Influence of Explosive Pressing Technique Parameter on Microstructure and Mechanical Properties of polymer-bonded energetic materials

Powder compaction process is the most widely used technology to fabricate polymer bonded explosives (PBX). The processing parameters have important effects on the microstructures and mechanical properties of the final products, and this work systematically studies these effects. Cylindrical PBX samples are fabricated with different preparation parameters, including pressing rates, porosity factors, temperatures and granular compositions, and examined with scanning electron microscopy (SEM) and computer tomography to characterize their initial microstructures. The samples are then tested with uniaxial compression experiments under strain rates varying from 0.0003 s-1to 7000 s-1to obtain the stress—strain responses. A modified Zhu-Wang-Tang constitutive model is then applied to describe mechanical response of the PBX samples, with the effects of strain rate beging considered. Postmortem samples subjected to quasi-static compression are examined via SEM and the deformation and damage mechanisms are analyzed (inner/inter-granular fractures and interfacial debonding). This work systematically reveals the relations between preparation methods, material micro-structures and compressive properties. It provides data of micro-structural characteristics and mechanical properties and proposes an efficient non-linear constitutive model for the PBX. The investigation is valuable for fabrication optimization and mechanical performance assessment of PBX.