Yu Zhongshen, Fang Xiang, Li Yuchun, Wu Jiaxiang, Wu Shuangzhang, Zhang Jun, Ren Junkai, Zhong Mingshou, Chen Liping, Yao Miao
College of Field Engineering, PLA Army Engineering University, Nanjing 210007, China.
School of Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, China.
Materials (Basel). 2018 Oct 17;11(10):2008. doi: 10.3390/ma11102008.
As a novel energetic material with quite a high energy density, titanium hydride (TiH₂) was introduced into a polytetrafluoroethylene/aluminum (PTFE/Al) reactive material system for the first time. The effects of TiH₂ on the reaction energy, dynamic mechanical responses, and reaction properties of the composites were investigated through adiabatic bomb calorimeter, split-Hopkinson pressure bar, and drop-weight experiments. The results show that the reaction heat of the composites improved significantly as the content of TiH₂ increased. Under dynamic compression, these composites show obvious strain hardening and strain rate hardening effects. Besides, a certain amount of TiH₂ granules helps to improve the material's compressive strength, and the maximum would even reach 173.2 MPa with 5% TiH₂ percentage, 10.1% higher than that of PTFE/Al. Mesoscale images of the samples after dynamic compression indicate that interface debonding between the particles and PTFE matrix and the fracture of the PTFE matrix are the two major mechanisms resulting in the material's failure. In addition, the drop-weight experiments indicate that the material's impact sensitivities are sensitive to the content of TiH₂, which would be increased to within 20% of the content of TiH₂ compared with PTFE/Al, and the reaction degree is also improved to within 10% of the content of TiH₂. The retrieved reaction residues after drop-weight experiments imply that the reaction is initiated at the edges of the samples, indicating a shear-induced initiation mechanism of this kind of reactive material.
作为一种具有相当高能量密度的新型含能材料，氢化钛（TiH₂）首次被引入聚四氟乙烯/铝（PTFE/Al）反应材料体系。通过绝热量热计、分离式霍普金森压杆和落锤实验研究了TiH₂对复合材料反应能量、动态力学响应和反应性能的影响。结果表明，随着TiH₂含量的增加，复合材料的反应热显著提高。在动态压缩下，这些复合材料表现出明显的应变硬化和应变率硬化效应。此外，一定量的TiH₂颗粒有助于提高材料的抗压强度，当TiH₂含量为5%时，抗压强度最大值甚至可达173.2 MPa，比PTFE/Al高10.1%。动态压缩后样品的细观图像表明，颗粒与PTFE基体之间的界面脱粘和PTFE基体的断裂是导致材料失效的两个主要机制。此外，落锤实验表明，材料的冲击感度对TiH₂含量敏感，与PTFE/Al相比，当TiH₂含量增加到20%以内时，反应程度也提高到TiH₂含量的10%以内。落锤实验后回收的反应残渣表明反应在样品边缘开始，表明这种反应材料的剪切诱导引发机制。
