Mass Ejection from the Free Surface of Shock-Loaded Metallic Samples

Chéret, Roger; Chapron, P.; Elias, P.; Martineau, J.

doi:10.1007/978-1-4613-2207-8_94

Cited by 17 publications

(12 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1b), usually referred to as "micro-jetting" (Asay et al 1976;Andriot et al 1982;Cheret et al 1986;Zellner et al 2007). Considering the smooth surfaces of the tin samples used in our experiments (roughness ∼ µm), this process is expected to be limited to extremely small masses ).…”

Section: Phenomenological Analysismentioning

confidence: 97%

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

et al. 2009

View full text Add to dashboard Cite

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.

show abstract

Section: Phenomenological Analysismentioning

confidence: 97%

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

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Indeed, when the release waves issued from the reflection of the shockwave onto the free surface reach the backside of our crystal, the system comes off the piston that was applied to support the shock. Then the crystal becomes isolated, and when the sheets are ejected, it loses a very small part of its velocity (momentum conservation) that can no more be compensated by the piston, unlike what occurs in hydro computations [1,[17][18] and experiments [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] where the samples have "infinite" (very large) dimensions. Other sources may also explain this difference; in particular the conditions of simulation (supported shockwave at extreme pressure).…”

Section: The Continuum Point Of Viewmentioning

confidence: 99%

“…the distributions of the ejecta in size and velocity. Past theoretical and experimental efforts have shown that surface imperfections of machined material (in particular two-dimensional periodic features for metals) are the main cause of ejecta production [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Mass-velocity and size-velocity distributions of ejecta cloud from shock-loaded tin surface using atomistic simulations

Durand

Soulard

2015

Journal of Applied Physics

View full text Add to dashboard Cite

Abstract:The mass (volume and areal densities) versus velocity as well as the size versus velocity distributions of a shock-induced cloud of particles are investigated using large scale molecular dynamics (MD) simulations. A generic three-dimensional tin crystal with a sinusoidal free surface roughness (single wavelength) is set in contact with vacuum and shock-loaded so that it melts directly on shock. At the reflection of the shock wave onto the perturbations of the free surface, two-dimensional sheets/jets of liquid metal are ejected. The simulations show that the distributions may be described by an analytical model based on the propagation of a fragmentation zone, from the tip of the sheets to the free surface, within which the kinetic energy of the atoms decreases as this zone comes closer to the free surface on late times. As this kinetic energy drives (i) the (self-similar) expansion of the zone once it has broken away from the sheet and (ii) the average size of the particles which result from fragmentation in the zone, the ejected mass and the average size of the particles progressively increase in the cloud as fragmentation occurs closer to the free surface.Though relative to nanometric scales, our model may help in the analysis of experimental profiles.2

show abstract

“…It has long been known that a shock-driven material can emit a fine spray of particles (ejecta) from its free surface, [1][2][3][4][5][6][7][8] which can corrupt optical and electrical measurements at metal surfaces. The process can also afflict applications like inertial confinement fusion (ICF) by mixing cold ablator material into the hot thermonuclear fuel.…”

Section: Introductionmentioning

confidence: 99%

Ejecta source model based on the nonlinear Richtmyer-Meshkov instability

Dimonte

Terrones

Cherne

et al. 2013

Journal of Applied Physics

117

View full text Add to dashboard Cite

Articles you may be interested inReshocked Richtmyer-Meshkov instability: Numerical study and modeling of random multi-mode experiments Phys. Fluids 26, 084107 (2014); 10.1063/1.4893678 Simulations and model of the nonlinear Richtmyer-Meshkov instability Phys. Fluids 22, 014104 (2010); 10.1063/1.3276269 Richtmyer-Meshkov instability induced by shock-bubble interaction: Numerical and analytical studies with experimental validationWe describe a simple algebraic model for the particulate spray that is ejected from a shocked metal surface based on the nonlinear evolution of the Richtmyer-Meshkov instability (RMI). The RMI is a shock-driven hydrodynamic instability at a material interface in which the dense and tenuous fluids penetrate each other as spikes and bubbles, respectively. In our model, the ejecta areal density is determined by the product of the post-shock metal density and the saturated bubble amplitude, which depends on both the amplitude and wavelength of the initial surface imperfections of the metal. The maximum ejecta velocity is determined by the ever-growing spikes, which are accelerated relative to the RMI growth rate by the spatial harmonics that sharpen them. The model is formulated to fit new hydrodynamics and molecular dynamics simulations of the RMI and validated by existing ejecta experiments over a wide range of material properties, shock strengths, and surface perturbations. The results are also contrasted with existing ejecta source models. V C 2013 American Institute of Physics. [http://dx.

show abstract

Mass Ejection from the Free Surface of Shock-Loaded Metallic Samples

Cited by 17 publications

References 1 publication

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

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

Mass-velocity and size-velocity distributions of ejecta cloud from shock-loaded tin surface using atomistic simulations

Ejecta source model based on the nonlinear Richtmyer-Meshkov instability

Contact Info

Product

Resources

About