Elastic-plastic deformation of molybdenum single crystals shocked along [100]
- Washington State Univ., Pullman, WA (United States)
To understand the elastic-plastic deformation response of shock-compressed molybdenum (Mo) – a body-centered cubic (BCC) metal, single crystal samples were shocked along the [100] crystallographic orientation to an elastic impact stress of 12.5 GPa. Elastic-plastic wave profiles, measured at different propagation distances ranging between ~0.23 to 2.31 mm using laser interferometry, showed a time-dependent material response. Within experimental scatter, the measured elastic wave amplitudes were nearly constant over the propagation distances examined. These data point to a large and rapid elastic wave attenuation near the impact surface, before reaching a threshold value (elastic limit) of ~3.6 GPa. Numerical simulations of the measured wave profiles, performed using a dislocation-based continuum model, suggested that {110}<111> and/or {112}<111> slip systems are operative under shock loading. In contrast to shocked metal single crystals with close-packed structures, the measured wave profiles in Mo single crystals could not be explained in terms of dislocation multiplication alone. A dislocation generation mechanism, operative for shear stresses larger than that at the elastic limit, was required to model the rapid elastic wave attenuation and to provide a good overall match to the measured wave profiles. However, the physical basis for this mechanism was not established for the high-purity single crystal samples used in this study. As a result, the numerical simulations also suggested that Mo single crystals do not work harden significantly under shock loading in contrast to the behavior observed under quasi-static loading.
- Research Organization:
- Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP)
- Grant/Contract Number:
- NA0002007
- OSTI ID:
- 1342518
- Journal Information:
- Journal of Applied Physics, Vol. 121, Issue 4; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Elastic-plastic deformation of molybdenum single crystals shocked to 12.5 GPa: Crystal anisotropy effects
|
journal | February 2019 |
Shock compression/release of magnesium single crystals along a low-symmetry orientation: Role of basal slip
|
journal | September 2019 |
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