Features of passivation, oxidation and combustion of tungsten nanopowders by air

Kwon, Young Soon; Gromov, A. A.; Ilyin, Alexander P.; Ditts, A. A.; Kim, Ji Soon; Park, Sang Ha; Hong, Moon Hee

doi:10.1016/j.ijrmhm.2004.06.005

Cited by 56 publications

(26 citation statements)

References 15 publications

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“…In the case that a thin passive layer on the particle surface protects the particle from further reaction, a low concentration of the reactive gas can be beneficial (Nalwa, 2003;Karmhag et al, 2001;Sanchez-Lopez et al, 1998;Soon Kwon et al, 2004).…”

Section: Notes On Oxidation Behaviormentioning

confidence: 99%

Generation of nanoparticles by spark discharge

et al. 2008

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Section: Notes On Oxidation Behaviormentioning

confidence: 99%

Generation of nanoparticles by spark discharge

et al. 2008

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“…Ultra-fine powders of various pure metals have been produced by the EWE method. [16][17][18][19][20][21][22] Nevertheless, in the case of alloys and intermetallic alloys, the EWE process has obvious limitations in that the raw materials should be in the form of thin wires with a diameter of less than 1 mm. Because of this difficulty, the EWE method has been applied to only a limited number of alloys.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Fe-Cr-Al Alloy Nanopowders Prepared by Electrical Wire Explosion Process under Liquid Media

et al. 2011

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Fe-Cr-Al alloy nanopowders were successfully prepared by electrical wire explosion method in ethyl alcohol media. The formation of FeCr-Al alloy nanopowder was monitored by X-ray diffraction. The alloy powders have spherical shape and nanometer size. The alloy powders prepared by the electrical wire explosion method have main crystal structures of bcc Fe-Cr alloy. The geometric mean diameter and geometric standard deviation of an alloy powder formed from a wire with diameter of 0.1 mm were 10.2 nm and 1.62, respectively. However, the geometric mean diameter and geometric standard deviation of an alloy powder formed from a wire with diameter of 0.2 mm were 15.4 nm and 1.66, respectively. These values indicate that the particle size of the alloy powders prepared by the EWE method was increased with wire diameter. Fe, Cr, and Al components are uniformly dispersed inside the powder.

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“…The duration of the WEE process is 1-10 µs at a plasma temperature of ∼10 4 K (Kwon et al 2004). Most metallic materials including alloys can be reduced to nanoparticles by the WEE method.…”

Section: Introductionmentioning

confidence: 99%

In-Situ Characterization of Metal Nanopowders Manufactured by the Wire Electrical Explosion Process

Lee

Jung

Lee³

2010

Aerosol Science and Technology

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In order to understand the size distributions of metal nanopowders inside manufacturing equipment operated at elevated pressures, a scanning mobility particle sizer is used to carry out in-situ measurements of metal nanopowders manufactured by the wire electrical explosion process. A pressure reducer and rotating disk diluter are used for conditioning metal nanopowder samples appropriate for real-time aerosol instruments operated at atmospheric pressure. Based on measurement data collected downstream of the evaporation chamber, the production of metal nanopowders shows good stability and uniformity for a total number concentration of approximately 5 × 10 7 particles/cm 3 , and a unimodal size distribution with a mean diameter of approximately 170 nm. Using an aerosol electrometer and two sets of electrostatic classifiers, positively charged particles slightly outnumber negatively charged particles. The performance of the rotating disk diluter is confirmed by comparing the size distributions of metal nanopowders diluted with five different dilution factors, ranging from 235 to 2500. SEM and TEM image analysis indicates that most metal nanopowders manufactured by this process consist of aggregated particles, and their size distributions obtained from SEM images are similar to those measured by the SMPS. The changes in particle size distribution at each stage of the manufacturing process, including the evaporation chamber, trap buffer, cyclone, and mesh filter, are also monitored using the above in-situ monitoring system. The resulting in-situ measurement data can be used for design modifications of equipment, as well as for investigating the sources of nanopowder release to the workplace environment.

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Features of passivation, oxidation and combustion of tungsten nanopowders by air

Cited by 56 publications

References 15 publications

Generation of nanoparticles by spark discharge

Generation of nanoparticles by spark discharge

Characteristics of Fe-Cr-Al Alloy Nanopowders Prepared by Electrical Wire Explosion Process under Liquid Media

In-Situ Characterization of Metal Nanopowders Manufactured by the Wire Electrical Explosion Process

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