Rex P. Hjelm, a scientist at the New Mexico Consortium and Los Alamos National Laboratory, and Joseph T. Mang of Los Alamos National Laboratory have published a new paper titled: “Preferred Void Orientation in Uniaxially Pressed PBX 9502”. This work has recently been accepted to the journal Propellants, Explosives, Pyrotechnics.
This research used the scattering of neutrons to study small voids or spaces in the material. The material, PBX 9502, which is used in defense programs weapons systems, and has seen considerable work to understand the materials properties and performance, consists of crystals of the insensitive high explosive, TATB (1,3,5-triamino-2,4,6-trinitrobenzene), bound by an inert, polymeric, Kel-F 800. This work addresses issues important to understanding the material’s safety and surety.
PBX 9502 is molded into useful shapes by compression under high pressure and temperature. This process results in the inclusion of extremely small (1 nm to approximately 2 µm, or 0.00000004 to 0.0001 inch), asymmetric voids as disks, flattened along the line of the applied pressure. This study for the first time detailed the average shape and dimensions of the voids and their spatial interactions along lines of sight corresponding to applied pressure and at right angles to the line of pressure.
The characteristics of the voids studied in this work are important for understanding the performance of the material. The researchers used neutrons, which are uniquely suited for this study, to provide data for to improve predictive capabilities on the safety and performance of these materials.
To read the Hjelm and Mang’s entire paper see: Preferred Void Orientation in Uniaxially Pressed PBX 9502