Investigation on Mechanical Properties and Reaction Characteristics of Al‐PTFE Composites with Different Al Particle Size

Abstract

Al-PTFE (aluminum-polytetrafluoroethylene) serves as one among the most promising reactive materials (RMs). In this work, six types of Al-PTFE composites with different Al particle sizes (i.e., 50 nm, 1∼2 μm, 6∼7 μm, 12∼14 μm, 22∼24 μm, and 32∼34 μm) were prepared, and quasistatic compression and drop weight tests were conducted to characterize the mechanical properties and reaction characteristics of Al-PTFE composites. e reaction phenomenon and stress-strain curves were recorded by a high-speed camera and universal testing machine. e microstructure of selected specimens was anatomized through adopting a scanning electron microscope (SEM) to correlate the mesoscale structural characteristics to their macroproperties. As the results indicated, in the case of quasistatic compression, the strength of the composites was decreased (the yield strength falling from 22.7 MPa to 13.6 MPa and the hardening modulus declining from 33.3 MPa to 25 MPa) with the increase of the Al particle size. e toughness rose firstly and subsequently decreased and peaked as 116.42 MJ/m 3 at 6∼7 μm. e reaction phenomenon occurred only in composites with the Al particle size less than 10 μm. In drop weight tests, six types of specimens were overall reacted. As the Al particle size rose, the ignition energy of the composites enhanced and the composites turned out to be more insensitive to reaction. In a lower strain rate range (10), Al-PTFE specimens take on different mechanical properties and reaction characteristics in the case of different strain rates. e formation of circumferential open cracks is deemed as a prerequisite for Al-PTFE specimens to go through a reaction.

Effect of Porosity on Dynamic Mechanical Properties and Impact Response Characteristics of High Aluminum Content PTFE/Al Energetic Materials

“…Shen [2] used Taylor bar impact experiments to study the law of deformation and ignition time of PTFE/Ti energetic materials caused by the impact of the material ratio and the impact speed of the bar. Wu et al [3] used drop weight experiments to characterize the reaction characteristics of PTFE/Al and concluded that the characteristic drop height and ignition energy increase with the increase of Al particle size.…”

“…McGregor et al [4] studied the impact response threshold of 40% density PTFE/Al energetic materials under impact. Dolgoborodov et al [5] found that porous PTFE/Al (0.4~0.5 g/cm 3 ) energetic materials can form stable detonation under the impact pressure of 1 GPa. By testing the reaction process of metal fluorocarbon-based reaction materials, Koch et al [6] concluded that the material's ability to react in metal fluorocarbon-based systems is significantly correlated with temperature.…”

A comparative study on the mechanical and reactive behavior of three fluorine-containing thermites

“…Based on this nding, the effects of sintering temperature and composition ratio on the quasi-static reaction of Al/PTFE were ascertained. Wu et al 21 studied the inuence of Al particle size on mechanical properties of Al/PTFE composites, the results show that with the increase of Al particle size, the strength of the composites declined monotonously, and the toughness rose rstly and subsequently decreased. Ding et al 22 utilized a new energy release testing device to investigate the energy release ability of PTFE/Al/CuO.…”

Investigation on the Thermal Behavior, Mechanical Properties and Reaction Characteristics of Al-PTFE Composites Enhanced by Ni Particle

“…It was found that with the increase in Al particle size, the strength and sensitivity of the material decreased and the activation reaction of Al and PTFE became more and more difficult to occur. The formation of circumferential open cracks was a prerequisite for the Al-PTFE specimens to undergo a reactive reaction [ 10 ]. Cai investigated the mechanical properties of Al-W-PTFE materials and found that the addition of W particles could effectively improve the strength of Al-PTFE [ 11 ].…”