Synthesis of metal nitrides and carbide powders by a spark discharge method in liquid media

Sato, Tsugio; Usuki, Kazuyuki; Okuwaki, Akitsugu; Goto, Yasuyuki

doi:10.1007/bf00545471

Cited by 13 publications

(7 citation statements)

References 5 publications

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“…Thus the content of nitrogen in such areas should be less than 20.7 at.% (see the Ti-N phase diagram), that is closer to the 13-18 at.% evaluated from the XRD data. Similar results were obtained in [54,55] for Ti powder synthesized by the spark discharge method in liquid ammonia. The authors claimed that titanium nitride possessing nitrogen defects TiN 1-x (x ∼0.5) was the main product together with small amounts of α-Ti alloyed with nitrogen.…”

Section: Quantitative Phase Analysissupporting

confidence: 85%

“…On the other hand one can assume that the behavior of vapor/liquid Ti during the spark erosion processing should be similar to the behavior typical of the gas atomization method under comparable conditions. C) Comparison of the properties of the spark erosion powder with those obtained by other methods to produce TiN powder [52][53][54][55] is by itself of sufficient interest.…”

Section: Introductionmentioning

confidence: 99%

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Structure and composition of titanium spark erosion powder obtained in liquid nitrogen

Monastyrsky¹,

Ochin²,

WANG³

et al. 2011

Chem. Met. Alloys

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Titanium powders were obtained by the spark-erosion method in liquid nitrogen. As-processed powder particles with typical sizes between 1 and 50 microns have spherical shape. The surface of the Ti powder particles has irregular structure. Many of the micron-sized particles contain irregular holes inside. The inner surface of the holes has well arranged bubble-like structure. The chemical analysis, made by the Kjeldahl method, showed that the powder contains 11.24±0.06 wt.% of nitrogen, while the more reliable XRD method gave 12.4±0.2 wt.%. Backscattering scanning electron microscopy images of cross sections of powder particles, as well as EDX analyses, showed a cellular structure of the particles with nitrogen-rich areas of several microns, separated by relatively thin boundaries of α-Ti(N). The XRD study confirmed that the powder contains about 85 wt.% of the δ-TiN x nitride (osbornite, Fm-3m), 10 wt.% of α-Ti(N) (P6 3 /mmc) and minor quantities of α-and β β β β-Ti (no more than 4 % in total). The TEM investigation showed that particles with sizes between 10 and 100 nm are mainly δ-TiN x nitride, although the quantity of oxygen in the nanoparticles is high. The proposed model for solidification of Ti powder particles considers multiple formation of nuclei of the solid phase on the surface of liquid droplets. It makes it possible to estimate, on the one hand the upper and lower temperatures of the molten droplets that were reached during the spark erosion, and on the other hand the cooling rate, and eventually to specify the mechanism of pore formation inside the powder particles.

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Section: Quantitative Phase Analysissupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Structure and composition of titanium spark erosion powder obtained in liquid nitrogen

Monastyrsky¹,

Ochin²,

WANG³

et al. 2011

Chem. Met. Alloys

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“…It was shown that the discharge between two metal electrodes in liquid nitrogen [21], ammonia [22], and hydrocarbons [23] results in formation of micro-and nanoparticles of metals and their oxides and nitrides. Therewith, such synthesis does not require complicated vacuum systems, which one of its principal advantages.…”

