Journal of Powder Materials

Je-Shin Park

9 Articles

Getter Properties of Ti_80-XZr₂₀V_X Alloy Powders: Je-Shin Park, Won-Baek Kim, Chang-Youl Soh, Sung-Wook Cho; J Korean Powder Metall Inst. 2009;16(1):28-32.; DOI: https://doi.org/10.4150/KPMI.2009.16.1.028

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Abstract PDF: The activation temperatures and hydrogen sorption rates of Ti_80-XZr_20V_X alloys were evaluated at room temperature. The alloy powders were prepared by arc melting and then hydride-dehydride(HDH) process. The alloy powders were apt to activate by increase of vanadium in Ti-Zr-V alloys. The easy activation was explained in terms of surface oxygen content which decreased with increase of vanadium on Ti-Zr-V alloys.

The Selective Leaching of Al-Ni Alloy Nano Powders Prepared by Electrical Wire Explosion: Je-Shin Park, Won-Baek Kim, Chang-Youl Suh, Han-Kwon Chang, Jong-Gwan Ahn, Byoung-Kyu Kim; J Korean Powder Metall Inst. 2008;15(4):308-313.; DOI: https://doi.org/10.4150/KPMI.2008.15.4.308

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Abstract PDF: Al-Ni alloy nano powders have been produced by the electrical explosion of Ni-plated Al wire. The porous nano particles were prepared by leaching for Al-Ni alloy nano powders in 20wt% NaOH aqueous solution. The structural properties of leached porous nano powder were investigated by nitrogen physisorption, X-ray diffraction (XRD) and transmission Microscope (TEM). The surface areas of the leached powders were increased with amounts of AI in alloys. The pore size distributions of these powders were exhibited maxima at range of pore diameters 3.0 to 3.5 nm from the desorption isotherm. The maximum values of those were decreased with amounts of Al in alloys.

Fabrication of Porous Nano Particles from Al-Cu Alloy Nano Powders Prepared by Electrical Wire Explosion: Je-Shin Park, Won-Baek Kim, Chang-Youl Suh, Jong-Gwan Ahn, Byoung-Kyu Kim; J Korean Powder Metall Inst. 2008;15(3):234-238.; DOI: https://doi.org/10.4150/KPMI.2008.15.3.234

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Al-Cu alloy nano powders have been produced by the electrical explosion of Cu-plated Al wire. The porous nano particles were prepared by leaching for Al-Cu alloy nano powders in 40wt% NaOH aqueous solution. The surface area of leached powder for 5 hours was 4 times larger than that of original alloy nano powder. It is demonstrated that porous nano particles could be obtained by selective leaching of alloy nano powder. It is expected that porous Cu nano powders can be applied for catalyst of SRM (steam reforming methanol).

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Fabrication of Ni-free Fe-based Alloy Nano Powder by Pulsed Wire Evaporation in Liquid: Part 2. Effect of Solvent and Comparison of Fabricated Powder owing to Fabrication Method
Ho-Jin Ryu, Yong-Heui Lee, Kwang-Ug Son, Young-Min Kong, Jin-Chun Kim, Byoung-Kee Kim, Jung-Yeul Yun
Journal of Korean Powder Metallurgy Institute.2011; 18(2): 112. CrossRef
Fabrication of Ni-free Fe-based Alloy Nano Powder by Pulsed Wire Evaporation in Liquid: Part I. Effect of Wire Diameter and Applied Voltage
Ho-Jin Ryu, Yong-Heui Lee, Kwang-Ug Son, Young-Min Kong, Jin-Chun Kim, Byoung-Kee Kim, Jung-Yeul Yun
Journal of Korean Powder Metallurgy Institute.2011; 18(2): 105. CrossRef

Ag-Cu Powders Prepared by Electrical Wire Explosion of Cu-plated Ag Wires: Won-Baek Kim, Je-Shin Park, Chang-Youl Suh; J Korean Powder Metall Inst. 2007;14(5):320-326.; DOI: https://doi.org/10.4150/KPMI.2007.14.5.320

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Abstract PDF: Ag-Cu alloy nano powders were fabricated by the electrical explosion of Cu-plated Ag wires. Ag wires of 0.2mm diameter was electroplated to final diameter of 0.220 mm and 0.307 mm which correspond to Ag-27Cu and Ag-68Cu alloy. The explosion product consisted of equilibrium phases of alpha-Ag and beta-Cu. The particle size of Ag-Cu nano powders were 44 nm and 70 nm for 0.220 mm and 0.307 mm wires, respectively. The Ag-Cu nano powders contained less Cu than average value due to higher sublimation energy compared to that of Ag. As a result, micron-sized spherical particles formed from liquid droplets contained higher Cu content.

