A Method for an Improvement in the Quality of Diamond Composite Thermostable Material

It is still in focus the problem of obtaining high quality polycrystalline materials by means of sintering fine diamond powders. The most important task of this problem is the consolidation or improvement of the processed polycrystalline diamond. It is worldwide recognized that the plastic deformation of the diamond particles performs the most important role on the diamond powder consolidation. In some cases, the contact and shear tensions reconstruct the compact structure. In this work the sintering process used a mixture of micro and nanodiamonds. The sintering process was carried out in a toroidal high-pressure device. The effects of nanodiamond addition and sintering conditions on the microstructure and mechanical properties sintered diamond bodies were studied. The sintering parameters were pressure of 6.8 GPa and a temperature of 1850 K, and these conditions were maintained for 1 minute. Homogeneous sintered bodies were obtained, which have a Vickers' hardness over 40 GPa, and fracture toughness around 7.1 – 7.9 MPa.m1/2.

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Mechanism of Consolidation of Nanoparticles in Diamond-Boron Oxide System at High Pressure and Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.518.189 ◽

2006 ◽

Vol 518 ◽

pp. 189-194 ◽

Cited By ~ 1

Author(s):

A. Bykov ◽

G. Oleynik ◽

A. Ragulya ◽

I. Timofeeva ◽

L. Klochkov ◽

...

Keyword(s):

High Pressure ◽

Liquid Phase ◽

Boron Oxide ◽

Diamond Powder ◽

Oxide System ◽

Sintering Process ◽

High Pressure And Temperature ◽

Ultradisperse Diamond ◽

High Pressure Sintering ◽

Diamond Powders

The high pressure sintering process of nanocrystalline diamond powder was studied. The influence of the liquid phase on the base of boron oxide was analyzed. The mechanism of cooperative-diffusive coalescence, which acts during sintering of ultradisperse diamond powders, is proposed.

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Liquid Phase Migration during Diamond Powder Sintering by Infiltration Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.450 ◽

2012 ◽

Vol 727-728 ◽

pp. 450-455

Author(s):

Ana Lúcia Diegues Skury ◽

Guerold S. Bobrovinichii ◽

Sérgio Neves Monteiro ◽

Marcia G. de Azevedo ◽

Apostolos Silva

Keyword(s):

Liquid Phase ◽

Initial Mixture ◽

Diamond Powder ◽

Metallic Binder ◽

Powder Sintering ◽

Cutting Inserts ◽

Sintered Diamond ◽

Diamond Powders ◽

Infiltration Method ◽

Petroleum Extraction

Compacts made of sintered diamond powder (DP) are not only extensively used but also essential cutting inserts for operations such as machining metal components or drilling rocks for petroleum extraction. The high pressure and high temperature (HPHT) sintering can be achieved either by an initial mixture of DP with a metallic binder or by first processing the DP at HPHT, which creates a sintered skeleton, followed by the molten metallic binder infiltration. This work investigates the infiltration of Cu, Co and Ni, as binders, into sintered diamond powders with different particles size. It was found that migration of the liquid phase through the sintered diamond skeleton complies with the Darci Law. The penetration coefficient varied from 0.89 x 10-7to 6.41 x 10-7μm2indicating that the migration is affected by several factors.

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Hybrid carbon-hydrocarbon structure

Perspektivnye Materialy ◽

10.30791/1028-978x-2021-9-79-84 ◽

2021 ◽

Vol 9 ◽

pp. 79-84

Author(s):

S. A. Eremin ◽

◽

N. O. Kudryashova ◽

I. A. Leontiev ◽

Y. M. Yashnov ◽

...

Keyword(s):

Synthetic Diamond ◽

Diamond Films ◽

Polycrystalline Diamond ◽

Average Diameter ◽

Diamond Powder ◽

Gas Mixture ◽

Nanocrystalline Graphite ◽

Diamond Powders ◽

Synthetic Diamond Powder ◽

Hybrid Carbon

A new hybrid carbon-hydrocarbon structure was discovered after pumping a gas mixture of methane and hydrogen through 314 – 400 µm synthetic diamond powder. The experiment was carried out on the microwave plasmachemical installation designed for deposition of polycrystalline diamond films. The main parameters during the experiment were the following: the power of the microwave generator 3,5 kW, the flow rate of hydrogen 400 ml/min, methane 20 ml/min, the pressure in the reactor chamber 63 torr. The gas mixture was pumped at pressure drop of 13 torr. The diamond powders were placed in molybdenum cups inserted into a copper pedestal. In the gaps between the diamond particles of the surface layer unidirectional thread-like structures (length 100 – 500 μm, diameter 2 μm) were found, some of which ended in spherical formations (average diameter 18 μm). Such a composition of thread-like structures and spherical formations was called “dandelion” one. Raman spectroscopy was performed to examine the nature of these formations. The thread-like structure was determined as monocrystalline graphite. The surface of the spherical formation was represented by spindle-shaped structures of nanocrystalline graphite (length 2 μm, thickness 200 nm) and nanodiamond grains with trans-polyacetylene chains [C2H2]n.

