• 한국분말재료학회지
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• 제4권1호
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• pp.42-47
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• 1997

It was investigated whether mechanical alloying (MA) processing could be more effective to the formation of metallic composite powder in Cu-C system. Elemental powder mixtures of Cu-70vo1.%C were mechanically alloyed with an attritor in an argon atmosphere and microstructural evolution was examined by X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. It has been found that even with the high volume fraction of immiscible graphite in Cu-C system, the refinement with a few ten nanometer size as well as the highly uniform distribution of copper phases have been achieved by the MA processing.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1225-1226
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• 2006

Particles of high strength material when coated with silver offer a means of obtaining desirable electrical properties and high strength. The coating process employed aqueous ammoniacal silver-nitrate electrolytes with a formaldehyde solution as the reductant. Modifying additives were also applied. The reduction and subsequent deposition of silver occurred selectively on the surface of the tungsten particles. The morphologies of the coated particles were assessed by SEM imaging. The silver was uniformed coated on tungsten powder and its thickness was estimated to be approximately 100nm on the basis of a mass account.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.96-97
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• 2020

In this study, the compressive strength and porosity characteristics of cement mortar mixed with liquid and powder composite water repellent were evaluated. When the liquid water repellent was mixed, the compressive strength at 28 days of age was 42% compared to OPC, and the compressive strength was greatly reduced. However, the 28-day compressive strength of the powder water repellent mixture and P5L1, P6L1 liquid and powder composite water repellent was about 97% compared to OPC, and there was little decrease in compressive strength.

• 한국분말재료학회지
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• 제10권1호
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• pp.21-25
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• 2003

The Sn - graphite composites were prepared by chemical encapsulation method for anode materials in Li-ion batteries. EDS and XRD analysis confirmed the presence of Sn in the graphite structure. Cyclic voltammometry (CV) measurement shows extra reduction and oxidation peaks, which might to be related to the formations of $Li_xSn$ alloy compounds. Graphite-tin composite electrodes demonstrated higher Lithium storage capacities than graphite electrodes. Due to the nature of fine Sn particles on graphite surface, the graphite-tin composite electrodes have shown a good cycle properties.

• 한국분말재료학회지
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• 제15권4호
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• pp.297-301
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• 2008

The Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of mixture of gas-atomized metallic glass powders and ductile brass powders. The successful consolidation of metallic glass matrix composite was achieved by strong bonding between metallic glass powders due to viscous flow deformation and lower stress of ductile brass powders in the supercooled liquid state during spark plasma sintering. The composite shows some macroscopic plasticity after yielding, which was obtained by introducing a ductile second brass phase in the Ni-based metallic glass matrix.

• 한국분말재료학회지
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• 제27권1호
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• pp.14-24
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• 2020

In this work, the electrical explosion of wire in liquid and subsequent spark plasma sintering (SPS) was introduced for the fabrication of Ni-graphite nanocomposites. The fabricated composite exhibited good enhancements in mechanical properties, such as yield strength and hardness, but reduced the ductility in comparison with that of nickel. The as-synthesized Ni-graphite (5 vol.% graphite) nanocomposite exhibited a compressive yield strength of 275 MPa (about 1.6 times of SPS-processed monolithic nickel ~170 MPa) and elongation to failure ~22%. The hardness of Ni-graphite composite had a value of 135.46 HV, which is about 1.3 times higher than that of pure SPS-processed Ni (105.675 HV). In terms of processing, this work demonstrated that this processing route is a novel, simple, and low-cost method for the synthesis of nickel-graphite composites.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1989년도 춘계학술대회 논문집
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• pp.77-80
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• 1989

The aim of the study is to develope the processing technique of PZT-Polymer piezoelectric composite materials for ultrasonic transducer application such as biomedical probe and hydrophone. Piezoelectric composite of PZT and polymer with 1-3 connectivity patterns have been fabricated by dicing-filling method and extrusion forming method. In this study processing forming method. In the study processing steps by extrusion forming method in the preperation of PZT/polymer piezoelectric composites are described. The PZT powder used in the study is commercial powder which is prepared by mixing PbO, TiO$_2$ and ZrO$_2$. The binder, water and plasticizer are mixed with the PZT powder to form a slip. It is necessary to adjust the viescosity of slip according on the PZT rod diameters to be extruded. The electromechanical properties of the piezoelectric composites are characterized in terms of the thickness resonance mode. The pulse response characteristics by the ultrasonic transducer analyzer and osciloscope are evaluated.

• 한국세라믹학회지
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• 제32권1호
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• pp.11-16
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• 1995

High reaction heat evolved from the oxidation of Al was used to synthesize SiC, which might be difficult to be formed by SHS. Al2O3-SiC composite powder was easily manufactured using KNO3 as an ignition and reaction catalyst. Unreacted Si and C were observed after reaction dependent upon the composition of starting powders, reaction atmosphere and relative densities of compacted bodies. The unreacted carbon could be removed by calcining at $600^{\circ}C$ and the remaining Si could be removed by dissolving in NaOH solution. The final powder particles were smaller than 1${\mu}{\textrm}{m}$ in size.

• Journal of Magnetics
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• 제20권2호
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• pp.138-147
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• 2015

The unique nano-scale inter-lamellar microstructure and unparalleled heat treatment process give our developed metal powder composite its outstanding magnetic property for power inductor & motor applications. Compared to the conventional polycrystalline Fe or amorphous Fe-Cr-Si-B alloys, our unique designed inter-lamellar microstructure strongly decreases the intra-particle eddy current loss at high frequencies by blocking the mutual eddy currents. The combination of optimum permeability, magnetic flux and extremely low core loss makes this powder composite suitable for high frequency applications well above 10 MHz. Moreover, it can be also possible to SMC core for high speed motor applications in order to increase the motor efficiency by decreasing the core loss.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.495-496
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• 2006

The kneading process and formulations of feedstock obviously affect the quality of MIM products. In the present work, the rheological behaviour of the composite MIM feedstock, metal matrix (Cu) with few additions of ceramic powders $(Al_2O_3)$, was measured by a self-designed/manufactured simple capillary rheometer. Experimental results show that the distribution between powders and binder is more uniformly when blending time increased. Though high powder loading will increase the feedstock viscosity, the fluidity reveals relatively stable through the load curves of extrusion. Besides, the temperature-dependence of viscosity of the feedstock approximately follows an Arrehnius equation. Basing on Taguchi's method, the kneading optimization conditions and the rheological model of the feedstock were established, respectively.