制备梯度结构来提高HMX/Al复合材料的燃烧和压力输出性能

Preparation of Graded Structured HMX/Al to Enhance Combustion and Pressure Output Performance

含铝炸药因其高能量密度和压力输出而被广泛应用。为了调控和提高含铝炸药的二次燃烧反应和压力输出,以竹子的微观结构为灵感设计了具有分级结构的HMX/Al径向梯度药柱,使用3D打印技术制备了不同铝含量和不同铝颗粒尺寸的HMX/Al径向梯度结构药柱,研究了Al含量和粒径分布对HMX/Al梯度结构燃烧性能和压力输出的影响。结果表明,当HMX/n‐Al(160 nm)径向梯度结构按照从中心层向外层Al的质量分数分别为10%、20%和30%分布时,内层的燃烧反应和火焰传播速度比外层更快;其密闭空间内由于气体释放而获得的压力(2337.61 kPa)高于反向分布的梯度结构药柱。当HMX/Al径向梯度结构按照从中心层向外层Al粒径依次为10μm‐Al,5μm‐Al和n‐Al分布时,梯度结构药柱的燃烧过程比较缓慢,可以看到单独铝颗粒的燃烧现象。当中间层为n‐Al时,HMX/Al径向梯度结构具有最大的压力输出(1512.65 kPa),高于均相的HMX/Al药柱;当中间层为10μm‐Al时,获得了具有双重峰的压力输出。

Aluminized explosives have been widely applied due to their high energy density and pressure output.To further enhance the secondary combustion reaction and pressure output of aluminized explosives,graded structure is designed inspired by the microstructure of bamboo.In this work,the radially-graded structured HMX/Al(RGS-HMX/Al)cylinders with three layers containing different sizes and content of Al were prepared through 3D direct writing technology.The effects of Al distribution on combustion and pressure output properties of graded HMX/Al were fully studied.For the RGS-HMX/Al cylinder with Al content of 10%,20%,and 30%distributed from inner to outer layer,the combustion reaction and flame propagation of inner layer were faster than that of outer layer.And the pressure(2337.61 kPa)was higher than that of RGS-HMX/Al cylinder with Al content in the reverse distribution.For the RGS-HMX/Al cylinder containing Al of 10μm,5μm,and 160 nm distributed from inner to outer layer,a slow combustion process with sparse bright Al droplets was observed.Moreover,the highest peak pressure(1512.65 kPa)was obtained for the RGS-HMX/Al cylinders with nAl in the middle layer,which exhibited much higher pressure output than that homogeneous HMX/Al cylinder.More importantly,bimodal pressure was observed for the RGS-HMX/Al cylinders with Al of 10μm in the middle layer.