Production of Polycrystalline Materials by Sintering of Nanodispersed Diamond Nanopowders at High Pressure. Review

Bochechka, О. О.

doi:10.3103/s1063457618050040

Cited by 5 publications

(6 citation statements)

References 12 publications

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“…As shown in Figure 3 the hardness of NPD sample from sintering nanodiamonds is the lowest (≈100 GPa), which agrees with those reported previously by compacting nanodiamonds. [ 13 ] The hardest sample is from the annealed nanodiamonds with 5% C 60 additive ( H v ∼145 GPa), while the hardness decreases slightly to ≈130 GPa when C 60 additive increases to 10%, but both are harder than the sintered NPD without additive. The results clearly suggest that C 60 additive significantly increases the hardness of the obtained NPD.…”

Section: Resultsmentioning

confidence: 99%

“…To our best knowledge, the NPD samples in the present study exhibit the highest hardness in all the reported NPD materials synthesized by sintering nano/micro-sized diamond crystals under high pressure and high temperature. [13,15] More important, they are significantly harder than SCD and those NPD synthesized from fullerene and glassy carbon by HPHT. [6] For the synthesized NPD samples, more dislocations were created in the nanocrystals of SAND-1 sample during HPHT but the corresponding hardness is the lowest, indicating that the dislocations/structural defects in NPD is not responsible to the high hardness.…”

Section: Weakening Effects Of Nano Amorphous Carbonmentioning

confidence: 99%

“…Sintering of nano/micro‐diamond by HPHT is one of the most important approaches to synthesize polycrystalline diamonds. [ 13 ] The heterogeneous stress distribution within the sample, as a result of the extreme hardness of the raw diamond under HPHT sintering, provides a possible way for the disorder control in NPD by stress relaxation. In the present work, we designed the NPD samples by adding small percentage of fullerene into diamond nanocrystals precursor during HPHT sintering.…”

Section: Introductionmentioning

confidence: 99%

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Super Strengthening Nano‐Polycrystalline Diamond through Grain Boundary Thinning

Yao

Shen

Guo

et al. 2023

Adv Funct Materials

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Introducing nanostructures into diamonds is quite appealing for the synthesis of superhard materials with superior properties. However, as the grain size decreases to nanoscale, grain boundary effects become crucial yet complicated in the nanopolycrystalline diamond (NPD), making it challenging to tailor nanostructures. Here, atomistic simulations are combined with experiment to demonstrate a strengthening strategy for the sintered NPD by introducing thin amorphous grain boundary (AGB). The additive of small percentage of fullerene into precursors during sintering can significantly reduce crushed amorphous‐like nanodomains in diamond nanocrystals, leading to the formation of thin AGB. Such sintered NPD exhibits a significant hardness and fracture toughness enhancement, exceeding that of single crystal diamonds. These atomistic simulations show that upon straining the plastic deformation, crack initiation and propagation in NPD is AGB thickness dependent, and thin AGB can reduce crack nucleation and block crack propagation, well explaining the experimental observations. This study indicates that grain boundary modulation provides a promising approach for rational designs of high‐performance superhard materials with desired high strength.

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Section: Resultsmentioning

confidence: 99%

Section: Weakening Effects Of Nano Amorphous Carbonmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Super Strengthening Nano‐Polycrystalline Diamond through Grain Boundary Thinning

Yao

Shen

Guo

et al. 2023

Adv Funct Materials

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“…The thermodynamically favorable conditions for the formation of graphene layers in decomposition products of explosives and their subsequent consolidation with the formation of monocrystalline graphite particles are implemented at the first stage. The transformation of the latter into a diamond is performed in accordance with the martensite mechanism [ 67 ]. The NCD powders prepared by the detonation synthesis have a small size and are spherical or oval in shape.…”

Section: Synthesis Of Ncdmentioning

confidence: 99%

Application of Nano-Crystalline Diamond in Tribology

Xia

Yang

et al. 2023

Materials

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Nano-crystalline diamond has been extensively researched and applied in the fields of tribology, optics, quantum information and biomedicine. In virtue of its hardness, the highest in natural materials, diamond outperforms the other materials in terms of wear resistance. Compared to traditional single-crystalline and poly-crystalline diamonds, nano-crystalline diamond consists of disordered grains and thus possesses good toughness and self-sharpening. These merits render nano-crystalline diamonds to have great potential in tribology. Moreover, the re-nucleation of nano-crystalline diamond during preparation is beneficial to decreasing surface roughness due to its ultrafine grain size. Nano-crystalline diamond coatings can have a friction coefficient as low as single-crystal diamonds. This article briefly introduces the approaches to preparing nano-crystalline diamond materials and summarizes their applications in the field of tribology. Firstly, nano-crystalline diamond powders can be used as additives in both oil- and water-based lubricants to significantly enhance their anti-wear property. Nano-crystalline diamond coatings can also act as self-lubricating films when they are deposited on different substrates, exhibiting excellent performance in friction reduction and wear resistance. In addition, the research works related to the tribological applications of nano-crystalline diamond composites have also been reviewed in this paper.

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“…Polycrystalline diamond compact (PDC) is a kind of superhard composite composed of a polycrystalline diamond (PCD) layer and carbide substrate [1][2][3][4]. During high pressure and high temperature (HPHT) synthesis processes, a significant diamond-diamond (D-D) bond forms between diamond particles by a dissolution and re-precipitation process, leading to the formation of the PCD layer, which is firmly bonded with the carbide substrate [1,5,6].…”

Section: Introductionmentioning

confidence: 99%

Research on Microstructure, Synthesis Mechanisms, and Residual Stress Evolution of Polycrystalline Diamond Compacts

Ni,

Chen,

Yang

et al. 2023

Crystals

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The microstructure and residual stress of polycrystalline diamond compact (PDC) play crucial roles in the performance of PDCs. Currently, in-depth research is still to be desired on the evolution mechanisms of microstructure and residual stress during high pressure high temperature (HPHT) synthesis process of PDCs. This study systematically investigated the influencing mechanisms of polycrystalline diamond (PCD) layer material design, especially the Co content of the PCD layer, on microstructure and residual stress evolution in PDCs via Raman spectroscopy and finite element micromechanical simulation. The research shows that when the original Co content of the PCD layer is higher than 15 wt.%, the extra Co in the PCD layer will migrate backwards towards the carbide substrate and form Co-enrichment regions at the PCD–carbide substrate interface. As the original Co content of the PCD layer increases from 13 to 20 wt.%, the residual compressive stress of diamond phase at the upper surface center of the PCD layer gradually decreases and transforms into tensile stress. When the original Co content of the PCD layer is as high as 30 wt.%, the residual stress transforms back into significant compressive stress again. The microstructure-based micromechanical simulation at the PCD–carbide substrate interface shows that the Co-enrichment region is the key for the transformation of the residual stress of the diamond phase from tensile stress into significant compressive stress.

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Production of Polycrystalline Materials by Sintering of Nanodispersed Diamond Nanopowders at High Pressure. Review

Cited by 5 publications

References 12 publications

Super Strengthening Nano‐Polycrystalline Diamond through Grain Boundary Thinning

Super Strengthening Nano‐Polycrystalline Diamond through Grain Boundary Thinning

Application of Nano-Crystalline Diamond in Tribology

Research on Microstructure, Synthesis Mechanisms, and Residual Stress Evolution of Polycrystalline Diamond Compacts

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