Unusual plasticity and strength of metals at ultra-short load durations

Kanel, G. I.; Zaretsky, E.; Разоренов, С. В.; Ашитков, С. И.; Фортов, В. Е.

doi:10.3367/ufnr.2016.12.038004

Cited by 9 publications

(2 citation statements)

References 88 publications

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“…In the MD pressure profiles, the melting site is smoothed, but remains noticeable. And if in [43][44][45] the plastic equation of state of matter in the solid phase is used (there are no elastic shock waves) [46][47][48][49][50][51], then MD [2, 5, 7-9, 11, 23, 52, 53] clearly shows the elastic-plastic transition; a detailed experimental and theoretical studies of elastic-plastic transition in ultrashort loading were carried out in the works of Ashitkov, Kanel, Agranat, et al [6,54,55], see also [56,57]. It turns out [11], that there is a superposition of two effects (A) of the ablation imprint of melting on the characteristics and (B) of the formation of an elastic shock wave.…”

Section: Laser Shock Peening By Nanosecond Laser Pulsementioning

confidence: 99%

Picosecond-Nanosecond Laser Flash, Formation of powerful Elastic Waves in Crystals, and Shock Peening

Inogamov¹,

Zhakhovsky²,

Ilnitsky³

et al. 2019

Proceedings of the 32nd International Symposium on Shock Waves (ISSW32 2019)

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Elastic-plastic transformations together or independently from polymorphic phase transitions are important for theory of shock waves. Here we discuss a classification consisting from (I) elastic, (II) split elastic-plastic, and (III) pure plastic shocks. The split shocks means that (1) there are two jumps: the elastic precursor and plastic shock, and that (2) the jumps are independent from each other, the precursor moves with elastic speed of sound overrunning the plastic jump and going further and further ahead as time proceeds and becoming weaker and weaker.We oppose the split shock to the one-wave two zones shock (1W2Z shock). The 1W2Z wave (1) propagates as whole, (2) the plastic shock dynamically supports the elastic one, (3) the distance between the jumps does not change in time; here we say about the distance averaged over time.The powerful elastic shocks (their amplitudes are much higher than are usually suggested for elastic shocks) were found in experiments with femtosecond laser pulses and confirmed in large scale molecular dynamics (MD) simulations. The observation of the 1W2Z shocks is another important finding coming from MD. In the paper below we want to emphasize that the 1W2Z wave (proved to exist in MD) is not some tiny submicron feature belonging to MD or to ultrashort shocks. We hypothesized that it may be detected at spatio-temporal scales significantly larger than micron. Thus it should be included into the above classification as a new regime. It should be placed between the II-nd and III-rd regimes in the old classification.The report is devoted to lasers, shocks, and applications. In the second part of the report the generation and propagation of the shocks created for laser shock peening by lasers with ultrashort or nanosecond pulses are considered.

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Section: Laser Shock Peening By Nanosecond Laser Pulsementioning

confidence: 99%

Picosecond-Nanosecond Laser Flash, Formation of powerful Elastic Waves in Crystals, and Shock Peening

Inogamov¹,

Zhakhovsky²,

Ilnitsky³

et al. 2019

Proceedings of the 32nd International Symposium on Shock Waves (ISSW32 2019)

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“…The pulsed energy release is accompanied by the excitation of compression waves and cavitation phenomena in such melts, what makes it relevant to determine the strength properties of these materials both in the solid and liquid states under pulsed shocks of submicrosecond duration. Experimental studies of the properties of materials under shock loads of microsecond duration are in most cases based on measurements and analysis of the evolution of elastoplastic shock compression waves at various temperatures [9][10][11]. In elastoplastic material an elastic precursor is released in compression wave is distinguished, its amplitude is proportional to the value of the yield strength, and the rate of its decay is proportional to the initial rate of plastic strain.…”

Section: Introductionmentioning

confidence: 99%

The effect of temperature on the Hugoniot elastic limit and the spall strength of a lead-bismuth alloy at the pressure of shock compression up to 2.4 GPa

2023

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Measurements of the Hugoniot elastic limit and the spall strength of the eutectic alloy Bi --- 56.5 mass%, Pb --- 43.5 mass% were carried out at sample temperatures in the range of 20-109oC based on registration and analysis of the evolution of shock compression pulses of various amplitudes. It is shown that an increase in the temperature of the samples leads to a decrease in the Hugoniot elastic limit by 25%, and the spall strength of the alloy under study --- by 30%, regardless of the strain rate. An increase in the strain rate by two orders of magnitude leads to an increase in the spall strength by about three times. Approximation power-law dependences of the decay of the elastic precursor on the thickness of the samples and the spall strength on the strain rate before fracture at normal and elevated temperatures are constructed. Keywords: lead-bismuth eutectic alloy, shock waves, deformation, temperature, Hugoniot elastic limit, spall strength.

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