging of characteristic stacking faults along the (111) zone axis. Hydrodynamic modeling was used to estimate temperature and pressure states as a function of time within the detonation product flow of the RDX/TNT explosive charge. Simulated detonation pressures were validated experimentally via the plate dent test with comparison to empirically predicted Chapman-Jouguet steady-state detonation pressures. A simulated phase diagram was established using Gibbs Free Energy minimization to evaluate the potential for SiC/Si₃N₄ production at the conditions observed in the detonation product flow. Experiments varying the ratio of nitrogen to carbon in the explosive composition to adjust phase production are also discussed.