Dynamic dragging of dislocations

Al'shitz, V A; Indenbom, V. L.

doi:10.1070/pu1975v018n01abeh004689

Cited by 129 publications

(54 citation statements)

References 3 publications

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“…For sufficiently high strain rates, the dominant drag mechanism becomes the phonon viscosity. Because the phonon viscosity is proportional to the temperature, for very high strain rates one can expect an increase in the flow stress with an increase in temperature [3] as it is shown in Fig. 1.…”

Section: Introductionmentioning

confidence: 84%

Rate and temperature effects on the flow stress and tensile strength of metals

Kanel

2012

AIP Conference Proceedings

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Some new and obtained earlier experimental data on the elastic precursor decay and rise times of plastic shock waves in several metals and alloys at normal and elevated temperatures are discussed. The time range available for measurements has been expanded to picoseconds that allows approaching ultimate shear and tensile strengths and observations of general trends. Results of measurements have been transformed into dependences of plastic strain rate on the shear stress.

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Section: Introductionmentioning

confidence: 84%

Rate and temperature effects on the flow stress and tensile strength of metals

Kanel

2012

AIP Conference Proceedings

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“…Alshits and V.L. Indenbom, 15 and is compared with directly measured values by K.M. Jassby and T. Vreeland 16 in Figure 1.…”

Section: Fluid Dynamicsmentioning

confidence: 97%

Dislocation motion in phonon liquids

Gilman

2009

JOM

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“…For many crystal bodies, this dependence is sharply enhanced when the strain rate exceeds 10 3 -10 4 s -1 ; this behavior is interpreted as a consequence of change in the mechanism of motion of dislocations from thermal fluctuation to overbarrier controlled by the phonon friction [12]. The phonon friction increases almost linearly with the velocity of dislocations.…”

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confidence: 89%

Mechanical and optical properties of vanadium under shock picosecond loads

et al. 2015

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The development of the experimental technique for the generation and diagnostics of shock wave phe nomena in solids and methods of atomistic simulation of processes of deformation and fracture stimulates interest in studies of temperature-rate dependences of the resistance to deformation and fracture of metals in a wide range of strain rates. Significant progress in studies of strength and elastic-plastic properties of materials at extremely short durations of loads is achieved with the use of pico and femtosecond laser pulses [1][2][3][4][5][6][7][8]. In particular, the ultimately possible ("ideal") bulk and shear strengths of aluminum [1,5] and iron [6,8] were closely approached in the picosec ond time range. The compression stresses detected behind elastic shock waves reached 20.5 GPa for alu minum and 27.5 GPa for iron, which are higher than the dynamic yield stress of sapphire and are compara ble with the elastic limit of diamond. For the develop ment of technologies of processing of materials with the use of femtosecond laser techniques, it is undoubt edly useful to know possible transient high yield stresses in this time range. Experiments with ultrashort shock pulses are closest in the space-time parameters to the conditions implemented in molecular dynamics calculations [9][10][11]. These experiments are used to test new interatomic interaction potentials and stimu late the formulation of new problems for atomistic simulation.It is known that the yield stress of solids increases with the loading rate. For many crystal bodies, this dependence is sharply enhanced when the strain rate exceeds 10 3 -10 4 s -1 ; this behavior is interpreted as a consequence of change in the mechanism of motion of dislocations from thermal fluctuation to overbarrier controlled by the phonon friction [12]. The phonon friction increases almost linearly with the velocity of dislocations. The yield stress should correspondingly increase with the strain rate.Tension induced fast fracture of condensed matter occurs through the nucleation, growth, and coales cence of numerous cavities. Since the rate of all these processes is limited, the resistance to fracture increases with a decrease in the action time.It is important that reasonable agreement can be reached between the results of shock wave experi ments with micron and submicron thick samples and the data obtained for millimeter samples, the decay of an elastic shock compression wave can be described by a single dependence, and the relation between the shear stress and the initial plastic strain rate can finally be obtained in a record wide range of this rate from 10 3 to 10 9 s -1 [13]. The experimental data for alumi num are well approximated by a simple power law [13], and the decay curve of an elastic shock wave in iron is clearly separated into two segments [8], which apparently correspond to the weak and strong branches of the general dependence of the yield stress on the strain rate discussed above. It is necessary to accumulate such experimental data in order to deter min...

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Dynamic dragging of dislocations

Cited by 129 publications

References 3 publications

Rate and temperature effects on the flow stress and tensile strength of metals

Rate and temperature effects on the flow stress and tensile strength of metals

Dislocation motion in phonon liquids

Mechanical and optical properties of vanadium under shock picosecond loads

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