Initial configuration of single crystal aluminium with a nanogroove, viewed along the x-axis ().
Microscopic morphology evolution of microjet formation for the case of shock stress 42.3 GPa, which is below the release melting stress. Both sides of the groove are in solid state (b)-(e), and only a slender microjet morphology forms (e).
Microscopic morphology evolution of microjet formation for the case of shock stress 73.2 GPa. Release melting appears, and a solid-molten mixing region near the surface forms (e).
Microscopic morphology evolution of microjet formation for the case of shock stress 91.8 GPa. The moving of release melting interface is rapid (c)-(d), and at 20 ps, the whole region near surface has already melted (e). In this case, the effect of material strength is no more evident.
Variation of (a) the microjetting factor R and (b) the head velocity of the microjet vh with the post-shock particle velocity.
The relative mass distribution of microjet in distance (a) and in velocity (b) for different post-shock particle velocities (piston velocities).
The source of microjet matter (red regions) for different piston velocities. Lower and upper are before and after shock loading (40 ps) states, respectively. For piston velocity 2.0 km/s, the microjet matter comes from the bottom of the groove; for piston velocity above 3.0 km/s, the sources of microjets are already throughout the whole groove, due to release melting.
Average velocity evolution of microjet for piston velocities 2.0 km/s and 3.5 km/s. Both cases undergo a rapid acceleration stage before 6 ps, which corresponds to the rapid increase and release of stress as shown in Fig. 10 .
Evolution of average stress-volume tensor and temperature of microjet with time. S1 and S2 represent the microjet matter for 2.0 km/s (before melting) and 3.5 km/s (after melting), respectively. The average temperature of microjet S1 (piston velocity 2.0 km/s) will reduce to below the melting point, suggesting the probability of microjet matter solidification.
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