W骨架/Zr基非晶合金复合材料破片冲击释能特性研究

Shock-induced Reaction Characteristics of the Porous W/Zr-based Metallic Glass Composite Fragment

摘要:

采用准密封箱冲击超压实验,研究了W骨架/Zr基非晶合金复合材料的在不同冲击速度下和靶板厚度下的冲击释能特性。并根据温度控制含能结构材料冲击诱发化学反应的热动力学理论,拟合了材料反应的表观活化能E_a和反应系数n,分析了材料的热化学反应特性。结果表明,材料冲击超压峰值与冲击速度正相关,其激发反应阈值为766m/左右,在相同速度下,有使破片靶后释能效率最大化的最优靶板厚度,但在8mm厚钢靶范围内,前板厚度对冲击释能特性影响不大。材料冲击激发化学反应的冲击压力阈值P_c=18.37GPa,对应的理论温度阈值T_c=3736.6K。材料反应效率随着冲击压力和击波温度的增加而增加,在40GPa冲击压力范围内,材料并未完全反应,其理论反应效率达到61.5%。

Abstract:

W/Zr based metallic glass composite is the novel generation of multifunctional energetic structural materials. The quasi-sealed chamber tests are applied in order to investigate the shock-induced reaction characteristics of porous W/Zr-based metallic glass composite at various impact velocities. The influences of the cover plate thickness on the overpressure are also tested. Thermochemical theory of temperature controlled shocked-induced chemical reactions is used to analyze the reaction characteristics of materials, as well as to identify the reaction parameters. The experimental and theoretical results show that the peak value of the quasi-static pressure and impact velocities of the fragments had positive correlation. The critical velocity to initiate the reaction is around 766 m/s. For certain velocity, there would be an optimal thickness of cover plate to maximize the overpressure behind the plate. However, the behind-plate overpressure effect is relatively mild while the cover plate thickness less than 8 mm. The critical shock pressure P_c to initiate the chemical reaction is 18.37 GPa. Relatively, the theoretical critical shock temperature T_c is calculated to be 3736.6 K. The theoretical results show that the reaction efficiency in the chamber are increased with increasing of shock pressure or temperature. The theoretical reaction efficiency reaches 61.5% when the shock pressure is 40 GPa. Therefore, the chemical reactions of the material are uncompleted in the experiments.