Influence of particle size on the breaking of aluminum particle shells

Rupturing the alumina shell (shell-breaking) is a prerequisite for releasing energy from aluminum powder. Thermal stress overload in a high-temperature environment is an important factor in the rupture of the alumina shell. COMSOL Multiphysics was used to simulate and analyze the shell-breaking response of micron-scale aluminum particles with different particle sizes at 650 ℃ in vacuum. The simulation results show that the thermal stability time and shell-breaking response time of 10 μm-100 μm aluminum particles are 0.15 μs-11.44 μs and 0.08 μs-3.94 μs, respectively. They also reveal the direct causes of shell breaking for aluminum particles with different particle sizes. When the particle size is less than 80 μm, the shell-breaking response is a direct result of compressive stress overload. When the particle size is between 80 μm and 100 μm, the shell-breaking response is a direct result of tensile stress overload. This article provides useful guidance for research into the energy release of aluminum powder.     

RDX基含铝炸药在混凝土中爆炸的实验研究

为了研究含铝炸药在混凝土介质中的毁伤效果,对不同含铝量的3种炸药进行了70g药量小尺寸混凝土爆炸实验,重点研究了铝粉含量和炸药埋深对毁伤效应的影响,利用高速摄影机拍摄了混凝土靶毁伤过程。结果表明:炸药埋深对炸药的毁伤效果有着重要的影响,埋深为30cm时的毁伤效果要远大于10cm时,当炸药的埋深为10cm时含铝量为15%的炸药毁伤效果最佳;铝粉含量越高,火光面积越大,持续的时间越长。     

铝氧比对含铝炸药性能影响的数值模拟

为了研究铝氧比对含铝炸药在混凝土介质中爆炸性能的影响,采用数值模拟与实验相结合的方法,针对铝氧比分别为0、0.257、0.632的含铝炸药,利用AUTODYN有限元程序建立计算模型,计算了柱形装药在混凝土介质中的爆炸破坏过程,并且得到了在比例距离为2.5~10的范围内,3种含铝炸药爆炸形成的冲击波压力时程曲线。计算结果表明:冲击波峰值压力的衰减指数随炸药的铝氧比增大而减小,衰减指数分别为2.1、1.71、1.60;另外,当含铝炸药的铝氧比为0.257时比冲击波能最大。