Dynamics of deformation band formation investigated by high-speed techniques during creep in an AlMg alloy

Shibkov, A. A.; Zheltov, M. A.; Gasanov, M. F.; Zolotov, A. E.; Denisov, A. A.; Lebyodkin, M.A.

doi:10.1016/j.msea.2019.138777

Cited by 18 publications

(25 citation statements)

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“…Embryo bands of different type are characterized by different dynamics. The dynamics and geometry of the first two types are identical, as described in detail in [12,29,30]. Up to about half the cross section of a flat sample, the embryo band tip grows at an approximately constant velocity at an angle of 58-63° to the tensile axis.…”

Section: A Types Of Embryo Deformation Bandsmentioning

confidence: 96%

“…Details of the experiment and methodological aspects were described elsewhere [12,30] and will be briefly outlined here. Tensile specimens with a dog-bone shape and a gauge size of 6×3×0.2 mm 3 were cut along the rolling direction from a cold-rolled sheet of a polycrystalline aluminummagnesium AlMg6 (AA5059) alloy with the chemical composition Al-6.15%Mg-0.65%Mn-0.25%Si-0.21%Fe (wt.%).…”

Section: Experimental Procedures and Data Processingmentioning

confidence: 99%

“…The voltage from the sensor was amplified by 40 dB with the aid of a AEP5 preamplifier (Vallen-Systeme) and recorded continuously without a threshold at a 5 MHz sampling rate and 16-bit amplitude resolution. The low-frequency part of the AE spectrum, studied earlier in [29,30], was suppressed by high-pass filters set at 25 kHz, 50 kHz, or 100 kHz depending on the research tasks.…”

Section: Experimental Procedures and Data Processingmentioning

confidence: 99%

“…Nucleation and growth of an embryo band was also found for creep. Moreover, video-recording with a speed of 25 000 fps allowed to characterize an elliptic shape of the embryo band contour, jumps in the velocity of its tip, and the instant of its arrival to the opposite side of a flat sample, i.e., the end of formation of a complete deformation band [29,30].…”

Section: Introductionmentioning

confidence: 99%

“…In the previous works by the authors [29,30], the dynamics of deformation bands was studied under conditions of discontinuous creep of an AlMg6 alloy with the aid of the AE method in the low-frequency range of ~ 10 Hz -10 kHz and synchronous video-recording of the specimen surface with a time resolution of 40-50 μs. It allowed to establish that the main AE occurs when the growing embryo band reaches the opposite side of the specimen and to correlate the jump in the stress drop rate with the first AE peak with a rise time of ~ 1 ms.…”

Section: Introductionmentioning

confidence: 99%

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Millisecond dynamics of deformation bands during discontinuous creep in an AlMg polycrystal

et al. 2020

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Formation of bands of macroscopic strain localization during staircase creep in an AlMg polycrystal is studied by the acoustic emission (AE) technique and high-speed video-recording with an image acquisition rate up to 50 000 frames per second. The simultaneous measurements by two methods allow to distinguish different types of embryo deformation bands and concomitant AE signals and establish correlations between the band evolution and the acoustic response. It is found that the fastest stages of band formation, associated with its emergence to the surface and subsequent accelerated expansion, generate complex AE bursts in the frequency band ~0.05-1 MHz. The correlations hidden in the complex structure of an individual acoustic burst are investigated by methods of statistical and fractal analysis. On the other hand, relationships between average parameters of various physical responses to discontinuous creep are assessed. Particularly, a close correspondence is found between the envelope of the acoustic burst and the rate of stress change during formation of a single deformation band. Evolution of dynamical behavior of embryo bands with increasing creep stress is discussed. Notably, a qualitative change in the AE waveform observed on approaching the ultimate stress is considered from the viewpoint of anticipation of the oncoming fracture.

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Section: A Types Of Embryo Deformation Bandsmentioning

confidence: 96%

Section: Experimental Procedures and Data Processingmentioning

confidence: 99%

Section: Experimental Procedures and Data Processingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations