• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1995.11a
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• pp.5-5
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• 1995

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.04a
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• pp.54-55
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• 2003

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.675-675
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• 2006

• Bulletin of the Korean Chemical Society
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• v.21 no.3
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• pp.336-338
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• 2000

• Journal of Powder Materials
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• v.20 no.6
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• pp.411-424
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• 2013

In this study, the synthesis of nickel nanoparticles and copper nanospheres for the potential applications of MLCC electrode materials has been studied by plasma arc evaporation method. The change in the broad distribution of the size of nickel and copper nanopowders is successfully controlled by manifesting proper mixture of gas ambiance for plasma generation in the size range of 20 to 200 nm in diameter. The factors affecting the mean diameter of the nanopowder was studied by changing the composition of reactive gases, indicating that nitrogen enhances the formation of larger particles compared to hydrogen gas. The morphologies and particle sizes of the metal nanoparticles were observed by SEM, and ultrathin oxide layers on the powder surface generated during passivation step have been confirmed using TEM. The metallic FCC structure of the nanoparticles was confirmed using powder X-ray diffraction method.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.794-795
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• 2006

Metal powder for dust core application was developed. The powder can be produced improved high-pressure water atomization process. The process has produced powder of spherical shape and lower coercivity. The dust core obta ined shows lower core loss.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.712-713
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• 2006

We successfully developed Al-Si-Transition Metal (TM) -Rare Earth (RE) Powder Metallurgy (P/M) alloy with fine microstructure, which has high strength at high temperature. This material was compacted rapidly solidified powder and directly consolidated by hot extruding or forging. Before consolidating, rapid heating was performed on powder compaction in order to keep the fine microstructure in powder state. We have also investigated the processing conditions of this new alloy by computing simulations and experiments.

• Transactions of Materials Processing
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• v.15 no.5 s.86
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• pp.360-365
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• 2006

Carbon nanotubes (CNTs) have been the subject of intensive studies for applications in the fields of nano technologies in recent years due to their superior mechanical, electric, optical and electronic properties. Because of their exceptionally small diameters (${\appros}\;several\;nm$) as well as their high Young's modulus (${\appros}1\;TPa$), tensile strength (${\appros}\;200\;GPa$) and high elongation (10-30%) in addition to a high chemical stability, CNTs are attractive reinforcement materials for light weight and high strength metal matrix composites. Although extensive researches have been performed on the electrical, mechanical and functional properties of CNTs, there are not many successful results on the mechanical properties of CNT dispersed nanocomposites. In this paper, we applied equal channel angular pressing for consolidation of CNT/Cu powder mixtures. We also investigated the hardness and microstructures of CNT/Cu nanocomposites used experimental for metal matrix composites.

• Journal of Powder Materials
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• v.10 no.5
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• pp.310-317
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• 2003

Two-component ceramic (alumina-zirconia) composites were fabricated by a soft-solution process in which polyethylene glycol (PEG) was used as a polymeric carrier. Metal salts and PEG were dissolved in ethyl alcohol without any precipitation in 1:1 volume ratio of alumina and zirconia. In the non-aqueous system, the flammable solvent made explosive, exothermic reaction during drying process. The reaction resulted in formation of volume expanded, porous precursor powders by a vigorous decomposition of organic components in the precursor sol. The PEG content affected the grain size of sintered composites as well as the morphology of precursor powders. The difference of microstructure in sintered composite was attribute to the solubility and homogeneity of metal cations in precursor sol. At the optimum amount of the PEG polymer, the metal ions were dispersed effectively in solution and a homogeneous polymeric network was formed. It made less agglomerated particles in the precursor sol and affected on uniform grain size in sintered composite.

• Journal of Powder Materials
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• v.21 no.2
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• pp.142-146
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• 2014

Fundamental experiences have been studied for development of pre-treatment process of Sn by-products such as solders. Dry and wet separation/recovery processes were considered by the differences of physical properties. The by-products, which are analyzed by solder metal and oxides. The metal and oxide were simply separated by dry ball-milling process for 12 hours, after that recovery metal powder might be reusable as lead or lead-free solders. In terms of wet separation process, samples were dissolved in $HNO_3+H_2O_2$ and the precipitation were analyzed by $SnO_2$. Overall efficiency of recovery might be increasing via developing simple pre-treatment process.