Shock response of pentaerythritol tetranitrate single crystals

TLDR

The shock response of pentaerythritol tetranitrate single crystals was examined over 3.4–19 GPa across four crystallographic orientations, using wedge tests, plane‑wave explosive and gas‑gun impact experiments, and spectroscopic imaging to measure Hugoniot, initiation sensitivities, and chemiluminescent signatures while analyzing steric hindrance during edge‑dislocation‑driven shear flow. Intermediate velocity transitions and a 4‑GPa sensitivity anomaly for 〈110〉 orientations were observed, supporting the hypothesis that shock‑initiation sensitivity depends on anisotropic plastic flow and slip ease.

Abstract

The shock response of single crystals of the explosive pentaerythritol tetranitrate was studied from 3.4 to 19 GPa. Four orientations, 〈110〉, 〈001〉, 〈101〉, and 〈100〉 were studied. The shock Hugoniot and shock initiation sensitivities were measured in wedge tests. Intermediate velocity transitions were noted. A sensitivity anomaly near 4 GPa was discovered for 〈110〉 orientations. Chemiluminescent phenomena associated with this anomaly were studied using framing photography and uv/visible spectroscopy. Both plane-wave explosive and gas-gun impact experiments were done. Analysis of the steric hindrance occurring during edge dislocation motion in the shear flow associated with shock-induced uniaxial strain was done. The results corroborate the hypothesis that the orientation dependence of shock initiation sensitivity is due to the anisotropy of plastic flow, that is, the relative ease of slip in different orientations.