TiH2含量对Al/PTFE动态力学性能和撞击感度的影响

Effects of TiH2 content on dynamic mechanical properties and impact sensitivity of Al/PTFE

采用混合压制烧结法制备了4种不同TiH2含量的铝/氢化钛/聚四氟乙烯(Al/TiH2/PTFE)试件,并基于分离式霍普金森杆和落锤冲击实验,对反应材料的动态压缩力学性能、撞击感度及反应特性进行了研究。实验结果表明,4种材料均存在应变硬化和应变率硬化效应,随加载应变率的提高,材料屈服强度和硬化模量增大。相同加载应变率下,材料屈服强度随TiH2含量的增加而增高,材料压缩强度则先增高后降低,TiH2质量分数为5%时材料压缩强度达到最大值166.4 MPa,比Al/PTFE强度提高6.8%。在一定含量范围内(小于5%),加入TiH2有助于提高Al/PTFE材料撞击感度和能量释放水平,而TiH2质量分数大于10%时,材料撞击感度和反应剧烈程度则逐渐降低。与Al/PTFE相比,含TiH2试件反应火光周围有明显的火星喷溅现象,且此现象TiH2含量越高越显著。

Four kinds of aluminum/titanium hydride/polytetrafluoroethylene(Al/TiH2/PTFE) samples with different TiH2 contents were prepared by the mixed/compression/sintering method. The dynamic compression mechanical properties, impact sensitivity and reaction characteristics of the reaction materials were studied based on the split Hopkinson pressure bar(SHPB) and drop-weight impact tests. The results indicate that the four materials all show strain hardening and strain rate hardening effects, and the yield strength and hardening modulus increase with the increasing of the strain rate. Under the same loading strain rate, the yield strength of the material increases with the increasing of TiH2 content, and the compressive strength of the material increases first and then decreases. When the mass fraction of TiH2 is 5%, the compressive strength of the material reaches the maximum value of 166.4 MPa, which is 6.8% higher than that of the Al/PTFE. Within a certain range of mass fraction(less than 5%), adding TiH2 helps to improve the impact sensitivity and energy release level of the Al/PTFE material, while the impact sensitivity and the reaction degree gradually decrease when the mass fraction of TiH2 exceeds 10%. Compared with the Al/PTFE, there are sparks spraying from the reaction region of the TiH2-contained specimens, and this phenomenon is more significant with the increasing of TiH2 content.