Deformation mechanism study of a hot rolled Zr-2.5Nb alloy by transmission electron microscopy. I. Dislocation microstructures in as-received state and at different plastic strains

Long, Fei; Daymond, Mark R.; Yao, Zhongwen

doi:10.1063/1.4913605

Cited by 14 publications

(8 citation statements)

References 25 publications

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“…A film showing this sequence is provided as Supplementary Data (Video 1). This dislocation pinning phenomenon is consistent with previous post-irradiation straining experiments [32,18,33,34]. The dislocations observed in this sequence present a V-shape and the motion of the tip of the V-shape is along the [110] axis.…”

Section: First Irradiation Stepsupporting

confidence: 90%

In-situ TEM irradiation creep experiment revealing radiation induced dislocation glide in pure copper

et al. 2021

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In-situ straining experiments were performed on pure copper to investigate dislocation motion under heavy ion irradiation at high stress levels. The unpinning of dislocations from irradiation defects followed by glide was observed under irradiation at stress level just below the critical stress for dislocation glide without irradiation. This phenomenon was unraveled for the first time in copper. The dislocation dynamics recorded in-situ was statistically analyzed using digital image processing to determine the pinning lifetime. Quantitative analysis of pinning lifetimes have been performed, suggesting that a cascade related mechanism is operative to explain the fast dislocation glide under irradiation. This work provides a new insight on the irradiation creep deformation at high stress level.

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Section: First Irradiation Stepsupporting

confidence: 90%

In-situ TEM irradiation creep experiment revealing radiation induced dislocation glide in pure copper

et al. 2021

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“…Basal and pyramidal glide of 1/3 1210 screw dislocations are therefore two facets of the same deformation mode, with basal and pyramidal glide being favoured respectively at low and high stress. Experimental conditions usually correspond to the low stress regime, thus explaining why basal glide is the secondary slip system usually reported for 1/3 1210 dislocations [3,[5][6][7][8][9][10]. In particular, this preference for basal slip at low stress is fully compatible with the TEM observations of Caillard et al [7] during in situ tensile experiments showing that basal glide is an elementary slip system and not a combination of two different slip systems.…”

Section: Basal and Pyramidal Slipsupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

“…Numerous transmission electron microscopy observations [3][4][5][6][7] have provided evidences of basal slip at various temperatures. Post-mortem TEM [3,6] show the presence of a dislocations lying in the basal planes at room temperature after sufficient plastic strain, and Akhtar and Techtsoonian [4] observed that basal slip is already active at 78 K when the strain is high enough. At much higher temperatures, above 850 K, Akhtar [5] showed that basal slip was the only activated secondary slip system in addition to easy prismatic slip, with the relative ease of basal slip increasing with temperature.…”

Section: Introductionmentioning

confidence: 99%

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Secondary slip of screw dislocations in zirconium

Maras,

Clouet

2021

Preprint

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Plasticity in hexagonal close-packed zirconium is controlled by screw dislocations which easily glide in the prismatic planes where they are dissociated. At high enough temperatures, these dislocations can deviate out of the prism planes to also glide in the first order pyramidal and basal planes. To get a better understanding of these secondary slip systems, we have performed molecular dynamics (MD) simulations of a screw dislocation gliding in a basal plane. The gliding dislocation remains dissociated in the prism plane where it performs a random motion and occasionally cross-slips out of its habit plane by the nucleation and propagation of a kink-pair. Deviation planes are always pyramidal, with an equal probability to cross-slip in the two pyramidal planes on both sides of the basal plane, thus leading to basal slip on average. Basal slip appears therefore as a combination of prismatic and pyramidal slip in the high stress regime explored in MD simulations. This is confirmed by nudged elastic band (NEB) calculations. But NEB calculations also reveal a change of glide mechanism for a decreasing applied stress. At low stress, kinks do not lie anymore in the pyramidal planes. They are now spread in the basal planes, thus fully compatible with a motion of the screw dislocation confined to the basal plane as seen in experiments. Basal slip, which is in competition with pyramidal slip, appears therefore favoured at low stress in pure zirconium.

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“…For the EPSC study, the main objective is to determine which combination of deformation systems will be activated at each step of the plastic deformation path. According to transmission electron microscopy (TEM) observations (Holt & Causey, 1987;McCabe et al, 2006;Long et al, 2015), the EPSC simulation results (Tomé et al, 2001;McCabe et al, 2006;Gloaguen et al, 2007;Beyerlein & Tomé, 2008) and our earlier work (Li et al, 2014), the potential slip modes to accommodate the imposed plastic strain during compression along the three principal directions include prismatic {1010}h1120i (hai type), pyramidal Experimental (Exp.) and calculated (Cal.)…”

Section: Elastic-plastic Self-consistent Model and Parametersmentioning

confidence: 95%

Compression deformation behavior of Zircaloy-4 alloy changing with activated twinning type at ambient temperature: experiment and modeling

Cai

Zhao

et al. 2016

J Appl Cryst

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It is widely accepted that twinning is important for the plastic deformation of zirconium alloys, although the corresponding roles of different types of twinning are rarely discussed. Here, the deformation behavior of Zircaloy-4 alloy at ambient temperature under compression along the rolling, transverse and normal directions of the rolled plate is studied by examination of macroscopic stress-strain curves, texture evolution and in situ lattice strain, combined with elastic-plastic self-consistent simulation. It is concluded that tensile twinning {1012}h1011i, tensile twinning {1121}h1126i and compressive twinning {1122}h1123i are the main deformation twinning types for compression along the three principal directions. A change in the activated twinning type induces differences in the plastic deformation mode and the stress/strain partitioning between parent and child grains. The work provides insight into the effects of deformation twinning on the plastic deformation behavior of Zircaloy-4 alloy.

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Deformation mechanism study of a hot rolled Zr-2.5Nb alloy by transmission electron microscopy. I. Dislocation microstructures in as-received state and at different plastic strains

Abstract: Articles you may be interested inDeformation mechanism study of a hot rolled Zr-2.5Nb alloy by transmission electron microscopy. II. In situ transmission electron microscopy study of deformation mechanism change of a Zr-2.5Nb alloy upon heavy ion irradiation

Cited by 14 publications

References 25 publications

In-situ TEM irradiation creep experiment revealing radiation induced dislocation glide in pure copper

In-situ TEM irradiation creep experiment revealing radiation induced dislocation glide in pure copper

Secondary slip of screw dislocations in zirconium

Compression deformation behavior of Zircaloy-4 alloy changing with activated twinning type at ambient temperature: experiment and modeling

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