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Characterization of homoepitaxial diamond films by Electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088713 ◽

1991 ◽

Vol 49 ◽

pp. 880-881

Author(s):

D.P. Malta ◽

S.A. Willard ◽

R.A. Rudder ◽

G.C. Hudson ◽

J.B. Posthill ◽

...

Keyword(s):

Electron Microscopy ◽

Surface Defects ◽

Substrate Surface ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Large Degree ◽

Rf Plasma ◽

Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

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Microstructural Study of Diamond Deformed Under High Pressure and Temperature

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118072 ◽

1985 ◽

Vol 43 ◽

pp. 230-231

Author(s):

E. F. Koch

Keyword(s):

High Pressure ◽

High Temperature ◽

Lattice Structure ◽

Diamond Particle ◽

Polycrystalline Diamond ◽

Sintering Process ◽

Ion Milling ◽

Sintered Compact ◽

Transmission Electron ◽

High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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Iron-Ore Sintering Process Optimization / Optymalizacja Procesu Aglomeracji Rudy Żelaza

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0462 ◽

2015 ◽

Vol 60 (4) ◽

pp. 2895-2900 ◽

Cited By ~ 2

Author(s):

M. Fröhlichová ◽

D. Ivanišin ◽

A. Mašlejová ◽

R. Findorák ◽

J. Legemza

Keyword(s):

Iron Content ◽

Iron Ore ◽

Raw Materials ◽

Size Composition ◽

Sintering Process ◽

Iron Ore Sintering ◽

Iron Ore Sinter ◽

A Charge ◽

Iron Ore Concentrate

The work deals with examination of the influence of the ratio between iron ore concentrate and iron ore on quality of produced iron ore sinter. One of the possibilities to increase iron content in sinter is the modification of raw materials ratio, when iron ore materials are added into sintering mixture. If the ratio is in favor of iron ore sinter, iron content in resulting sintering mixture will be lower. If the ratio is in favor of iron ore concentrate and recycled materials, which is more finegrained, a proportion of a fraction under 0.5 mm will increase, charge permeability property will be reduced, sintering band performance will decrease and an occurrence of solid particulate matter in product of sintering process will rise. The sintering mixture permeability can be optimized by increase of fuel content in charge or increase of sinter charge moisture. A change in ratio between concentrate and iron ore has been experimentally studied. An influence of sintering mixture grain size composition, a charge grains shape on quality and phase composition on quality of the produced iron sinter has been studied.

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Explosive shock synthesis of polycrystalline diamond powders

Shock Waves ◽

10.1007/978-3-642-77648-9_56 ◽

1992 ◽

pp. 367-372 ◽

Cited By ~ 1

Author(s):

S. Fujihara ◽

K. Narita ◽

Y. Saito ◽

K. Tatsumoto ◽

S. Fujiwara ◽

...

Keyword(s):

Polycrystalline Diamond ◽

Diamond Powders

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Effect of Binding and Dispersion Behavior of High-Entropy Alloy (HEA) Powders on the Microstructure and Mechanical Properties in a Novel HEA/Diamond Composite

Entropy ◽

10.3390/e20120924 ◽

2018 ◽

Vol 20 (12) ◽

pp. 924 ◽

Cited By ~ 4

Author(s):

Mingyang Zhang ◽

Wei Zhang ◽

Fangzhou Liu ◽

Yingbo Peng ◽

Songhao Hu ◽

...

Keyword(s):

Mechanical Properties ◽

High Entropy Alloy ◽

Sintering Process ◽

Mixing Processes ◽

High Entropy ◽

Manufacturing Method ◽

Binding Behavior ◽

Constituent Phase ◽

Powder Manufacturing

This study reports the results of the addition of diamonds in the sintering process of a FCC-structured CoCrFeNiMo high-entropy alloy. The effect of raw powder states such as elemental mixed (EM) powder, gas atomization (GA) powder and mechanical alloying (MA) powder on the uniformity of constituent phase was also investigated. Examination of microstructure and evaluation of mechanical properties of the composites depending on the mixing processes were performed. As a result, GA+MA powder composite showed the highest mechanical properties. The experimental results indicated that the powder manufacturing method was an essential parameter to determine the quality of HEA/diamond composites such as the uniformity of phase and binding behavior.

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Iron ore sintering. Part 3: Automatic and control systems

DYNA ◽

10.15446/dyna.v82n190.44054 ◽

2015 ◽

Vol 82 (190) ◽

pp. 227-236 ◽

Cited By ~ 5

Author(s):

Alejandro Cores ◽

Luis Felipe Verdeja ◽

Serafín Ferreira ◽

Íñigo Ruiz-Bustinza ◽

Javier Mochón ◽

...

Keyword(s):

Control Systems ◽

Sintering Process ◽

Iron Ore Sintering ◽

Particle Matter ◽

Automation And Control ◽

Ore Sintering ◽

Productivity Process ◽

And Control ◽

Plant Automation

The sintering process involves a large number of parameters, more than 500, each of which exerts a greater or lesser influence and needs to be controlled, within the possible limits, in order to optimise productivity, process stability, and standardise the composition and quality of the sinter produced. To comply with environmental legislation, a pollution control system must monitor the particle matter and gases generated and emitted into the atmosphere by the sinter plant. Automation and control systems are vital tools to assist plant operators in the monitoring of each stage of the sinter production process.

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