Effect of addition of HTa to Al/PTFE under quasi-static compression on the properties of the developed energetic composite material

Abstract

To study the mechanical properties and reaction characteristics of Al/HTa/PTFE reactive materials under quasi-static compression, five types of Al/HTa/PTFE specimens with different HTa contents were prepared for quasi-static compression tests. The fracture of selected specimens was characterized by scanning electron microscopy (SEM). The quasi-static compression reaction residue underwent X-ray diffraction (XRD) phase analysis, and the chemical reaction mechanism was analyzed based on the result. As revealed from the results, the introduction of HTa significantly influenced the strength of the composites. With the increase in HTa content, the compressive strength of Al/HTa/PTFE materials first decreased and then increased. Under a HTa content of 30%, the compressive strength increased by nearly 10.6%. The microstructure shows that the HTa content in the Al/HTa/PTFE materials affects the bonding force between the metal particles and the PTFE matrix, the integrity of the PTFE matrix and the formation of PTFE bridging filaments between the deformed surfaces of the PTFE matrix, resulting in a difference in compressive strength. HTa increased the reaction duration and smoke concentration, and induced a similar white burning flame at the later phase of the reaction, with greater flame luminosity. The high temperature of the crack tip of the specimen induced the reaction of Al and PTFE and released considerable heat causing HTa to release H₂, synthesized TaC, and increased the energy density, which achieved the purpose of enhancing the mechanical properties and reaction characteristics of the material.