- Fabrication of Ultra Fine Grained Molybdenum and Mechanical Properties
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Se-Hoon Kim, Young-Ik Seo, Dae-Gun Kim, Myung-Jin Suk, Young-Do Kim
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J Korean Powder Metall Inst. 2010;17(3):235-241.
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DOI: https://doi.org/10.4150/KPMI.2010.17.3.235
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- Mo nanopowder was synthesized by ball-milling and subsequent hydrogen-reduction of MoO_3 powder. To fabricate ultra fine grained molybdenum, two-step sintering and spark plasma sintering process were employed. The grain size of specimen by two-step sintering and spark plasma sintering was around 0.6;µm and 0.4;µm, respectively. Mechanical properties of ultra fine grained Mo with relative density of above 90% were significantly improved at room and high temperatures comparing to commercial bulk Mo of 99% relative density. This result was mainly explained by the grain size refinement due to diffusion-controlled sintering.
- The Formation of Hybridized Porous Structure of Al Alloy by Alkali Surface Modification
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Young-Ik Seo, Young-Moon Kim, Young-Jung Lee, Dae-Gun Kim, Kyu-Hwan Lee, Young-Do Kim
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J Korean Powder Metall Inst. 2009;16(1):22-27.
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DOI: https://doi.org/10.4150/KPMI.2009.16.1.022
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- To improve the filtration efficiency of porous materials used in filters, an extensive specific surface area is required to serve as a site for adsorption of impurities. In this paper, a method for creating a hybridized porous alloy using a powder metallurgical technique to build macropores in an Al-4 wt.% Cu alloy and subsequent surface modification for a microporous surface with a considerably increased specific surface area is suggested. The macropore structure was controlled by granulation, compacting pressure, and sintering; the micropore structure was obtained by a surface modification using a dilute NaOH solution. The specific surface area of surface-modified specimen increased about 10 times compare to as-sintered specimen that comprised of the macropore structure. Also, the surface-modified specimens showed a remarkable increase in micropores larger than 10 nm. Such a hybridized porous structure has potential for application in water and air purification filters, as well as membrane pre-treatment and catalysis.
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Citations
Citations to this article as recorded by  - Development of Vacuum Thin-Film-Forming Mold using Porous Aluminum
Hyung-Sun Kang, Sunghyun Lee
Journal of the Korean Society of Manufacturing Technology Engineers.2020; 29(6): 435. CrossRef - Phosphorus removal from wastewater by ionic exchange using a surface-modified Al alloy filter
Young Ik Seo, Ki Ho Hong, Se Hoon Kim, Duk Chang, Kyu Hwan Lee, Young Do Kim
Journal of Industrial and Engineering Chemistry.2013; 19(3): 744. CrossRef
- Synthesis of Nanostructured Fe-Co Alloy Powders from Metal Salts
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Young-Jung Lee, Jea-Sung Lee, Young-Ik Seo, Young-Do Kim
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J Korean Powder Metall Inst. 2006;13(5):336-339.
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DOI: https://doi.org/10.4150/KPMI.2006.13.5.336
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- Magnetic properties of nanostructured materials are affected in complicated manner by their microstructure such as pain size (or particle size), internal strain and crystal structure. Thus, studies on the synthesis of nanostructured materials with controlled microstructure are necessary fur a significant improvement in magnetic properties. In the present work, nanostructured Fe-Co alloy powders with a grain size of 50 nm were successfully fabricated from the powder mixtures of (99.9% purity) FeCl_2 and CoCl_2 by chemical solution mixing and hydrogen reduction.
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