Irreversible phase transition and wave propagation in silicate geologic materials
Shock and unloading experiments on quartz and silicate rocks indicate the release adiabats lie below the Hugoniot. The hysteresis and energy dissipation inherent in this situation have important wave propagation implications. On loading, there is pressure-induced transition to the stishovite phase which is not abrupt, with the Hugoniot passing through a metastable mixed phase region for several tens of GPa. One interpretation of the unloading data is that the transition is not reversible, and the material remains in a frozen phase mixture on initial unloading. However, material strength may also play a role. A complete thermodynamically consistent EOS which includes phase transitions and strength effects has been developed and used to examine shock and release data on quartz and silicate rocks in order to quantify the kinetics of the reverse transition and to separate the hysteretic effects due to phase transition kinetics from those due to material strength. The model allows quantitative determination of the effect of transition kinetics on ground shock propagation in silicate materials. 7 refs., 6 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5736772
- Report Number(s):
- SAND-89-0848C; CONF-890812-9; ON: DE89016031
- Resource Relation:
- Conference: American Physical Society topical conference on shock compression of condensed matter, Albuquerque, NM, USA, 14-17 Aug 1989; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Irreversible phase transitions and wave propagation in silicate geologic materials
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