• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.677-678
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.477-478
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• 2009

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1703-1711
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• 2000

Microstructural morphology of molded composites of thermotropic liquid crystalline polymer(LCP) and polyamide 6 (PA6) has been studied as a function of epoxy fraction. Injection-moulding of a thin composite plaque at a temperature below the melting point of the LCP fibrils by suing the extruded LCP/PA6 pellets produced multi-layered structures: 1) the surface skin layer with thickness of 65-120 ym exhibiting a transverse orientation, 2) the sub-skin layer with an orientation perpendicular to the surface skin, i.e. in the flow direction, 3) the core layer with arc-curved flow patterns. Similar microstructural orientations were observed in the respective layers for the composite plaques with different fractions of epoxy.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.763-764
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• 2006

Ceramic Injection Moulding (CIM) technology has been successfully used for the fabrication of Mn-Zn Ferrite part. The binder was composed by polypropylene and paraffin wax. The optimal powder loading (58% vol.) was determined by means of rheological measurements. Threedifferent parts, toroids, bending and tensile probes were injected. Thermal and solvent-thermal debinding was designed based on DSC and TGA studies of the binder. The time of the debinding cycle was reduced using n-heptane to dissolve previously the paraffin wax. Final properties have been determined and compared with uniaxial pressure parts values. The densities obtained were slightly higher than those of uniaxial pressure parts and the magnetic properties presented similar values.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1185-1186
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• 2006

In order to obtain specific magnetic properties, it is of paramount importance to increase the alloy density of components fabricated by powder metallurgy. An alternative to increase the density of alloys such as Fe-49Co-2V would be the use of elemental Fe and Co instead of the pre-alloyed powder. Trying to give some insight on the industrial application of this strategy, this paper investigates the replacement of more conventional pre-alloyed Fe-49Co-2V powders with elemental Fe and Co. A previous analysis shows that it is possible to achieve higher densities and leads to a noticeable improvement in some important magnetic properties.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1008-1008
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• 2006

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.213-214
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• 2006

The results of investigations in screw design for metall injection molding (MIM) will be presented. The consistency of cavity pressure, metering time and MFQ (monitoring of feedstock quality; parameter measured during metering) was chosen to compare different screws. A simulation program was used to optimize the conveying and melting mechanisms in the plastification unit. The theoretical background of this simulation programm will be explained.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.883-884
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• 2010

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.589-590
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• 2006

Based on the comparison of structures and properties of the HS6-5-2 high speed steels made with the powder injection moulding method, pressureless forming, compacting and sintering, and commercial steels made with the ASEA-STORA method, fine carbides spread evenly in the steel matrix were found in the structure of all tested high-speed steels in the sintered state. The steels made with the pressureless forming method are characteristic of the lowest sintering temperature and the highest density, resulting from the high carbon concentration coming from the binding agent degradation.

• Electrical & Electronic Materials
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• v.10 no.5
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• pp.440-446
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• 1997

This research has been performed for the fabrication of high quality ferrite plastic magnet. The magnetic properties of S $r_{5.9}$F $e_2$ $O_3$ ferrite bonded magnets by injection moulding with a variety of applied magnetic field were investigated. 0.3wt% CaCO3, 0.2wt% $SiO_2$, 0.5wt% $Al_2$ $O_3$and 0.5wt% N $a_2$ $SiO_3$are added in order to improve the magnetic properties of Sr-ferrite plastic magnets during the powder fabrication. For carbon coating on chemical compound specimen, 5wt% polyvinyl alcohol is added, and then calcinated under $N_2$ environment of 12$25^{\circ}C$. The particle size is distributed from 0.9~1.2${\mu}{\textrm}{m}$ which approximates to the single domain. The obtained Sr ferrite powder is well mixed with silane coupling and calcium stearate of 1wt%. Nest, the specimen is pelleted after kneading each of them with polyamidel2 as a binder. When the temperature of injection and mould were 25$0^{\circ}C$ and 8$0^{\circ}C$ respectively at injection pressure of 200kgf/$\textrm{cm}^2$, the degree of orientation was 85.3% under the applied magnetic field of 12kOe. As the results, when the packing density of Sr ferrite powder was 90wt%, the magnetic properties of Sr ferrite bonded magnet were follows : $_{B}$ $H_{c}$=2.41kOe, Br=3.1kG, (BH)$_{max}$=2.21MgOe. Especially, the Sr-ferrite bonded magnet with 10wt% N $d_2$F $e_{14}$B additive were as follows : $_{B}$ $H_{c}$=2.57kOe, Br=3.14kG and (BH)$_{max}$=2.39MGOe.GOe.GOe.GOe.e.