Cu-Ni-P Alloy Nano Powders Prepared by Electrical Wire Explosion: Won-Baek Kim, Je-Shin Park, Chang-Youl Suh, Jae-Chun Lee, Jung-Hwan Kim, Yong-Jun Oh; J Korean Powder Metall Inst. 2007;14(2):108-115.; DOI: https://doi.org/10.4150/KPMI.2007.14.2.108

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Cu-Ni-P alloy nano powders were fabricated by the electrical explosion of electroless Ni plated Cu wires. The effect of applied voltage on the explosion was examined by applying pulse voltage of 6 and 28 kV, The estimated overheating factor, K, were 1.3 for 6 kV and 2.2 for 28 kV. The powders produced with pulse voltage of 6 kV were composed of Cu-rich solid solution, Ni-rich solid solution, and Ni_3P phase. While, those produced with 28 kV were complete Cu-Ni-P solid solution and small amount of Ni_3P phase. The initial P content of 6.5 at.% was reduced to 2-3 at.% during explosion due to its high vapour pressure.

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In-Situ Characterization of Metal Nanopowders Manufactured by the Wire Electrical Explosion Process
Seung-Bok Lee, Jae Hee Jung, Gwi-Nam Bae, Dong-Jin Lee
Aerosol Science and Technology.2010; 44(12): 1131. CrossRef

Synthesis of Zirconium-Based Nanopowder by the Plasma Arc Discharge Process: Gil-Geun Lee, Kyong-Ju Kim, Je-Shin Park; J Korean Powder Metall Inst. 2007;14(1):63-69.; DOI: https://doi.org/10.4150/KPMI.2007.14.1.063

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Abstract PDF: The present study was focused on the synthesis of a zirconium-based alloyed nanopowder by the plasma arc discharge process. The chemical composition, phase structure, particle size and hydrogen sorption property of the synthesized powders under various synthesis conditions were analyzed using XRF, XRD, SEM, XPS and the ASTM-F798 method. The chemical composition of the synthesized Zr-V-Fe-based powders approached that of the raw material with an increasing hydrogen fraction in the powder synthesis atmosphere. The synthesized Zr_55V_29Fe_16 powder consist of a mixed phase structure of the Zr,;ZrH_2,;FeV;and;Zr(V_1-xFe_x)_2 phases. This powder has an average particle size of about 20 nm. The synthesized Zr_55V_29Fe_16 nanopowder showed getter characteristics, even though it had a lower hydrogen sorption speed than the Zr_57;V36;Fe_7 getter powder. However, the synthesized Zr nanopowder with an average particle size of 20 nm showed higher hydrogen sorption speed than the Zr_57;V36;Fe_7 getter powder.

Fabrication of Cu-Zn Alloy Nano Powders by Wire Explosion of Electrodeposited Wires: Won-Baek Kim, Je-Shin Park, Chang-Yeul Suh, Jae-Chun Lee, Yong-Jun Oh, Jeong-Il Mun; J Korean Powder Metall Inst. 2007;14(1):38-43.; DOI: https://doi.org/10.4150/KPMI.2007.14.1.038

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Abstract PDF: Cu-Zn alloy nano powders were fabricated by the electrical explosion of Zn-electroplated Cu wire along with commercial brass wire. The powders exploded from brass wire were composed mainly of alpha,beta,;and;gamma phases while those from electroplated wires contained additional Zn-rich phases as varepsilon, and Zn. In case of Zn-elec-troplated Cu wire, the mixing time of the two components during explosion might not be long enough to solidify as the phases of lower Zn content. This along with the high vapor pressure of Zn appears to be the reason for the observed shift of explosion products towards the high-Zn phases in electroplated wire system.

Changes of Getter properties by Crystallization of Amorphous Zr-V-Ti alloy Powders: Je-Shin Park, Won-Baek Kim, Jin-Sun Baek; J Korean Powder Metall Inst. 2007;14(1):50-55.; DOI: https://doi.org/10.4150/KPMI.2007.14.1.050

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Abstract PDF: The hydrogen sorption speeds of Zr_57V_36Ti_7 amorphous alloy and its crystallized alloys were evaluated at room temperature. Zr_57V_36Ti_7 amorphous alloy was prepared by ball milling. The hydrogen sorption rate of the partially crystallized alloy was higher than that of amorphous. The enhanced sorption rate of partially crystallized alloy was explained in terms of grain refinement that has been known to promote the diffusion into metallic bulk of the gases. The grain refinement could be obtained by crystallization of amorphous phase resulting in the observed increase in sorption property.

Metal Nano Powders as a New Getter Material: Won-Baek Kim, Je-Shin Park, Chang-Youl Suh, Han-Kwon Chang, Jae-Chun Lee, Mi-Young Park; J Korean Powder Metall Inst. 2007;14(1):56-62.; DOI: https://doi.org/10.4150/KPMI.2007.14.1.056

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Abstract PDF: Getter property of nano-sized metallic powders was evaluated as a possible candidate for the future getter material. For the purpose, Ti powders of about 50 nm were prepared by electrical wire explosion. Commercial Ti powders of about 22 micrometer were tested as well for comparison. The room-temperature hydrogen-sorption speed of nano-sized Ti powders was 1.34;L/seccdotcm2 which was more than 4 times higher than that of micron-sized ones. The value is comparable to or even higher than those of commercial products. Its sorption speed increases with activation temperature up to 500°C above which it deteriorates due to low-temperature sintering effect of nano-sized particles.

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