高强度CL⁃20/HTPE基微尺度传爆药的打印成型及性能表征

Inkjet Printing and Performance Characterization of CL⁃20/HTPE Based Microscale Booster with High Strength

为了研制出力学性能优异的微机电系统(MEMS)火工品用微尺度传爆药,以六硝基六氮杂异伍兹烷(CL‐20)为主体炸药,以端羟基聚醚(HTPE)/硝化纤维素(NC)为复合黏结体系,以乙酸乙酯为共溶剂,加入一定量的甲苯二异氰酸酯(TDI)设计出一种全溶式炸药油墨,利用喷墨打印技术实现了高精度装药成型,利用异氰酸根与羟基的交联反应实现了微装药力学性能增强。采用电子密度仪、扫描电子显微镜、差示扫描量热仪、X射线衍射仪、纳米压痕仪分别对打印样品的密度、微观形貌、热安定性、炸药晶型和力学性能进行了表征。结果表明,打印样品实测密度为1.70 g·cm^(-3),可达最大理论密度的88.54%,打印样品中CL‐20由ε晶型转变为β晶型,其热分解表观活化能为173.00 kJ·mol^(-1),比原料CL‐20提升了13.17 kJ·mol^(-1)。打印样品弹性模量可高达10.47 GPa,硬度为0.22 GPa,展现了良好的力学性能。喷墨打印装药具有良好的传爆能力,临界爆轰尺寸和爆速分别为1 mm×0.18 mm和8054 m·s^(-1)。

In order to develop a micro-scale booster for Micro Electro-Mechanical Systems(MEMS)pyrotechnics with excellent mechanical properties.A fully soluble explosive ink was designed with hexanitrohexaazaisowurtzitane(CL-20)as the main explosive,hydroxyl terminated polyether(HTPE)/nitrocellulose(NC)as the bonding system,ethyl acetate as the co-solvent,and a certain amount of toluene diisocyanate(TDI).Inkjet printing technology was used to achieve high-precision charge molding,and the cross-linking reaction of isocyanate and hydroxyl group was used to enhance the mechanical properties of micro charge.The density,micro morphology,thermal stability,crystal form and mechanical properties of the samples were characterized by electron densitometer,scanning electron microscope,differential scanning calorimeter,X-ray diffraction and nanoindenter.The results show that the density of the printed sample is 1.70 g·cm^(-3),which is 88.54%of the theoretical maximum density.The crystal form of CL-20 in the printed sample is determined byεtype change toβtype.The apparent activation energy of thermal decomposition is 173.00 kJ·mol^(-1),which is 13.17 kJ·mol^(-1)higher than that of the raw material CL-20.The nanoindentation test results show that the elastic modulus of the printed sample is 10.47 GPa and the hardness is 0.22 GPa,showing good mechanical properties.Inkjet printing charge has good detonation transmission ability,and the critical detonation size and detonation velocity are 1 mm×0.18 mm and 8054 m·s^(-1),respectively.