About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Dynamic Behavior of Materials IX
|
Presentation Title |
Simultaneous Lattice Strain and Bulk Strain Measurements during Thermal Cycling of PBX 9502 |
Author(s) |
Matthew Schmitt, Bjorn Clausen, Travis Carver, Sven C. Vogel, John D. Yeager |
On-Site Speaker (Planned) |
Matthew Schmitt |
Abstract Scope |
Triaminotrinitrobenzene (TATB) exhibits irreversible volume expansion upon thermal cycling (“ratchet growth”). Various mechanisms have historically been proposed to explain this phenomenon. Since TATB powder does not ratchet grow, but consolidated pellets do, one hypothesis is that residual lattice strain from the compaction process is released when TATB is thermally cycled, causing volume expansion. To test this, we here simultaneously measure lattice strain and bulk strain during thermal cycling at the Los Alamos Neutron Science Center. Lattice strain was measured using neutron diffraction while the samples were cycled several times from ~25-160°C. Changes in lattices parameters due to temperature were completely reversible and so cannot drive the observed ratchet growth. Recent experiments and analysis have suggested microcracking at grain boundaries and interfaces is instead responsible, itself driven by the high anisotropy in the material. Implications of these findings for mechanical and ignition modeling will be discussed. |
Proceedings Inclusion? |
Planned: |
Keywords |
Composites, Characterization, Mechanical Properties |