Relating Performance Variation Among Different Lots of a Plastic Bonded High Explosive to Microstructural Differences

The performance of plastic bonded high explosives (e. g. as measured by their corner turning ability) is known to vary among material lots. It has been speculated that subtle differences in the microstructure among lots are at the root of these variations. While such formulation-related microstructural variations can be expected in the large-scale production of plastic bonded explosives (PBXs), to influence performance, the variations must persist and translate to microstructural differences in the high density pressing that are used during performance testing. To better understand the relationship between performance and as-pressed microstructure, a systematic study of the microstructure of high-density pressings of different lots of PBXs is necessary.

Small-angle x-ray scattering (SAXS) methods were utilized to characterize the microstructure of high-density pressings of several different lots of plastic bonded high explosives. SAXS provides a means to extract new and potentially valuable microstructural information that can help unravel the performance vs. microstructure puzzle of PBXs. By modeling the microstructure of the consolidated high explosives as a ramified network of pores, subtle differences in microstructural features among material lots, including void size and void and surface dimensionality, can be quantified. These parameters will be correlated with known performance data to evaluate their influence on the known performance variation among the different PBX lots.