晶体缺陷对CL-20/NQ共晶炸药性能影响的理论研究

为了研究晶体缺陷对六硝基六氮杂异伍兹烷(CL-20)/硝基胍(NQ)共晶炸药的稳定性、感度与爆轰性能的影响,建立了"完美"型与含有晶体缺陷(掺杂、空位与位错)的CL-20/NQ共晶炸药模型。采用分子动力学方法,预测了各种模型的性能,得到了不同模型的结合能、引发键键长分布、键连双原子作用能、内聚能密度及爆轰参数并进行了比较。结果表明,与"完美"型晶体相比,缺陷晶体的结合能减小幅度为4.29%～24.33%,表明分子之间的相互作用力减弱,炸药的稳定性降低。缺陷晶体的引发键键长增大幅度为0.78%～6.04%,而键连双原子作用能减小幅度为2.86%～20.03%,内聚能密度减小幅度为2.46%～12.72%,表明炸药的感度升高,安全性变差。由于晶体缺陷的影响,炸药的密度、爆速与爆压减小幅度分别为0.58%～7.57%、0.43%～5.99%、1.19%～15.31%,表明能量密度与威力减小。因此,晶体缺陷会对CL-20/NQ共晶炸药的稳定性、感度与能量特性产生不利影响,其中空位缺陷对炸药性能的影响更为显著。

Theoretical Investigation of the Effect of Crystal Defect on the Propertiesof CL-20/NQ Cocrystal Explosive

To research the effect of crystal defect on the stability, sensitivity and detonation performance of hexanitrohexaazaisowurtzitane(CL-20) /nitroguanidine(NQ)cocrystal explosive, the"perfect"and defective(adulteration, vacancy and dislocation)CL-20/NQ cocrystal explosive models were established. Molecular dynamics method was applied to predict the properties of various models. The binding energy, trigger bond length distribution, bonding diatomic interaction energy, cohesive energy density and detonation parameters of different models were got and compared. The results show that compared with the"perfect"crystal, the decreasing ampliture of binding energy of defective crystal is 4.29%-24.33%, indicating that the intermolecular interaction energy is weakened and the stability is decreased. The increasing ampliture of trigger bond length of defective crystal is 0.78%-6.04%, while the decreasing ampliture of bonding diatomic interaction energy is 2.86%-20.03% and the decreasing ampliture of cohesive energy density is 2.46%-12.72%, indicating that the sensitivity of explosive is increased and safety is worsened. Owing to the influence of crystal defect, the decreasing ampliture of density, detonation velocity and detonation pressure of explosive is 0.58%-7.57%, 0.43%-5.99%, and 1.19%-15.31%, respectively, indicating that the energy density and power are decreased. Therefore, crystal defect has a negative effect on the stability, sensitivity and energetic characteristics of CL-20/NQ cocrystal explosive, among them, the effect of vacancy defect on the performance of explosive is more significant.