摘要:
为了提升活性材料的力学和爆轰性能,将短切钛纤维添加到Al/PTFE基体中制备出Al/PTFE环状活性材料,并与RDX药柱形成Al/PTFE-RDX组合装药。利用万能材料试验机和分离式霍普金森杆研究了不同钛纤维含量对环状活性材料力学行为的影响;采用自由场爆炸测试系统、球形爆炸容器测试系统并结合比色测温技术,深入研究了短切钛纤维含量对组合装药的准静态压力、冲击波参数和热毁伤效应的影响。力学性能测试结果表明,随着钛纤维含量的增加,Al/PTFE环状活性材料在静态压缩条件下的弹性模量、屈服强度、抗压强度等参数以及在高速撞击下的屈服强度和抗压强度均呈现先增加后减小的趋势,并且均在短切钛纤维含量为3%时达到最大值。爆炸性能实验结果表明,短切钛纤维能够显著改善Al/PTFE-RDX组合装药的爆炸性能,当其含量为3%时,爆炸冲击波超压、正相作用时间和正冲量达到峰值分别为37.68 kPa、695.34 µs和12.34 Pa·s;而当含量为5%时后燃效应最显著,其爆炸准静态压力、火球最高平均温度和火球持续时间达到最大值70.50 kPa、2782 K和1668.90 μs。固体爆炸产物分析表明,短切钛纤维通过改善Al/PTFE基体力学强度、延缓Al/PTFE环状活性材料碎裂时间且促进界面反应并参与高温化学反应,产生的协同作用和正反馈效应可以同时增强Al/PTFE活性材料的力学韧性与能量释放效率。
Abstract:
To improve the mechanical behaviors and explosion performance of the Al/PTFE reactive materials, short-cut titanium fibers were added to Al/PTFE annular reactive materials, and subsequently assembled with RDX explosive column to form a composite charge. The effects of different titanium fiber contents on the mechanical behaviors of the annular reactive materials were investigated using a universal material testing machine and a split Hopkinson pressure bar. The influence of short-cut titanium fiber contents on the quasi-static pressure, shock wave parameters and thermal damage effects of the composite charge was studied in depth by the free-field explosion test system and spherical explosion container test system combined with the colorimetric temperature measurement technology. The temperature field of explosion flame was reconstructed by the colorimetric temperature measurement method with a high-speed camera, which was based on the gray-body radiation theory. A tungsten lamp calibrated the measurement accuracy of the temperature mapping system, and the fitting relationship between the temperatures and the gray values of the high-speed images was derived to obtain the conversion coefficient. The test results of mechanical properties showed that with the increase of titanium fiber content, the elastic modulus, yield strength, compressive strength valus of Al/PTFE annular reactive materials under the static compression conditions, as well as the yield strength and compressive strength valus under the high-speed impact, all exhibited an initial increase and followed by a decrease, reaching the maximum values at 3% content. The experimental results of explosion performance showed that short-cut titanium fibers could significantly enhance the explosion performance of Al/PTFE-RDX composite charges. When the content of short-cut titanium fibers was 3%, the peak values of the explosion shock wave overpressure, positive phase duration and positive impulse were 37.68 kPa, 695.34 µs and 12.34 Pa·s, respectively.While with 5% content of short--cut titanium fibers, the afterburning effect was the most significant, and the maximum values of the explosion quasi-static pressure, average fireball temperature and fireball duration reached 70.50 kPa, 2782 K and 1668.90 µs, respectively. Analysis of solid explosion products indicated that short-cut titanium fibers could enhance the mechanical strength of the Al/PTFE matrix, delay the fragmentation time of the Al/PTFE annular reactive materials, promote the interfacial reactions, and participate in high-temperature chemical reactions, generating a synergistic effect and positive feedback to improve the mechanical toughness and energy release efficiency of the reactive materials.