The effect of PTFE on the physical compatibility and mechanical performance of Al-MoO3 mechanically activated energetic composites

Physical compatibility and mechanical performance are important to mechanically activated energetic composites. Herein, in order to research the effect of polytetrafluoroethylene (PTFE) on the physical compatibility and mechanical performance of aluminum (Al)-molybdenum trioxide (MoO3) mechanically activated energetic composites, dissipative particle dynamics (DPD) was applied to calculate the miscibility among Al, MoO3 and PTFE. Then the binding energies of Al-MoO3 and Al-MoO3-PTFE were predicted via molecular dynamic simulation. The mechanical performance of Al-MoO3-PTFE with different proportion of PTFE was calculated. Finally, ball milling was carried out to prepare Al-MoO3 and Al-MoO3-PTFE mechanically activated energetic composites, and the micro-morphologies were also characterized. Results show that PTFE can significantly improve the miscibility of Al-MoO3. Phase separation of Al-MoO3-PTFE ternary composites does not occur as the mass fraction of PTFE greater than 20%. PTFE can be adsorbed stably on Al, Al2O3 and MoO3 simultaneously. The rigidity, hardness, yield strength and fracture strength of the composites decrease with the increase of PTFE content. However, the ductility of the system does not change significantly with the increase of PTFE content. The size homogeneity of the prepared Al-MoO3 mechanically activated energetic composites is poor, whose micro-morphology is sheet aggregates with a large number of MoO3 debris. The addition of PTFE reduces the number of MoO3 debris in the aggregate, enhances the smoothness of aggregates and improves the physical compatibility of the composites. The experimental results are in good agreement with the calculated ones.

Automated summary

The study investigated the impact of PTFE on the physical compatibility and mechanical performance of Al-MoO3 mechanically activated energetic composites. Results showed that PTFE significantly improves the compatibility of Al-MoO3, while decreasing rigidity and strength but not affecting ductility significantly.