Crystalline structure of detonation synthesized diamonds

Kurdyumov, A. V.; Breusov, O. N.; Дробышев, В. Н.; Mel'nikova, V. A.; Tatsii, V. F.

doi:10.1007/bf00788820

Cited by 5 publications

(7 citation statements)

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“…This phenomenon has often been observed in experiment [1][2][3][4][5][6][7][8][9][10][11] and is a subject of theoretical research including phenomenological studies with EOS (e.g., the BKW) and macrokinetics models [12] and more detailed studies into the physics of carbon condensation in detonation products, its phase states, and kinetics of carbon particle growth/vaporization (see, for example, [13]). …”

Section: Introductionmentioning

confidence: 57%

Molecular dynamics modelling of nanocarbon cluster properties under conditions close to HE detonation

Derbenev

Chizhkova

Sapozhnikov

et al. 2010

EPJ Web of Conferences

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Abstract. We use molecular dynamics for modelling properties of carbon nanoclusters.The size of modelled carbon nanoclusters is below 5 nm, which is typical of detonation diamond nanoclusters. We have found their structural changes at P = 0 to be as follows: Diamond → Diamond core + GL-surface → sandwich-type graphite → Graphite-like liquid. In smaller clusters the transformations start at a lower temperature. Adaptive Template Analysis (ATA) was used to determine the structures. We studied evaporation properties at temperatures above 5000 K. For clusters of several thousands of atoms, the simple dependence k vap ∼ e −T 0 /T /N 1/3 (T 0 is constant) is quite good. It has been found out that densities of saturated vapour for clusters containing from 4000 to 8000 atoms are very close at T = 5000 K. The structure of nanoclusters was studied at nonzero pressures set by an argon environment. Calculated results suggest that the patterns for different temperatures are qualitatively similar for three pressures under study (20, 25 and 30 GPa). At T = 1000-1500 K, the initial diamond core is preserved and a thin disordered GL layer is present on the surface. At T = 2000-5000 K, graphite grains form in the sample and a thin layer of liquid is present on its surface. The sample is amorphous at 5500 K and 6000 K. The prevalence of the graphite phase at these pressures seems to come from the absence of long-range interaction in REBO-2002.

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Section: Introductionmentioning

confidence: 57%

Molecular dynamics modelling of nanocarbon cluster properties under conditions close to HE detonation

Derbenev

Chizhkova

Sapozhnikov

et al. 2010

EPJ Web of Conferences

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“…The above experimental results on the structural state of DALAN diamonds produced from graphite and carbon black and data on DAG and DAS diamonds [26] provide further evidence that detonation synthesis conditions have a great effect on the phase composition, crystal morphology, and degree of dispersion of diamond produced from the starting carbon. Unlike in [26], where the diamond formed from carbon black contained large particles (up to 50 nm), the DALAN diamond investigated in the present work has a homogeneous nanograin (1-3 nm) structure. There are also significant differences in the grain structure of the diamond particles produced from graphite.…”

Section: Dap Type Diamond Powder (Dalan-3)mentioning

confidence: 66%

“…It has been established [22][23][24][25][26] that the graphite → diamond conversion occurs by a martensitic mechanism, and the conversion of carbon black to diamond does not show signs of the martensitic mechanism and has a diffusion nature.…”

Section: Introductionmentioning

confidence: 99%

“…The phase composition of the particles was identified by microdiffraction and interpreted on the basis of known microdiffraction data [25][26][27][28][29][30][31][32]; the substructure of the particles was studied by a dark-field electron microscopy. …”

Section: Introductionmentioning

confidence: 99%

“…Thus, a need has arisen to test in a new way (different from that in [25,26]) the diamond powders of these "new" marks and to study the structural and structural-morphological features of their particles. In this connection, we performed x-ray studies of diamond powders on a DRON-3 setup (using copper and cobalt radiation) and electron-microscopic studies in combination with microdiffraction studies on a JEM-100CX microscope; the results of these studies are reported in the present paper.…”

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confidence: 99%

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Structure and properties of Dalan detonation diamonds

Tatsii

Bochko

Oleinik

2009

Combust Explos Shock Waves

Self Cite

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This paper presents the results of an investigation of the fine crystal structure of Dalan diamonds synthesized from graphite and carbon black by detonation. The phase composition of the diamond powders was found to vary widely; the structural and structural-morphological states of diamond particles were studied. The main types and subtypes of detonation diamonds are characterized according to transmission electron microscopy data. Assumptions are made concerning diamond formation during detonation synthesis. INTRODUCTIONAt present, the production of diamond powders by using detonation synthesis (DS) is of scientific and practical significance. The first is determined by the importance of knowing the physical nature of the formation of nanodispersed diamond particles, and the second is related to the solution of the problem of producing submicron-sized and nanosized diamond powders of uniform particle size. Such powders can be used both as the starting product and to produce nanodispersed ultrahard compact and composite materials.It is known that the detonation synthesis of diamond is based on the two main technological approaches which differ in the nature of the starting nondiamond carbon. The first approach uses the starting carbon in the form of graphite or carbon black [1][2][3][4][5] in a mixture with a high explosive (HE), and the second uses the socalled own carbon formed by the decomposition of a HE. In the second case, mixtures of TNT and RDX are more often used [6][7][8][9]. There is also a third approach to the detonation synthesis of diamond, in which, along with HE, graphite or carbon black, special carbon-containing additives are introduced into the charge to increase the detonation parameters of the charge. In this case, not only graphite or carbon black but also the carbon of the additives is transformed to diamond [10,11]. According to [11], using the third approach, an amorphous diamond-like form of carbon was produced in a significant amount. The diamonds synthesized in [1-5 and 10, 11] using the first approach are referred to by the abbreviations DAG and DAS, and those produced by the third approaches are referred to as DAP; the abbreviations contain information on the nature of the starting carbon and the diamond produced.The diamond synthesized using the second approach (from the carbon of HE molecules) is referred to as ultrafine diamond in the literature. Data on the processes and structural mechanisms of synthesis of this diamond and its properties and regions of application are generalized and discussed in detail in books [12][13][14] and overviews [15][16][17].The detonation synthesis of diamond from graphite and carbon black have been less studied than that of ultrafine diamond, but, nevertheless, the main data on the nature of this process and structural conversions of the starting nondiamond carbon to diamond have been obtained. In particular, the detonation parameters necessary for the synthesis of diamond and the dependence of these parameters on the type of HE, the concentration ...

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