Measurements of laser driven spallation in tin and zinc using an optical recording velocity interferometer system

Moshe, E.; Eliezer, S.; Dekel, E.; Henis, Z.; Ludmirsky, A.; Goldberg, Ira B.; Eliezer, Dan

doi:10.1063/1.371352

Cited by 31 publications

(15 citation statements)

References 10 publications

(10 reference statements)

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“…Within the acoustic approximation, a simple relationship can be used : σ R = 1/2ρ 0 C 0 u where ρ 0 is the mass density and C 0 is the bulk sound speed (Antoun et al 2002). For laser shocks below 45 GPa, corresponding to shock breakout of about 10 GPa at the free surface, σ R is about 1.5-1.7 GPa, that is about twice the values determined for solid tin under explosive loading (Grady 1988) or plate impacts (Kanel et al 1996), but close to the 1.4 GPa value measured under laser shocks of lower intensity (Moshe et al 1999). This confirms the known increase of the spall strength with increasing strain rate and decreasing load duration (Antoun et al 2002;Moshe et al 1999).…”

Section: Resultssupporting

confidence: 51%

“…For laser shocks below 45 GPa, corresponding to shock breakout of about 10 GPa at the free surface, σ R is about 1.5-1.7 GPa, that is about twice the values determined for solid tin under explosive loading (Grady 1988) or plate impacts (Kanel et al 1996), but close to the 1.4 GPa value measured under laser shocks of lower intensity (Moshe et al 1999). This confirms the known increase of the spall strength with increasing strain rate and decreasing load duration (Antoun et al 2002;Moshe et al 1999). For increasing shock pressures, when clear signs of (partial) melting can be inferred from microscopic observations of the recovered samples, faster oscillations appear and the velocity pullback is shown to decrease (see double arrows in Fig.…”

Section: Resultssupporting

confidence: 51%

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Dynamic fragmentation of laser shock-melted tin: experiment and modelling

et al. 2009

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Dynamic fragmentation of shock-loaded metals is an issue of considerable importance for both basic science and a variety of technological applications, such as pyrotechnics or inertial confinement fusion, the latter involving high energy laser irradiation of thin metallic shells. Whereas spall fracture in solid materials has been extensively studied for many years, little data can be found yet about the evolution of this phenomenon after partial or full melting on compression or on release. Here, we present an investigation of dynamic fragmentation in laser shock-melted tin, from the "micro-spall" process (ejection of a cloud of fine droplets) occurring upon reflection of the compressive pulse from the target free surface, to the late rupture observed in the unspalled melted layer (leading to the formation of larger spherical fragments). Experimental results consist of time-resolved velocity measurements and post-shock observations of recovered targets and fragments. They provide original information regard-T. de. Rességuier (ing the loss of tensile strength associated with melting, the cavitation mechanism likely to occur in the melted metal, the sizes of the subsequent fragments and their ejection velocities. A theoretical description based on an energetic approach adapted to the case of a liquid metal is implemented as a failure criterion in a onedimensional hydrocode including a multi-phase equation of state for tin. The resulting predictions of the micro-spall process are compared with experimental data. In particular, the use of a new experimental technique to quantify the fragment size distributions leads to a much better agreement with theory than previously reported. Finally, a complementary approach focused on cavitation is proposed to evaluate the role of this phenomenon in the fragmentation of the melted metal.

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Section: Resultssupporting

confidence: 51%

Section: Resultssupporting

confidence: 51%

Dynamic fragmentation of laser shock-melted tin: experiment and modelling

et al. 2009

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“…17,18,22,36 This confirms the well-known increase in dynamic tensile strength with increasing strain rate and decreasing load duration. 35,[37][38][39] The computed thickness of the spalled layer is 16 m in the thinnest sample, 90 m in the 250-m-thick target, and 100 m in the other two. The rise time of the spall pulse, which is related to the gradual evolution of damage, is too steep in the computed profiles because rupture is assumed to be instantaneous in the model.…”

Section: Free Surface Velocitymentioning

confidence: 99%

Effects of theα−εphase transition on wave propagation and spallation in laser shock-loaded iron

