Ratchet growth in recycled PBX 9502
- Los Alamos National Laboratory
PBX 9502 is a plastic-bonded high explosive (PBX) containing 95 weight% TATB (triaminotrinitrobenzene) crystals in a polymer binder. TATB crystals are graphitic in nature, with a sheet-like structure and anisotropic CTE. Although the mechanism is not understood, solid-pressed TATB composites have been observed to undergo irreversible volume change ('ratchet growth') upon thermal cycling . This phenomenon has been studied but many aspects remain elusive and uncharacterized. Engineering or performance changes associated with ratchet growth have often been attributed to changes in density alone. We propose that the density changes which accompany ratchet growth involve a unique form of micro-damage distinguishable from the pore structure associated with low-pressed density. We have performed ratchet growth studies on Recycled PBX 9502 between -54 to 80{sup o}C with density changes of about 1.5%. Specimens of the same density were obtained using a lower pressure in the manufacturing process. Comparative measurements were made using quasi-static uniaxial tension tests, as well as micro x-ray computed tomography and ultra-small angle neutron scattering experiments. Through these measurements we have shown that ratchet grown PBX 9502 has properties quite different from predictions based on density alone. The pore size distribution of ratchet grown specimens is unique and easily distinguished from parts pressed to an equivalent density.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 956582
- Report Number(s):
- LA-UR-09-01448; LA-UR-09-1448; TRN: US201014%%1951
- Resource Relation:
- Conference: Society for Experimental Mechanics, Annual Conference ; June 1, 2009 ; Albuquerque, NM
- Country of Publication:
- United States
- Language:
- English
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