Carbon (Graphene/Graphite)

Shabalin, Igor L.

doi:10.1007/978-94-007-7587-9_2

Cited by 31 publications

(12 citation statements)

References 733 publications

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“…Exceptionally rich allotropy is one of the outstanding characteristics of carbon, one niche of which is occupied by amorphous carbons (ACs), or carbon amorphics. Seemingly simple at first glance, the niche covers an extended set of species, both natural and synthetic, among which the former part is rather scarce and is usually presented by soot and coals, including charcoal, whereas the latter is quite rich including black, glassy, and activated carbons, carbon nanofoams, carbide-derived carbon, carbon fibers, diamond-like AC (α-C:H and (ta)-C carbons), and others (see reviews − and references therein). The list of synthetic ACs is constantly increasing as more and more techniques appear to produce these highly requested materials.…”

Section: Introductionmentioning

confidence: 99%

Computationally Supported Neutron Scattering Study of Natural and Synthetic Amorphous Carbons

et al. 2019

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Neutron powder diffraction and inelastic neutron scattering (INS) were used to determine the structure and hydrogen content of basic structure units (BSUs) of sp2 amorphous carbons at the atomic level. A comparative study of two natural (shungite carbon and antraxolite) and two synthetic (carbon blacks) species of the highest-rank carbonization revealed nanosize stack structure of all samples. The stacks are formed by BSUs representing framed graphene molecules (graphene oxyhydrides) of ∼2.5 nm lateral dimension. The INS study showed the presence of hydrogen atoms in the BSU framing area as well as of adsorbed water in the sample pores configured by BSU stacks. Simulated INS spectra of adsorbed water showed its monolayer disposition within the pores. BSU INS spectra were simulated for a set of particular models simulating H-standard features of the INS spectra of graphene-based species, in general, and BSU hydrogen component of the studied samples, in particular. Simulations were performed in the framework of both spin-independent (density functional theory) and spin-dependent (unrestricted Hartree–Fock) molecular vibrational dynamics. The obtained results allowed a reliable presentation of the hydrogeneous component of the BSU atomic structure and proposing a specific INS classification of sp2 amorphous carbons with respect to their hydrogeneousness.

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Section: Introductionmentioning

confidence: 99%

Computationally Supported Neutron Scattering Study of Natural and Synthetic Amorphous Carbons

et al. 2019

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“…The specific heat of powder is taken as that of the solid, as shown in Figure 1(c). In addition, the temperature-dependent mechanical properties such as Young’s modulus, yield stress and thermal expansion coefficient of the solid tantalum taken from literature (Shabalin, 2014; Powell et al , 1968; Škoro et al , 2011; Škoro et al , 2012; Tantalum, 2021) are also given in Figures 1(d)–(f).…”

Section: Modelingmentioning

confidence: 99%

“…Thermo-physical properties of solid (Shabalin, 2014; Powell et al , 1968; Škoro et al , 2011; Škoro et al , 2012; Tantalum, 2021) and powder tantalum materials…”

Section: Figurementioning

confidence: 99%

Modeling SEBM process of tantalum lattices

Yue

et al. 2022

RPJ

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Purpose Selective electron beam melting (SEBM) is one of the popular powder-bed additive manufacturing (AM) technologies. The purpose of this paper is to develop a simulation strategy for SEBM process to get data which are vital for realistic failure prediction and process parameters control for real complex components. Design/methodology/approach Focusing on the SEBM process of tantalum, this paper presents a three-dimensional thermo-mechanical modeling strategy based on ABAQUS and its subroutines. The simulation strategy used in this paper is developed for SEBM process of pure tantalum but could be extended to other AM fabrication technologies and other metals without difficulties. Findings The simulation of multi-track multi-layer SEBM process of tantalum was carried out to predict the temperature field, the molten pool evolution and the residual stress distribution. The key information such as inter-track molten pool overlapping ratio and inter-layer refusion state can be extracted from the obtained molten pool morphologies, which are vital for realistic failure prediction and process parameters control for real components. The authors finally demonstrate the capability of the strategy used by simulating a 2 mm × 2 mm × 10 mm lattice structure with total 200 layers. Originality/value The simulation of multi-track multi-layer SEBM process of tantalum was carried out. The key information such as inter-track molten pool overlapping ratio and inter-layer refusion state can be extracted. The authors finally demonstrate the capability of the strategy used by simulating a lattice structure. Not only temperature distribution but also stress evolution are captured. Our simulation strategy is developed for the SEBM process of pure tantalum, but it could be extended to other AM fabrication technologies and other metals without difficulties.

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“…that root from multiple general families . A similar sp n -based classification is proposed by Shabalin with an additional layer of classification under the sp n families by taking into account relevant data in the literature . Both attempts by Heimann et al and Shabalin are, however, inadequate for differentiating a large structure database like SACADA.…”

Section: Introductionmentioning

confidence: 99%

Quantifying Atomistic Similarity of Carbon Allotropes for Structural Comparison and Classification

Chen

Song

Lau

2021

Crystal Growth & Design

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The expedited discovery of carbon allotropes and the rising attention to novel amorphous carbonaceous solids urge innovations in their effective classification with reference to their structural traits. The present report proposes a new in silico similarity-quantification scheme of carbon allotropes that reflects the exact atomic coordinates via reduction and clustering techniques. It allows for the evaluation of pairwise structural relevance and the fine-grained classification of known carbon allotropes. In practice, 511 known crystalline carbon allotropes are adopted to construct an exemplary training set of the proposed method. Evidently, the resultant taxonomic trees adequately separate structural motifs and group structurally alike allotropes into coherent taxa. In addition, examples are shown to support that mapping external allotropes, both crystalline and amorphous in nature, to their structurally alike counterparts in the training set is effective in revealing structural characteristics of external allotropes.

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Carbon (Graphene/Graphite)

Cited by 31 publications

References 733 publications

Computationally Supported Neutron Scattering Study of Natural and Synthetic Amorphous Carbons

Computationally Supported Neutron Scattering Study of Natural and Synthetic Amorphous Carbons

Modeling SEBM process of tantalum lattices

Quantifying Atomistic Similarity of Carbon Allotropes for Structural Comparison and Classification

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