Plastic deformation of Cu single crystals containing an elliptic cylindrical void

Xu, Shuozhi; Su, Yanqing; Chen, Dengke; Li, Longlei

doi:10.1016/j.matlet.2017.02.005

Cited by 33 publications

(10 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Soon after, Tang et al 21 revealed the dislocation mechanism during the void growth and demonstrated the void size effect on the critical stress to initiate plasticity in both face-centered cubic (FCC) and body-centered cubic (BCC) metals. Temperature sensitivity, 22 different stress states and strain rates, 23 void geometry, 24 void in nanowire, 25 and array distribution of void 26 were studied to elucidate the void related plastic deformation or failure mechanism. However, most of the above studies are based on the assumption that there are no other defects around the preexisting voids initially.…”

Section: Introductionmentioning

confidence: 99%

The effects of initial void and dislocation on the onset of plasticity in copper single crystals

Liu

et al. 2019

Journal of Applied Physics

View full text Add to dashboard Cite

Based on molecular dynamics, the effects of void and initial dislocation structure on incipient plasticity are investigated with single crystal copper samples. By introducing a void of different sizes and shapes and dislocations of different initial structures around the void in copper single crystals, we explore their effects on yielding as well as the dominated deformation mechanism. The main findings from this study are as follows: (1) for the samples with a void of the same size, the yield stress approaches to a specific value as the initial dislocation density increases; (2) for samples with a void of varying size, the yield stress becomes independent of the void size as it reaches a certain level, due to the saturation of preexisting dislocations around the void; and (3) as the strain rate increases, the effects of voids and preexisting dislocations on the yield stress become limited due to the response inertia, for which the phase transition from face-centered cubic to an amorphous phase occurs at an extremely high strain rate.

show abstract

Section: Introductionmentioning

confidence: 99%

The effects of initial void and dislocation on the onset of plasticity in copper single crystals

Liu

et al. 2019

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Prior atomistic studies revealed that the nanovoid growth process is affected by many factors, including, but not limited to, strain rate [9], temperature [10], initial porosity [11], initial void shape [12], and crystallographic orientations [13,14,15]. Compared with face-centered cubic (FCC) [1,10,12] and body-centered cubic (BCC) [9,2,11] systems, there exist much fewer studies of nanvoids in metals with a hexagonal close-packed (HCP) lattice, in part due to a lack of reliable interatomic potential and more complicated slip/twinning systems in the latter.…”

Section: Introductionmentioning

confidence: 99%

“…Compared with face-centered cubic (FCC) [1,10,12] and body-centered cubic (BCC) [9,2,11] systems, there exist much fewer studies of nanvoids in metals with a hexagonal close-packed (HCP) lattice, in part due to a lack of reliable interatomic potential and more complicated slip/twinning systems in the latter. Particularly for HCP Mg, the lightest and the third most abundant element in the Earth's crust among all metals, most atomistic simulations in the literature concerned nanocracks [16,17,18,19]; to the best of our knowledge, only a few MD and atomistic-based multiscale studies have been devoted to nanovoids [20,21,22].…”

Section: Introductionmentioning

confidence: 99%

“…Particularly for HCP Mg, the lightest and the third most abundant element in the Earth's crust among all metals, most atomistic simulations in the literature concerned nanocracks [16,17,18,19]; to the best of our knowledge, only a few MD and atomistic-based multiscale studies have been devoted to nanovoids [20,21,22]. Since cracks and voids affect the mechanical behavior of materials differently [23,12], physical understanding of voided materials cannot be obtained by extrapolating from that of cracked ones.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Deformation of periodic nanovoid structures in Mg single crystals

Chavoshi

2018

Mater. Res. Express

Self Cite

View full text Add to dashboard Cite

Abstract. Large scale molecular dynamics (MD) simulations in Mg single crystal containing periodic cylindrical voids subject to uniaxial tension along the z direction are carried out. Models with different initial void sizes and crystallographic orientations are explored using two interatomic potentials. It is found that (i) a larger initial void always leads to a lower yield stress, in agreement with an analytic prediction; (ii) orientations, the two potentials identically predict the nucleation of edge dislocations on the prismatic plane, which then glide away from the void, resulting in extrusions at the void surface; in the case of the smallest initial void, these surface extrusions pinch the void into two voids. Besides bringing new physical understanding of the nanovoid structures, our work highlights the variability and uncertainty in MD simulations arising from the interatomic potential, an issue relatively lightly addressed in the literature to date.

show abstract

“…On the other hand, nanotwinned small‐sized metallic systems, for example, nanopillars and nanotubes, with either parallel or fivefold CTBs, remain relatively lightly explored . Compared with 3D nanocrystals, 1D nanopillars/nanotubes with free surfaces attain additional geometric features including outer/inner diameter and cross‐sectional shape which, along with the CTB spacing, may significantly alter their mechanical properties . On the other hand, deformation may annihilate nanotwins and increase the CTB spacing .…”

mentioning

confidence: 99%

Deformation Mechanisms in Nanotwinned Tungsten Nanopillars: Effects of Coherent Twin Boundary Spacing

Chavoshi

2018

Physica Rapid Research Ltrs

Self Cite

View full text Add to dashboard Cite

Nano-scale coherent twin boundaries (CTBs) significantly alter the mechanical and electrical properties of metallic materials. Despite a number of studies of the nanotwinned nanopillars in face-centered cubic metals, investigations of them in body-centered cubic (BCC) systems are rare. In this Letter, we explore the uniaxial deformation mechanisms of BCC tungsten nanopillars containing nano-scale {112} CTBs using molecular dynamics (MD) simulations. Our work reveals a novel tension-compression asymmetric stress-strain response and deformation behavior, in conjunction with the effects of CTB spacing. With a relatively large CTB spacing, the plastic deformation in nanotwinned nanopillars is mainly controlled by dislocation nucleation from surface/CTB intersections, gliding on distant and adjacent slip planes under tensile and compressive loading, respectively; as a result, the tensile yield stress is almost invariant with respect to the CTB spacing, while the compressive yield stress increases with a decreasing CTB spacing. As the CTB spacing reduces to 1 nm, detwinning, exhibited by annihilation of {112} twin layers as a result of partial dislocations gliding on CTBs, is observed in both tension and compression; at higher strains, however, {111} incoherent twin boundaries, whose resistance to cracking contributes to strain hardening, are formed under tensile loading but not under compressive loading.

show abstract

Plastic deformation of Cu single crystals containing an elliptic cylindrical void

Cited by 33 publications

References 25 publications

The effects of initial void and dislocation on the onset of plasticity in copper single crystals

The effects of initial void and dislocation on the onset of plasticity in copper single crystals

Deformation of periodic nanovoid structures in Mg single crystals

Deformation Mechanisms in Nanotwinned Tungsten Nanopillars: Effects of Coherent Twin Boundary Spacing

Contact Info

Product

Resources

About