Rességuier

Hallouin

2008

Phys. Rev. B

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Despite extensive research work on the ␣-phase transition occurring in shock-loaded iron, the kinetics of this transformation remain largely unknown. Here, we present time-resolved free surface velocity measurements in iron foils of thicknesses ranging from 150 to 520 m subjected to laser shocks of peak pressure of about 130 GPa and duration of about 3 ns. The records show an elastic precursor followed by a plastic front, but the double wave structure that is usually associated with the phase change does not appear over such short propagation distances. The measured profiles are compared to the predictions of one-dimensional simulations involving rate-dependent descriptions of both twinning and phase transitions. Such comparisons provide an estimate of a time constant governing the transformation kinetics, which is found to strongly condition the evolution and attenuation of the pressure pulse during its propagation. The spall stress evaluated from the records is shown to be significantly higher after the ␣--␣ cycle. Metallurgical observations of the recovered samples confirm both the phase transition and the spall damage inferred from the velocity profiles. Finally, they show the very clear change in fracture surface morphology to the so-called smooth spall expected above the phase transformation.

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“…The choice of strain rates is based on those generated during shock loading using picosecond and femtosecond laser pulses. [17,28,29] Based on Eqs. [3] and [4], for the conditions of uniaxial stress loading, the effective von Mises stress (r e ) reduces to the stress in the loading direction (r x ), and the effective strain (e e ) reduces to the strain in the loading direction (e x ).…”

Section: Tension-compression Strength Asymmetry In Nanocrystallimentioning

confidence: 99%

“…[17] Shock loading using short (nanosecond) laser pulses leads to peak strain rates exceeding 10 7 s À1 , [25][26][27] whereas the use of ultrashort (femtosecond) laser pulses results in strain rates exceeding 10 8 s À1 . [28,29] As a result, MD simulations are carried out to understand the macroscopic deformation behavior of nanocrystalline Cu with an average grain size of 6 nm at ultrahigh strain rates ( ‡10 8 s À1 ). Three aspects of deformation behavior are studied: the tension-compression strength asymmetry, the biaxial yield surface, and the three-dimensional (3-D) yield surface.…”

Section: Introductionmentioning

confidence: 99%

Atomic-Scale Study of Plastic-Yield Criterion in Nanocrystalline Cu at High Strain Rates

Dongare

Rajendran

LaMattina

et al. 2009

Metall Mater Trans A

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Large-scale molecular dynamics (MD) simulations are used to understand the macroscopic yield behavior of nanocrystalline Cu with an average grain size of 6 nm at high strain rates. The MD simulations at strain rates varying from 10 9 s À1 to 8 9 10 9 s À1 suggest an asymmetry in the flow stress values in tension and compression, with the nanocrystalline metal being stronger in compression than in tension. The tension-compression strength asymmetry is very small at 10 9 s À1 , but increases with increasing strain rate. The calculated yield stresses and flow stresses under combined biaxial loading conditions (X-Y) gives a locus of points that can be described with a traditional ellipse. An asymmetry parameter is introduced that allows for the incorporation of the small tension-compression asymmetry. The biaxial yield surface (X-Y) is calculated for different values of stress in the Z direction, the superposition of which gives a full threedimensional (3-D) yield surface. The 3-D yield surface shows a cylinder that is symmetric around the hydrostatic axis. These results suggest that a von Mises-type yield criterion can be used to understand the macroscopic deformation behavior of nanocrystalline Cu with a grain size in the inverse Hall-Petch regime at high strain rates.

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Measurements of laser driven spallation in tin and zinc using an optical recording velocity interferometer system

Cited by 31 publications

References 10 publications

Dynamic fragmentation of laser shock-melted tin: experiment and modelling

Dynamic fragmentation of laser shock-melted tin: experiment and modelling

Effects of theα−εphase transition on wave propagation and spallation in laser shock-loaded iron

Atomic-Scale Study of Plastic-Yield Criterion in Nanocrystalline Cu at High Strain Rates

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