In-situ TEM study of dislocation-twin boundaries interaction in nanotwinned Cu films

Li, N.; Wang, Jyhpyng; Zhang, X.; Misra, Amit

doi:10.1007/s11837-011-0160-9

Cited by 27 publications

(28 citation statements)

References 40 publications

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“…16 The TEM ability to visualize individual dislocations has been used, notably, to directly observe dislocation motion under tensile loading in the microscope, to elucidate high-temperature plastic deformation mechanisms in materials, 17 and for the detailed study of planar defects such as stacking faults and the interaction of twin boundaries in nanotwinned films. 18 Despite all the valuable information that can be obtained from the atomic structure of, and interfaces between, different materials by TEM, an important consideration that must be kept in mind is that this information comes from a very small portion of material. The TEM sample has to be very thin to be transparent to the electron beam, which limits the visual field to a few micrometers under the best of circumstances.…”

Section: Temmentioning

confidence: 99%

The Use of Ultrasound to Measure Dislocation Density

Barra

Espinoza-González

Fernández

et al. 2015

JOM

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Artículo de publicación ISIDislocations are at the heart of the plastic behavior of materials yet they are very difficult to probe experimentally. Lack of a practical nonintrusive measuring tool for, say, dislocation density, seriously hampers modeling efforts, as there is little guidance from data in the form of quantitative measurements, as opposed to visualizations. Dislocation density can be measured using transmission electron microscopy (TEM) and x-ray diffraction (XRD). TEM can directly show the strain field around dislocations, which allows for the counting of the number of dislocations in a micrograph. This procedure is very laborious and local, since samples have to be very small and thin, and is difficult to apply when dislocation densities are high. XRD relies on the broadening of diffraction peaks induced by the loss of crystalline order induced by the dislocations. This broadening can be very small, and finding the dislocation density involves unknown parameters that have to be fitted with the data. Both methods, but especially TEM, are intrusive, in the sense that samples must be especially treated, mechanically and chemically. A nonintrusive method to measure dislocation density would be desirable. This paper reviews recent developments in the theoretical treatment of the interaction of an elastic wave with dislocations that have led to formulae that relate dislocation density to quantities that can be measured with samples of cm size. Experimental results that use resonant ultrasound spectroscopy supporting this assertion are reported, and the outlook for the development of a practical, nonintrusive, method to measure dislocation density is discussed.Fondecyt 113038

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Section: Temmentioning

confidence: 99%

The Use of Ultrasound to Measure Dislocation Density

Barra

Espinoza-González

Fernández

et al. 2015

JOM

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“…Interfaces act as strong barriers for confining dislocation propagation within layers [1][2][3][4][5][6][7] and transmitting lattice dislocation across interfaces [8][9][10][11][12][13]. As the interface spacing decreases to a few nanometers, experimental characterization using in situ and ex situ transmission electron microscopy [14][15][16][17][18] indicate that lattice dislocations are likely trapped in the interfaces [4,14]. In addition, the stress required for lattice dislocations propagation within layers significantly increases with decreasing layer thickness [19].…”

Section: Introductionmentioning

confidence: 99%

Glide dislocation nucleation from dislocation nodes at semi-coherent {1 1 1} Cu–Ni interfaces

et al. 2015

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a b s t r a c tUsing atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, it is shown that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. Four distinctive node structures were identified: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu-Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces. Under biaxial tension/compression applied parallel to the interface, it is shown that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.

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“…one pair of {111} planes is parallel in the matrix and the twin [11]. CTBs act as strong barriers to slip during plastic deformation, which has been well studied [9][10][11][12][13][14][15][16][17][18][19][20]. The presence of coherent twin boundaries in materials causes abrupt change of crystal orientations across the interface, resulting in the discontinuity of slip systems across twin boundaries, thereby strengthening materials.…”

Section: Introductionmentioning

confidence: 99%

Structure and stability of Σ3 grain boundaries in face centered cubic metals

Wang

Misra

2013

Philosophical Magazine

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AE3 grain boundaries form as a result of either growth twinning or deformation twinning in face centered cubic (fcc) metals and play a crucial role in determining the mechanical and electrical properties and microstructural stability. We studied the structure and stability of AE3 grain boundaries (GBs) in fcc metals by using topological analysis and atomistic simulations. Atomistic simulations were performed for Cu and Al with empirical interatomic potentials to reveal the influence of stacking fault energy on the morphology of the twinned grains. Three sets of tilt AE3 GBs were studied with respect to the tilt axis parallel to h111i, h112i, and h110i, respectively. We showed that AE3{111} and AE3{112} GBs are thermodynamically stable and the others will dissociate into terraced interfaces regardless of the stacking fault energy. The morphology of the nanotwinned grains in Cu is predicted from the above analysis and found to match with experiments.

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In-situ TEM study of dislocation-twin boundaries interaction in nanotwinned Cu films

Cited by 27 publications

References 40 publications

The Use of Ultrasound to Measure Dislocation Density

The Use of Ultrasound to Measure Dislocation Density

Glide dislocation nucleation from dislocation nodes at semi-coherent {1 1 1} Cu–Ni interfaces

Structure and stability of Σ3 grain boundaries in face centered cubic metals

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