Atomistic simulations of shock waves in cubic silicon carbide

Cheng, Qian; Wu, HengAn; Wang, Y.; Wang, X.X.

doi:10.1016/j.commatsci.2008.10.020

Cited by 9 publications

(3 citation statements)

References 12 publications

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“…The prevention of melting also leads to defending effect of materials. 21,22 Similar phenomenon is obtained for the graphene-nickel target, which suggests a universal strengthening effect of metal composites with graphene interface. To obtain a clear understanding of the underlying mechanism of this effect, we performed a one dimensional simulation model to study the shock response of nanolayered composites as shown in Figures 2(a) and 2(b).…”

supporting

confidence: 69%

Strengthening metal nanolaminates under shock compression through dual effect of strong and weak graphene interface

Liu

Wang

et al. 2014

Applied Physics Letters

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supporting

confidence: 69%

Strengthening metal nanolaminates under shock compression through dual effect of strong and weak graphene interface

Liu

Wang

et al. 2014

Applied Physics Letters

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“…Another factor is the shock wave which might be induced by the high cutting speed. It was reported that the shock wave speed in cubic SiC was ~11.5 km/s, and amorphization would occur when the impact speed exceeded 4.91 km/s [38]. The cutting speed in the MD simulation was much lower than this critical value, and at the same time, the cutting distance was quite short, i.e., ~20 nm, when compared to the length of workpiece, i.e., 300 nm.…”

Section: Experimental Validationmentioning

confidence: 99%

Mechanism of Unstable Material Removal Modes in Micro Cutting of Silicon Carbide

2019

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This study conducts large-scale molecular dynamics (MD) simulations of micro cutting of single crystal 6H silicon carbide (SiC) with up to 19 million atoms to investigate the mechanism of unstable material removal modes within the transitional range of undeformed chip thickness in which either brittle or ductile mode of cutting might occur. Under this transitional range, cracks are always formed in the cutting zone, but the stress states cannot guarantee their propagation. The cutting mode is brittle when the cracks can propagate and otherwise ductile mode cutting happens. Plunge cutting experiment is conducted to produce a taper groove on a 6H SiC wafer. There is a transitional zone between the brittle-cut and ductile-cut regions, which has a mostly smooth surface with a few brittle craters on it. This study contributes to the understanding of the detailed process of brittle-ductile cutting mode transition (BDCMT) as it shows that a transitional range can occur even for single crystals without internal defects and provides guidance for the determination of tcritical from taper grooves made by various techniques, e.g., to adopt larger tcritical around the end of the transitional range to increase machining efficiency for grinding or turning as long as the cracks do not extend below the machined surface.

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“…Numerical studies of nanoindentation on the material has also been carried out [19,23] with an objective to explain the governing deformation mechanisms. There exists other molecular dynamics (MD) simulation of 6H SiC (and/or other polytypes) under various types of complex loading conditions such as nano-cutting [24], nano scratching [23], sliding friction [25], ductile-regime machining [26][27][28] nuclear irradiation [29][30][31] and also shock studies [32][33][34]; however, almost all of these studies (including those in the referred literature of the above mentioned references) were primarily aimed at validating respective experimental results in a global sense rather than providing a detailed local mechanistic study into the cause of microstructural deformation induced in the sample under the applied loading conditions. In the current manuscript, a detailed mechanistic study at the molecular level has been carried out (using numerical diagnostics measures such as radial distribution functions (RDFs), x-ray diffraction as well as phonon vibrations) in which the deformation evolution of the molecules in the sample has been tracked to demonstrate defect nucleation and evolution as pristine samples are subjected to uniaxial loading conditions at room temperature conditions.…”

Section: Introductionmentioning

confidence: 99%

Physics of molecular deformation mechanism in 6H-SiC

Mitra

Ramesh

2023

Modelling Simul. Mater. Sci. Eng.

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Even though there have been several studies in literature of 6H SiC, aproper physics based understanding of the molecular deformation mechanisms of thematerial under different loading conditions is still lacking. Experimentally, the brittlenature of the material leads to difficulties associated with in-situ determination ofmolecular deformation mechanisms of the material under an applied load; whereas,the complex material structure along with the bonding environment prevents propercomputational identification of different types of inelasticity mechanisms within thematerial. Molecular dynamics study (on successful verification of the interatomicpotential with experimental results) of pristine single crystals of 6H SiC have beenused to probe the physics of molecular deformation mechanisms of the material alongwith its inherent orientational anisotropy. The study elucidates the experimentallyobserved mechanisms of defect nucleation and evolution through a detailed analysis ofradial distribution functions, x-ray diffraction as well as phonon vibrational studies ofthe single crystal. Studies have been presented at room temperature, initial hightemperature and different types of confinement effects of the material (includinghydrostatic and different biaxial loading cases). The confinement resulted in anincrease in stress and stiffness whereas increase in initial temperature resulted in adecrease compared to uniaxial stress loading conditions at room temperature.

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Atomistic simulations of shock waves in cubic silicon carbide

Cited by 9 publications

References 12 publications

Strengthening metal nanolaminates under shock compression through dual effect of strong and weak graphene interface

Strengthening metal nanolaminates under shock compression through dual effect of strong and weak graphene interface

Mechanism of Unstable Material Removal Modes in Micro Cutting of Silicon Carbide

Physics of molecular deformation mechanism in 6H-SiC

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