Molecular Dynamics Study on Deformation Mechanism of Grain Boundaries in Magnesium Crystal: Based on Coincidence Site Lattice Theory

Saitoh, Ken-ichi; Kuramitsu, Kohei; Sato, Tomohiro; Takuma, Masanori; Takahashi, Yoshihiro

doi:10.1155/2018/4153464

Cited by 5 publications

(3 citation statements)

References 31 publications

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“…Due to the complexity of the HCP structure, little research has been done on polyMg and its composites. Saitoh et al [13] established grain boundary (GB) models of Mg crystal to study the deformation mechanism under uniaxial tension by the MD method. The results showed that there are significant differences in the deformation mechanisms of GBs from different angles.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Mechanical Properties of Polycrystalline Mg Using Molecular Dynamics Simulation

Liu¹

2022

Computer Modeling in Engineering &Amp; Sciences

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Magnesium (Mg) and its composites have been widely used in different fields, but the mechanical properties and deformation mechanisms of polycrystalline Mg (polyMg) at the atomic scale are poorly understood. In this paper, the effects of grain size, temperature, and strain rate on the tensile properties of polyMg are explored and discussed by the Molecular dynamics (MD) simulation method. The calculated results showed that there exists a critical grain size of 10 nm for the mechanical properties of polyMg. The flow stress decreases with the increase of grain size if the average grain size is larger than 10 nm, which shows the Hall-Petch effect, and the deformation mechanism of large grain-sized polyMg is mainly dominated by the movement of dislocations. When the average grain size is less than 10 nm, it shows the reverse Hall-Petch effect that the flow stress decreases with the decrease of grain size, and the deformation mode of polyMg with small grain-size is the movement and deformation of atoms at the grain boundary. Due to the more active motion of atoms as the system temperature increases, the material can easily reach the plastic stage under tensile loading, and the mechanical properties of polyMg decrease at high temperatures. The strain rate has a hardening effect on the properties of composite. Based on our calculated results, it can provide theoretical guidance for the applications of Mg metal and Mg matrix composites.

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Section: Introductionmentioning

confidence: 99%

Investigation on the Mechanical Properties of Polycrystalline Mg Using Molecular Dynamics Simulation

Liu¹

2022

Computer Modeling in Engineering &Amp; Sciences

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“…The correlation between the (0001) plane of sapphire (Al 2 O 3 ) and (111) plane of NbC was investigated to explain the observation that NbC on c-plane sapphire grows preferentially with the (111) plane. The coincident site lattice (CSL) [31][32][33][34] or domain-matching epitaxy (DME) theory [35][36][37][38] shows that the NbC (111) plane could grow epitaxially on the Al 2 O 3 (0001) plane. Figure 4a, the f value is reduced to 0.16; therefore, an epitaxial growth can be expected.…”

Section: Epitaxial Growth Mechanismmentioning

confidence: 99%

Growth of NbC Thin Film Using CH4 as a Carbon Source and Reducing Agent

Kim

Lee

et al. 2018

Coatings

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Transition metal carbides (TMCs) have high melting points, hardness, and chemical stabilities in acidic media. In this work, a chemical vapor deposition method using CH4 as a carbon source and reducing agent was employed to make an NbC film. NbCl5 carried by Ar gas was used as an Nb precursor. An NbC thin film, deposited on a c-plane sapphire, exhibited a preferential orientation of the (111) plane, which can be explained by domain-matching epitaxy. A nanoindentation test showed that the NbC film with the preferential orientation of the (111) plane was stronger than that with a random orientation. Moreover, the results showed that H2, which is conventionally used as a reducing agent in NbC synthesis, degraded the crystallinity and hardness of the fabricated NbC.

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“…Among these are investigations into pure metals such as sodium [8][9], potassium [10], rubidium [11], and binary metals-alloys [8,12]. Recently, MD simulation technique has become a useful tool to study the mechanical properties and deformation behavior of materials at the nano or atomistic regime [13][14][15]. Heino et al [16], simulated strain on a single Cu crystal for various orientations using MD simulations.…”

Section: Introductionmentioning

confidence: 99%

Atomistic Simulation of the Effect of Temperature on Mechanical Properties of some Nano-Crystalline Metals

Igwe

Batsari

2022

Afr. Sci. Rep.

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For materials with high ductility, malleability and conductivity, temperature will have significant impact on the material properties. This is especially true for pure elemental metals which have a wide range of applications due to their ultrahigh strengths. Recently, the study of damage mechanism at the nano- and micro level has attracted a significant interest and research. However, the current understanding of deformation mechanisms in nanocrystalline metals in relation to atomic structure and behavior is insufficient. In this study, atomistic simulation of uniaxial tension at nano-scale was performed at a fixed rate of loading (500 ms^-1) on some nano-crystalline face centered cubic metals (Al, Cu, and Ni), to study the nature of tensile deformation at different temperatures using the embedded-atomic method (EAM) potential function. The simulation results show a rapid increase in the stress up to a maximum value followed by a sharp drop when the nanocrystal fails by ductile dislocation. The drop in the stress-strain curves can be attributed to the rearrangement of atoms to a new or modified crystalline structure. Additional simulations were run to study the effects of temperature on the stress-strain curve of nano-crystals. The result shows that increasing temperature weakens the ductility of these nanomaterials. In this investigation, the strain corresponding to yielding stress is observed to be lower with increasing temperature. Finally, the evolution of crystalline microstructure during the entire tensile process was investigated. The atomistic simulation result of tensile deformation at nanoscale obtained in this study agree with plasticity phenomenon observed in macroscale.

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Molecular Dynamics Study on Deformation Mechanism of Grain Boundaries in Magnesium Crystal: Based on Coincidence Site Lattice Theory

Cited by 5 publications

References 31 publications

Investigation on the Mechanical Properties of Polycrystalline Mg Using Molecular Dynamics Simulation

Investigation on the Mechanical Properties of Polycrystalline Mg Using Molecular Dynamics Simulation

Growth of NbC Thin Film Using CH4 as a Carbon Source and Reducing Agent

Atomistic Simulation of the Effect of Temperature on Mechanical Properties of some Nano-Crystalline Metals

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