Microstructure of Energetic Particles Investigated by X‐ray Powder Diffraction

Abstract

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.

Differentiation of stabilized nitrocellulose during artificial aging: Spectroscopy methods coupled with principal component analysis

“…As it can be seen from Figure B,C, an increase in the intensity peak at 2θ = 12.5° is observed with the increase of aging time. This peak was considered by several authors as a superposing double peak, assigned to one part of the crystalline domain of NC . Unlike the NC/DPA and NC/MENA mixtures, the experimental diffractograms of unaged and aged NC/ANA mixtures (Figure D) show the absence of this characteristic peak, which confirm the existence of compatibility issue between NC and ANA .…”

“…The deconvolution of the diffractograms peaks of unaged samples (pure NC, NC + DPA, NC + MENA, and NC + ANA) is performed using Pearson VII function. This method is widely used and proven in the literature …”

Acceleration of δ- to β-HMX-D8 Phase Retransformation with D2O and Intergranular Strain Evolution in a HMX-Based Polymer-Bonded Explosive

“…Enhanced peak broadening of XRD patterns is found in HMX compared to other nitramines such as RDX because of twinning. 13,14 However, the mechanism of crystal fracture for the HMX-based polymer-bonded explosive (PBX) is still puzzling.…”

“…Mechanical tests revealed the twinning, cleavage, and defect structure of single-crystal HMX. , Microcosmic detection methods such as X-ray diffraction (XRD) were also applied to study the microstructure in HMX. Enhanced peak broadening of XRD patterns is found in HMX compared to other nitramines such as RDX because of twinning. , However, the mechanism of crystal fracture for the HMX-based polymer-bonded explosive (PBX) is still puzzling.…”

Microstructure of the HMX‐Based PBX KS32 after Mechanical Loading

“…crystals. The XRD investigations revealed that diffraction peak broadeningd ue to small crystal domains and/orl attice microstrain correlates with shock sensitivities, but also provided information on the microstructureo fa morphous and partial crystalline energetic materials [15,16]. In this contexti nvestigations weres tartedw ith the aim to show how the microstructure of HMX crystals in the high explosivec harge KS32 is affectedb ys hock-loading.…”