Abstract
Polytetrafluoroethylene/aluminum/tungsten (PTFE/Al/W) reactive materials of three different component mass ratios (73.5/26.5/0, 68.8/24.2/7 and 63.6/22.4/14) were studied in this research. Different from the PTFE/Al/W composites published elsewhere, the materials in our research were fabricated under a much lower sintering temperature and for a much shorter duration to achieve a brittle property, which aims to provide more sufficient energy release upon impact. Quasi-static compression tests, dynamic compression tests at room and elevated temperatures, and drop weight tests were conducted to evaluate the mechanical and impact-induced initiation characteristics of the materials. The materials before and after compression tests were observed by a scanning electron microscope to relate the mesoscale structural characteristics to their macro properties. All the three types of materials fail at very low strains during both quasi-static and dynamic compression. The stress-strain curves for quasi-static tests show obvious deviations while that for the dynamic tests consist of only linear-elastic and failure stages typically. The materials were also found to exhibit thermal softening at elevated temperatures and were strain-rate sensitive during dynamic tests, which were compared using dynamic increase factors (DIFs). Drop-weight test results show that the impact-initiation sensitivity increases with the increase of W content due to the brittle mechanical property. The high-speed video sequences and recovered sample residues of the drop-weight tests show that the reaction is initiated at two opposite positions near the edges of the samples, where the shear force concentrates the most intensively, indicating a shear-induced initiation mechanism.
Highlights
Reactive materials, which are characterized by their exothermic and rapid energy release upon impact with a target or when they are impacted, have been of concern for decades
Polytetrafluoroethylene filled by aluminum and tungsten particles (PTFE/Al/W) is a typical granular reactive material which is formed by pressing or sintering uniformly mixed metal powders into the fluorine-rich matrix to achieve sufficient strength and insensitivity
The drop-weight apparatus is the most widely used among the many methods of conveying reproducible mechanical stimulus to quantify the impact sensitivities and reaction process of reactive materials, and which are able to meet the requirement of a relatively low loading strain rate
Summary
Reactive materials, which are characterized by their exothermic and rapid energy release upon impact with a target or when they are impacted, have been of concern for decades. The reactive materials are composed of two or more non-explosive solids and stay inert until subjected to sufficiently strong mechanical stimulus to undergo fast burning or explosion with release of a high amount of chemical energy in addition to their kinetic energy Due to these distinctive properties, the reactive materials are considered as potential choices for military applications [1]. More prominent the brittle property of the reactive material is, more sufficient fragmentation and chemical reaction would result For this purpose, PTFE/Al/W reactive materials of three different compositions, sintered under a much lower temperature to achieve brittle properties, were fabricated to study its mechanical and impact initiation response in this study. The drop-weight apparatus is the most widely used among the many methods of conveying reproducible mechanical stimulus to quantify the impact sensitivities and reaction process of reactive materials, and which are able to meet the requirement of a relatively low loading strain rate,. A standard drop-weight apparatus as described above, as well as a high-speed photography system, was used to study the sensitivity and impact-initiation process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
