Investigation on reaction energy, mechanical behavior and impact insensitivity of W-PTFE-Al composites with different W percentage

Reaction energy, mechanical behavior, and impact initiation of three kinds of tungsten (W)-polytetrafluoroethylene (PTFE)-aluminum (Al) composites are investigated. The reaction energy results show that, the reaction energy of W-PTFE-Al composites in both oxygen and argon decreases with the mass ratio of W increased from 50% to 80%. Quasi-static compression results show that, the increased mass ratio of W has no obvious influence on the strength of W-PTFE-Al composites. However, the critical failure strain presents obviously decreasing tendency with the increased mass ratio of W. Dynamic compression results show that, the strength enhances with the increased W in W-PTFE-Al. The critical failure strain shows no obvious difference when the W content of W-PTFE-Al increases. Under impact condition, the deflagration time of all the three kinds of W-PTFE-Al composites lasts for about 500. μs. The insensitivity to impact loading shows an increasing tendency with the increased W mass ratio. During impact compressive deformation, the PTFE matrix is elongated in nano-fibers, thus significantly increases the reaction activity of W-PTFE-Al composites. The nano-fiber structure is necessary for the reaction of W-PTFE-Al composites. The formation of PTFE nano-fibers must undergo severe plastic deformation, which is responsible for the excellent insensitivity of W-PTFE-Al composites.