The Evolution of Void Morphology in Pressed TATB with Density and Particle Size

Microstructure plays a significant role in determining the shock sensitivity and performance of pressed high explosives (HEs). This is particularly true for the insensitive high explosive TATB whose corner turning ability is affected by subtle changes in its initial particle size distribution (PSD). This is surprising, as the TATB particles are considerably altered during consolidation. It is likely that the importance of the initial TATB PSD resides in its influence on the final void size size distribution, whose viscous collapse under shock conditions can lead to the formation of hot spots that are known to influence initiation. There is an increasing need for detailed microstructural information such as void size and morphology within pressed parts to support HE production and modeling capabilities. Little is known of the relationship between the initial HE PSD and void size and morphology within a compact. Small-angle scattering techniques were used to study the evolution of this relationship in TATB samples pressed from three distinct PSDs over the density range from 1.55 – 1.89 g/cc. In all samples studied, the void volume is well described as ramified networks of voids. The network size and connectivity will be discussed in terms of the initial TATB PSD and density.