• 한국세라믹학회지
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• 제55권5호
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• pp.440-445
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• 2018

To control the electrical properties of a SiC heating element, we sintered $SiC-ZrB_2$composites by using the spark plasma sintering method. The addition of $ZrB_2$ particles with lower electrical conductivity to the SiC matrices with comparatively higher electrical resistivity lowers the electrical resistivities of the composite material. The $ZrB_2$ particles aggregate to form large particles and 3-1, 3-2, and 3-3 networks, i.e., conduction paths. In our study, about $1-{\mu}m$-sized $ZrB_2$ powders start to form the conduction path at about 10 vol.% of addition, namely the threshold volume. The Joule heating experiment shows that 20 vol.% $ZrB_2$-added SiC heating element has outstanding heating efficiency.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1205-1206
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• 2006

Dispersion-strengthened copper with $TiB_2$ was produced by ball-milling and spark plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at $650^{\circ}C$ for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from 93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased, while the electrical conductivity decreased. On the other hand, hardness decreased with increasing sintering temperature, but the electrical conductiviey increased slightly

• 한국세라믹학회지
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• 제49권2호
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• pp.173-178
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• 2012

The $Y_2O_3$ ceramics have been widely used as plasma resistant materials in the semiconductor industry. In this study, composites made of plasma resistant $Y_2O_3$ and electrically conductive carbon have been produced. The electrical properties of this composite were measured with respect to the size, volume fraction of the conductive carbon phase, and sintering temperature. When micro-sized carbon was used, the composites were insulating up to 5 wt% addition of the carbon. However, when nano-sized carbon of around 60 ~100 nm was used, the composites became conductive over threshold volume fraction of carbon, which increased with increasing sintering temperature. This behavior of electrical conductivity of the composites was discussed in terms of the percolation theory. The percolation threshold of the conductivity seemed to be affected by the grain growth and coalescences of dispersed conductive carbon phases with grain growth of matrix $Y_2O_3$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.220-223
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• 1988

A the dependent model for wail-stabilized local thermodynamic equilibrium (LTE) arcs has been used to examine the high-pressure sodium vapor arc. Arc properties including temperature, electrical conductivity, and optically thick and optically thin radiation fluxes were calculated as functions of radius and time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1636-1638
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• 1996

MMA-Styrene-Tetramethyltin(MST) thin films were fabricated by plasma polymerization method, and their electrical properties were confirmed by IR and GPC. The electrical conductivity increased with increasing temperature, and the adsorption current hardly appeared. The high-field electrical conduction mechanism is the electronic one such as schottky, and the activation energy is about 1.1 eV.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.523-524
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• 2006

The $TiB_2$ dispersion strengthened copper alloy was attracted as thermal and electrical functional material for the high mechanical strength, high thermal stability and good conductivity of $TiB_2$. In the present study, the focus is on the synthesis of $TiB_2$ dispersed copper alloy by spark plasma sintering process using copper oxide and titanium diboride as raw materials. The mechanical, thermal and electrical properties of sintered bodies were discussed with the sintering parameters, and developed microstructure and phase of sintered bodies.

• 한국분말재료학회지
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• 제24권2호
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• pp.115-121
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• 2017

In this work, p-type Bi-Sb-Te alloys powders are prepared using gas atomization, a mass production powder preparation method involving rapid solidification. To study the effect of the sintering temperature on the microstructure and thermoelectric properties, gas-atomized powders are consolidated at different temperatures (623, 703, and 743 K) using spark plasma sintering. The crystal structures of the gas-atomized powders and sintered bulks are identified using an X-ray diffraction technique. Texture analysis by electron backscatter diffraction reveals that the grains are randomly oriented in the entire matrix, and no preferred orientation in any unique direction is observed. The hardness values decrease with increasing sintering temperature owing to a decrease in grain size. The conductivity increases gradually with increasing sintering temperature, whereas the Seebeck coefficient decreases owing to increases in the carrier mobility with grain size. The lowest thermal conductivity is obtained for the bulk sintered at a low temperature (603 K), mainly because of its fine-grained microstructure. A peak ZT of 1.06 is achieved for the sample sintered at 703 K owing to its moderate electrical conductivity and sustainable thermal conductivity.

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.516-521
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• 2016

Mo-Cu alloys have been widely used for heat sink materials, vacuum technology, automobile, and many other applications due to their excellent physical and electric properties. Especially, Mo-Cu composites with 5 ~ 20 wt.% copper are widely used for the heavy duty service contacts due to their excellent properties like low coefficient of thermal expansion, wear resistance, high temperature strength, and prominent electrical and thermal conductivity. In most of the applications, highly-dense Mo-Cu materials with homogeneous microstructure are required for better performance. In this study, Mo-Cu alloys were prepared by PBM (planetary ball milling) and SPS (spark plasma sintering). The effect of Cu with contents of 5~20 wt.% on the microstructure and thermal properties of Mo-Cu alloys was investigated.

• 전기학회논문지
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• 제66권11호
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• pp.1600-1604
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• 2017

Mo-Cu alloys have been widely used for heat sink materials, vacuum technology, automobile and many other applications due to their excellent physical and electronic properties. Especially, Mo-Cu composites with 5~20 wt% copper are widely used for the heavy duty service contacts due to their excellent properties like low coefficient of thermal expansion, wear resistance, high temperature strength and prominent electrical and thermal conductivity. In most of the applications, high dense Mo-Cu materials with homogeneous microstructure are required for high performance, which has led in turn to attempts to prepare ultra-fine and well-dispersed Mo-Cu powders in different ways, such as spray drying and reduction process, electroless plating technique, mechanical alloying process and gelatification-reduction process. However, most of these methods were accomplished at high temperature (typically degree), resulting in undesirable growth of large Cu phases; furthermore, these methods usually require complicated experimental facilities and procedure. In this study, Mo-Cu alloying were prepared by planetary ball milling (PBM) and spark plasma sintering (SPS) and the effect of Cu with contents of 5~20 wt% on the microstructure and properties of Mo-Cu alloy has been investigated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.187-190
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• 2009

$LaCrO_3$ series are the most common candidate materials for a ceramic interconnect for SOFC and the thermal expansion coefficient of these matches very well with that of YSZ electrolyte. In this study, characteristics of the coated films on the anode-support, which were formed by using $La_{0.8}Ca_{0.2}CrO_3$, $La_{0.8}Sr_{0.2}CrO_3$, $La_{0.8}Ca_{0.2}Co_{0.1}Cr_{0.9}O_3$ for ceramic interconnet for SOFC, were investigated. All powders showed single perovskite phase and the precursors had spherical shapes of $2{\mu}m{\sim}30{\mu}m$. According to SEM analysis, coated film of LCC on pretreated anode-support was more thicker, whereas the coated film on untreated anode-support was densely formed. As the results of electrical conductivity of anode-support coated with the ceramic interconnects, LCCC exhibited the most excellent electrical conductivity of 0.15S/cm at $750^{\circ}C$.