Size-Dependent Grain-Boundary Structure with Improved Conductive and Mechanical Stabilities in Sub-10-nm Gold Crystals

Wang, Chunyang; Du, Kui; Song, Kepeng; Ye, Xing-Long; Lü, Qi; He, Suyun; Tang, Dai‐Ming; Lü, Ning; Jin, Hai-Jun; Li, Feng; Ye, Hengqiang

doi:10.1103/physrevlett.120.186102

Cited by 33 publications

(21 citation statements)

References 67 publications

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“…Based on both experimental and simulation results, the transformational misorientations of a disordered GB are in the range of 26-28°among different FCC metals. The dislocation character of GBs can stably exist at almost twice the typical misorientation of 15°defined by the classic description of LAGBs 28 , which can be ascribed to the fact that the structure of high angle GB can transit from the structure unit type to the dislocation type (similar to the classic LAGB) with the decreasing sizes 38 . Nevertheless, the highly organized GB motion is viable as long as the dislocations nature within the GB is retained.…”

Section: Discussionmentioning

confidence: 94%

Metallic nanocrystals with low angle grain boundary for controllable plastic reversibility

et al. 2020

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Advanced nanodevices require reliable nanocomponents where mechanically-induced irreversible structural damage should be largely prevented. However, a practical methodology to improve the plastic reversibility of nanosized metals remains challenging. Here, we propose a grain boundary (GB) engineering protocol to realize controllable plastic reversibility in metallic nanocrystals. Both in situ nanomechanical testing and atomistic simulations demonstrate that custom-designed low-angle GBs with controlled misorientation can endow metallic bicrystals with endurable cyclic deformability via GB migration. Such fully reversible plasticity is predominantly governed by the conservative motion of Shockley partial dislocation pairs, which fundamentally suppress damage accumulation and preserve the structural stability. This reversible deformation is retained in a broad class of face-centred cubic metals with low stacking fault energies when tuning the GB structure, external geometry and loading conditions over a wide range. These findings shed light on practical advances in promoting cyclic deformability of metallic nanomaterials.

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Section: Discussionmentioning

confidence: 94%

Metallic nanocrystals with low angle grain boundary for controllable plastic reversibility

et al. 2020

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“…The GB-precipitate interaction can be understood by modeling GB as an array of GB dislocations [44,45], as presented in Fig. 8b-c. 1) For a = 0°, the cylindrical precipitate is parallel to the GB dislocations, as shown in Fig.…”

Section: Discussionmentioning

confidence: 99%

Grain boundary migration and deformation mechanism influenced by heterogeneous precipitate

Tan

Fang

et al. 2021

J Mater Sci

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Understanding the interaction between heterogeneous precipitates and grain boundaries (GBs) is of great significance for tailoring the stability and mechanical properties of nanograined materials. In this work, the nanoscale interaction between the cylindrical precipitate and the migrating GB is investigated by atomic simulation. The results show that the resistance for GB migration can be increased by decreasing the direction angle $$\alpha$$ α (the angle between the axis of the precipitate and the tilt axis of GB). For the larger precipitate, the influence of direction angle is more pronounced. With the increase in shear strain, the interaction between the specific precipitate and GB changes the material deformation mechanism from “GB migration” to “GB migration accompanied with activated dislocations or GB deformation,” which contributes to the softening of the material. By simultaneously tuning the direction angle and size of heterogeneous precipitates, the GB deformation can be strongly inhibited and the stability of GBs can be significantly improved.

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“…This indicates that conventional GBs are also essential dislocation sources in twin-structural nanograins, which is consistent with MD simulations 16 . To understand why conventional GBs are an important dislocation source, quantitative lattice strain analysis was performed using lattice distortion analysis 49 on the HRTEM images of twin-structural nanograins during the leading process. Figure 6a, b show HRTEM images taken from 2 different twin-structural nanograins captured during the loading process.…”

Section: Discussionmentioning

confidence: 99%

In situ atomic-scale observation of grain size and twin thickness effect limit in twin-structural nanocrystalline platinum

Wang

Yang

et al. 2020

Nat Commun

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Twin-thickness-controlled plastic deformation mechanisms are well understood for submicron-sized twin-structural polycrystalline metals. However, for twin-structural nanocrystalline metals where both the grain size and twin thickness reach the nanometre scale, how these metals accommodate plastic deformation remains unclear. Here, we report an integrated grain size and twin thickness effect on the deformation mode of twin-structural nanocrystalline platinum. Above a ∼10 nm grain size, there is a critical value of twin thickness at which the full dislocation intersecting with the twin plane switches to a deformation mode that results in a partial dislocation parallel to the twin planes. This critical twin thickness value varies from ∼6 to 10 nm and is grain size-dependent. For grain sizes between ∼10 to 6 nm, only partial dislocation parallel to twin planes is observed. When the grain size falls below 6 nm, the plasticity switches to grain boundary-mediated plasticity, in contrast with previous studies, suggesting that the plasticity in twin-structural nanocrystalline metals is governed by partial dislocation activities.

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Size-Dependent Grain-Boundary Structure with Improved Conductive and Mechanical Stabilities in Sub-10-nm Gold Crystals

Cited by 33 publications

References 67 publications

Metallic nanocrystals with low angle grain boundary for controllable plastic reversibility

Metallic nanocrystals with low angle grain boundary for controllable plastic reversibility

Grain boundary migration and deformation mechanism influenced by heterogeneous precipitate

In situ atomic-scale observation of grain size and twin thickness effect limit in twin-structural nanocrystalline platinum

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