Section: Development Of a Methods For Synthesis Of Nanoparticles In Elmentioning

confidence: 99%

Synthesis and modification of molecular nanoparticles in electrical discharge plasma in liquids

et al. 2015

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A review of studies on the synthesis and modification of nanosized particles by electrical discharges in liquid media is presented. The modern understanding of the mechanisms of initiation and features of discharge evolution in liquids are analyzed. By using of the spectroscopic diagnostics, parameters of the discharge plasma in liquids (water, ethanol) are determined. It is shown that the pulsed electrical discharge between electrodes immersed in a nonconducting or weakly conducting liquid, provides a simple and effective method for the synthesis of nanoparticles of different compositions with the average size ranging from 5 to 50 nm. The morphology, phase structure, and composition of the particles formed are defined by the discharge mode and composition of the liquid medium in which the discharge is produced. The conditions for the synthesis of nanosized metal oxides, carbides, and silicides (for example, copper and zinc oxides, titanium and tungsten carbides, gadolinium silicides) were found. Zinc oxide nanoparticles were produced in pulsed electrical discharge plasma in distilled water, and the possibility of their doping with nitrogen atoms during synthesis was demonstrated. Experimental results on the modification of tungsten and copper powders by spark discharge in ethanol are discussed. The possibility to synthesize copper chalcogenides CuInSe 2 by electrical discharge treatment of a mixture of copper, indium, and selenium powders was demonstrated.wide range of nanomaterials (metals and intermetallics, nitrides, metal oxides and carbides, composite materials).Electrical discharge in liquids is accompanied by a complex of physical and chemical phenomena, including shock wave generation, cavitation processes, formation of a vapor-gas bubble and its pulsation, ionization and decomposition of liquid molecules in the plasma channel and around it, intense UV and sound radiation, and pulsed electric and magnetic fields. These processes generate free radicals, singlet oxygen, ozone, and hydrogen peroxide. Furthermore, electrode erosion results in release into the liquid of atoms and ions of the electrode materials. These excited or ionized particles take part in diverse physicochemical processes that affect the liquid and objects placed in it. A great variety of compounds, including metastable ones, can form in the plasma channel. Nanoparticles are formed by chemical reactions of atoms and ions released from electrodes with the decomposition products of the surrounding liquid.

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“…Other research groups have also reported on arc discharge methods for NM synthesis [147][148][149][150][151][152], with a recent trend in this category of fabricating carbon NM-supported metal NPs for fuel cells application [150,151]. Figure 2(ii-8) shows the spark discharge method [166,167], which involves a spark discharge reaction conducted in an autoclave. Pure metallic plates were used as the electrode, pure metallic pellets with diameters of 2-6 mm as starting materials, and liquid ammonia and n-heptane as dielectric liquid media.…”

Section: Direct Discharge Between Twomentioning

confidence: 99%

Nanomaterial Synthesis Using Plasma Generation in Liquid

Saito

Akiyama

2015

Journal of Nanomaterials

165

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Over the past few decades, the research field of nanomaterials (NMs) has developed rapidly because of the unique electrical, optical, magnetic, and catalytic properties of these materials. Among the various methods available today for NM synthesis, techniques for plasma generation in liquid are relatively new. Various types of plasma such as arc discharge and glow discharge can be applied to produce metal, alloy, oxide, inorganic, carbonaceous, and composite NMs. Many experimental setups have been reported, in which various parameters such as the liquid, electrode material, electrode configuration, and electric power source are varied. By examining the various electrode configurations and power sources available in the literature, this review classifies all available plasma in liquid setups into four main groups: (i) gas discharge between an electrode and the electrolyte surface, (ii) direct discharge between two electrodes, (iii) contact discharge between an electrode and the surface of surrounding electrolyte, and (iv) radio frequency and microwave plasma in liquid. After discussion of the techniques, NMs of metal, alloy, oxide, silicon, carbon, and composite produced by techniques for plasma generation in liquid are presented, where the source materials, reaction media, and electrode configurations are discussed in detail.

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Synthesis of metal nitrides and carbide powders by a spark discharge method in liquid media

Cited by 13 publications

References 5 publications

Structure and composition of titanium spark erosion powder obtained in liquid nitrogen

Structure and composition of titanium spark erosion powder obtained in liquid nitrogen

Synthesis and modification of molecular nanoparticles in electrical discharge plasma in liquids

Nanomaterial Synthesis Using Plasma Generation in Liquid

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