Mechanical properties, impact initiation characteristics and energy release effect of Al/PTFE reactive materials enhanced by Fe particles
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China;
3. College of Materials Science and Engineering, Yantai Nanshan University, Yantai 265713, China;
4. College of Sciences, National University of Defense Technology, Changsha 410008, China)
2. State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China;
3. College of Materials Science and Engineering, Yantai Nanshan University, Yantai 265713, China;
4. College of Sciences, National University of Defense Technology, Changsha 410008, China)
Abstract: Aluminum/polytetrafluoroethylene (Al/PTFE) composites are a promising category of reactive structural materials. In order to improve the mechanical properties and reactivity, Fe particles were introduced into Al/PTFE. Quasi-static and dynamic compression tests for Al/PTFE/Fe reactive materials were conducted, and significant strain and strain rate hardening phenomena were observed. The compression strength of Al/PTFE with Fe content of 30 wt.% reached 191.8 MPa at the strain rate of 5000 s-1, increased by 39% compared to Al/PTFE. The oriented PTFE nano-fibers could effectively prevent the propagation of micro-cracks. The impact reaction processes under SHPB and drop-weight conditions were observed by high-speed photography technology, and the reactivity was qualitatively characterized by a newly-designed device. Based on the results of TG-DSC and XRD analyses, the reaction involving Al/PTFE and Al/Fe was clarified. The Johnson-Cook constitutive model was established and the model results agreed well with experimental data. Under impact loading, the reactivity was speculated to be the result of multiple actions.
Key words: reactive materials; Al/PTFE/Fe; mechanical behavior; energy release characteristics; impact initiation mechanism