Abstract / Description of output
A two-wave shock structure-elastic precursor followed by an inelastic compression wave-is observed in single crystal and polycrystalline diamond laser shock compressed to peak stresses as high as 800 GPa. The Hugoniot elastic limits are measured to be 80 (+/-12), 81 (+/-6), and 60 (+/-3) GPa for the <100 >, <110 >, and <111 > orientations of single crystals with the directional dependence attributable to the relative increase in strength under confining stress. These values imply a single crystal yield strength approximately 1/3 of theoretical predictions. The measurements reveal clear deviations from an elastic-plastic response upon dynamic yielding with significant relaxation toward an isotropic stress state for shock stresses of at least 160 GPa. Previously reported signatures of melting at 700-800 GPa along the diamond Hugoniot may be related to the transition from a two-wave to a single-wave structure, supporting the interpretation that melting begins at lower stresses (similar to 600 GPa) with the appearance of an optically reflecting phase of carbon.
Original language | English |
---|---|
Article number | 014111 |
Number of pages | 19 |
Journal | Physical review B |
Volume | 81 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2010 |
Keywords / Materials (for Non-textual outputs)
- SINGLE-CRYSTAL
- THEORETICAL STRENGTH
- DYNAMIC COMPRESSION
- WAVE COMPRESSION
- PHASE-TRANSITION
- HIGH-PRESSURES
- SILICON
- LASER
- ALUMINUM
- INTERFEROMETER