Nature of the Enhanced Self-Heating Ability of Imperfect Energetic Crystals Relative to Perfect Ones

Abstract

It is extensively deemed that the increased self-heating ability of defects relative to perfect crystals increases the sensitivity, or reduces the safety, of energetic materials. Nevertheless, the nature of such increased self-heating ability remains unclear. The present work provides insight into the origin of such ability by ReaxFF reactive molecular dynamics simulations on the thermal decay of perfect and twinned β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) under three typical heating conditions—constant-temperature, programmed, and adiabatic—that represent various rates of heat exchange between the HMX crystal and environment. As a result, it is found that the enhanced self-heating ability stemmed from the high internal energy of the molecules around the defects, and such ability is remarkably exhibited with low heat-exchange rates between the energetic materials EMs and environment. Adiabatic heating is an extreme to exhibit the most remarkable such ability, as the superiority of the high...