Study of spallation by sub-picosecond laser driven shocks in metals

Abstract

Abstract. Spallation induced by a laser driven shock has been studied for two decades on time scales of nanosecond order. The evolution of laser technologies now provides access to sources whose pulse duration is under the picosecond, corresponding to characteristic times of numerous microscopic phenomena. In this ultra-short irradiation regime, spallation experiments have been performed with time-resolved measurements of the free surface. In this solicitation type, damage occurs at small scale, leading to micrometric spalls. The VISAR measurements have been complemented with post-test observations and microtomography and compared with numerical simulations to check the models consistency of the laser-matter interaction, shock wave propagation and the dynamic damage criteria ability to reproduce spallation at this ultra-short time scale, inducing strong tensile stress states at very high strain rates.

Resistance to dynamic deformation and fracture of tantalum with different grain and defect structures

“…A detailed discussion of this aspect of the prob lem can be found in [30]. Figure 7 presents the results obtained in this work together with the results obtained from measurements of the spall strength of tantalum by the French authors Cuq Lelandias et al [18] and Roy [31]. It can be seen from this figure that, in the case where the spall is ini tiated by a laser pulse, the spread of the data on the spall strength at the same strain rate can reach 50% and more.…”

“…Salishchev for the assistance in the preparation of ultrafine grained tan talum specimens and performance of their metallo graphic investigations and L.G. Ermolov for the assis MD simulation [18] Laser shock [18] Plate impact [31] This work tance in the preparation and performance of explosive experiments. This study was supported by the Russian Foundation for Basic Research (project no.…”

“…Tantalum has a body centered cubic structure of the crystal lattice, a density of 16.6 g/cm 3 , and a melting point of 3287 K and exhibits a combination of high hardness with high plasticity. The elastoplastic properties and spall frac ture of tantalum under shock wave loading have been investigated in a rather large number of works [9][10][11][12][13][14][15][16][17][18][19][20][21][22], which, however, have remained unclear the mecha nism of the influence of structural factors on these processes. The dynamic elastic limit for tantalum, according to different data, varies in the range from 1.5 to 4.5 GPa, and the spall strength lies in the range from 5 to 10 GPa.…”

Effects of ZrCuAl bulk metallic glasses Poisson’s ratios on spalling process induced by laser shock

“…1 are displayed the terminal spall velocities measured by PDV versus sample thickness. According to shockwave theory, spall velocity decreases with increasing sample thickness in between 150 and 270 µm due to hydrodynamic damping [13], [14]. It appears for a fixed thickness that spall velocities are the highest for the Cu-richest composition (Zr 45 Cu 45 Al 10 ) and the lowest for the Zr-richest specimens (Zr 60 Cu 30 Al 10 ).…”

Влияние высокотемпературного отжига на сопротивление высокоскоростному деформированию и разрушению тантала при температуре 20 и 500-=SUP=-o-=/SUP=-C

“…5), в сравнении с известными литературными данными. Под скоростью деформирования здесь понимается скорость расширения вещества в волне разрежения, определяемая как [19] Plate impact [4] Single crystals [4] This work Plate impact [20] Quasi static loading -(0.…”