Microstructure of energetic particles investigated by X-ray powder diffraction

Incorporation of improved particle qualities reduces the sensitivity of plastic bonded explosives. The mechanisms that cause this effect are far from being clear. Investigations were made using Powder X-ray Diffraction for the characterization of the microstructure of energetic cyclic nitramines Hexogen (RDX (C3H6N6O6)) and Octogen (HMX (C4H8N8O8)), respectively, including reduced sensitivity and conventional samples. The investigations show that qualities can be distinguished in terms of particle size and micro strain by means of powder X-ray diffraction. Problems originating from low absorbance or poor orientation statistics of coarse powders have been overcome using advanced measuring techniques. The results are so far interesting for practical applications, e.g., the investigation of slightly absorbing powders (e.g., pharmaceutics, cosmetics, explosives) or coarse crystalline powders by means of diffractometry. The investigations revealed that sensitivity of RDX correlates with crystallite size, where insensitive particles consist of larger and fewer crystallites than the conventional product. The HMX qualities were found to be micro strain and crystallite size driven.