摘要
为了研究温度作用下奥克托今(HMX)晶体的微结构演化和热安定性,使用原位变温X射线小角散射(SAXS)和广角散射(WAXS),对比研究了平均粒径为5μm和20μm两种HMX晶体颗粒的缺陷演化和相变行为。WAXS结果表明,HMX(5μm)的β→δ相变起始温度为194℃,比HMX(20μm)的相变起始温度高8℃。Guinier定理拟合分析表明,两种HMX晶体在150℃均开始生成微缺陷,其回转半径约为0.9 nm;随温度升高,微缺陷的体积分数增加,高温下生成的微缺陷在降温过程不会消失;HMX(20μm)的微缺陷含量高于HMX(5μm)。微缺陷的累积会导致HMX晶体内部生成微裂纹,甚至发生开裂。SAXS、WAXS和扫描电镜观测结果均表明HMX(5μm)具有更为优异的热安定性。讨论了微缺陷的生成机制,以及微缺陷对HMX感度的潜在影响。
The microstructure of HMX(Octogen)crystal particles with average sizes of 5 and 20μm was studied by in situ variable-temperature small-angle X-ray scattering(SAXS)and wide-angle X-ray scattering(WAXS).The WAXS results showed that the initialβ→δphase transition temperature of HMX(5μm)is 194℃,which is 8℃higher than that of the HMX(20μm).Guinier law modelling analysis of SAXS measurements revealed the presence of defects with gyration radii between 0.6~0.9 nm will occur in HMX when above 150℃.The volume ratio of the defects irreversibly increases with temperature.The number of defects in HMX(20μm)was found to be higher than that of HMX(5μm).SAXS,WAXS and scanning electron microscopy all indicate that the thermal stability of HMX(5μm)is better than that of HMX(20μm).Finally,the mechanism of defects formation and their effect on the structural integrity and sensitivity of HMX were discussed.
作者
石婧
刘佳辉
白亮飞
闫冠云
段晓惠
田强
SHI Jing;LIU Jia-hui;BAI Liang-fei;YAN Guan-yun;DUAN Xiao-hui;TIAN Qiang(State Key Laboratory of Environment‑Friendly Energy Materials,Southwest University of Science and Technology,Mianyang 621010,China;Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621999,China;Key Laboratory of Neutron Physics,Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621999,China;School of Materials Science and Technology,Southwest University of Science and Technology,Mianyang 621010,China)
出处
《含能材料》
EI
CAS
CSCD
北大核心
2020年第9期848-853,I0006,共7页
Chinese Journal of Energetic Materials
基金
国家自然科学基金资助(11775195,U1730244),西南科技大学博士基金资助(18zx7108)。
关键词
小角散射
广角散射
奥克托今(HMX)
缺陷
相变
small-angle scattering
wide-angle scattering
Octogen(HMX)
defect
phase transition
