| AVS 60th International Symposium and Exhibition | |
| Synchrotron Analysis Focus Topic | Tuesday Sessions |
| Session SA-TuP |
| Session: | Synchrotron Analysis Poster Session |
| Presenter: | T.M. Willey, Lawrence Livermore National Laboratory |
| Authors: | T.M. Willey, Lawrence Livermore National Laboratory L. Lauderbach, Lawrence Livermore National Laboratory T.W. van Buuren, Lawrence Livermore National Laboratory I.C. Tran, Lawrence Livermore National Laboratory J. Ilavsky, Argonne National Laboratory H.K. Springer, Lawrence Livermore National Laboratory |
| Correspondent: | Click to Email |
HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) is a relatively insensitive high explosive at room temperature. Mesoscale voids are thought to influence sensitivity and detonation properties in polymer bound explosive compositions, where HMX crystals are mixed with, for example, ~5% Viton. HMX molecular crystals undergo a solid-solid phase transition from the so-called beta- to delta- phases at elevated temperatures around 170 Celsius, an prior to this study, little was known about how this phase transition affected mesoscale voids and microstructure. We have measured the ultra-small angle x-ray scattering (USAXS) as the explosive was heated through this phase transition. The USAXS is sensitive to structure from about 10 nm to about 5, and shows how the porosity in these size regimes evolves during the phase change. X-ray computed microtomography was also performed before and after temperature cycling to observe changes on length scales larger than a micron. These results enable studies to determine how the mesocale porosity affects detonation properties in heated HMX-based explosives.
This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.