Impact-initiation sensitivity of high-temperature ptfe-al-w reactive materials

Drop-weight tests were conducted to investigate the impact-initiation sensitivity of high-temperature PTFE-Al-W reactive materials. The test results show that the impact-initiation sensitivity of the materials more than doubles with increasing the sample temperature from 25 to 350^◦C. Com-bined with the impact-induced initiation process recorded by high-speed video and the difference between reacted and unreacted residues, the crack-induced initiation mechanism was revealed. The rapid propagation of crack provides a high-temperature and aerobic environment where Al reacts violently to PTFE, which induces the initiation. Moreover, the influence of sample temperature on the sensitivity was discussed and analyzed. The analysis results indicate that the sensitivity shows a temperature interval effect, and 127 and 327^◦C are the interval boundaries where the sensitivity changes significantly. The sensitivity may leaps at 127^◦C and increases more rapidly in the temperature interval from 127 to 327^◦C, but hardly changes after the temperature reaches 327^◦C.