• 한국분말재료학회지
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• 제23권2호
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• pp.170-176
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• 2016

Lithium-ion batteries (LIBs) are rapidly improving in capacity and life cycle characteristics to meet the requirements of a wide range of applications, such as portable electronics, electric vehicles, and micro- or nanoelectro-mechanical systems. Recently, atomic layer deposition (ALD), one of the vapor deposition methods, has been explored to expand the capability of LIBs by producing near-atomically flat and uniform coatings on the shell of nanostructured electrodes and membranes for conventional LIBs. In this paper, we introduce various ALD coatings on the anode, cathode, and separator materials to protect them and improve their electrochemical and thermomechanical stability. In addition, we discuss the effects of ALD coatings on the three-dimensional structuring and conduction layer through activation of electrochemical reactions and facilitation of fluent charge collection.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1132-1133
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• 2006

Metal-bonded diamond impregnated tools are being increasingly used in the processing of stone and ceramics, road repair, petroleum exploration, etc. Although the main tool wear mechanisms have been identified, the scientific background is inadequate and fundamental research has to be carried out to better understand the tool field behaviour. This work addresses the complex issues of modelling abrasive wear of the metallic matrix under laboratory conditions. The generated data indicates that the matrix wear resistance can be assessed in a simple manner; whereas tests carried out on diamond impregnated specimens may aid prediction of the tool life in abrasive applications.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.756-757
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• 2006

P/M enables the economical production of components for many kinds of gears. Functionally, the sub gear requires high tooth accuracy and bending fatigue strength. The whole tooth profile was sized after sintering to satisfy the gear tooth accuracy specification. The part was redesigned to reduce machining requirements. The required bending fatigue strength was achieved through appropriate material choice and induction of compressive residual stress by shotpeening after carburizing. The P/M sub gear replaced a forged steel gear, satisfied performance requirements, expanded the use of P/M applications and provided over 30% cost reduction.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.792-793
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• 2006

In the paper, the influence of different particle size $D:D>125{\mu}m$, $D<50{\mu}m$ and between on magnetic properties of a standardized dielectromagnetic is presented. The tests were taken at frequencies of between 50Hz, and 500Hz. Presented in the paper results provide important materials property data to allow the selection of the most appropriate dielectromagnetic particle size for different applications.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1319-1320
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• 2006

Several practical applications of melt-textured bulk superconductors require the complex-shaped products such as curved, ring-shaped, and drilled blocks rather than simple shaped pellets. However, melt-textured bulk superconductors are often damaged when they are cut, grinded, or drilled. With the aim of reducing such damages, we have investigated the preparation of the complex-shaped bulk superconductors by previously machining binder-added precursors and pre-sintered precursors. We could produce various complex-shaped bulk superconductors without cracking from these machined precursors

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.234-235
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• 2006

In this study, the plasma sprayed $Al_2O_3$ and $Y_2O_3$ coatings have been investigated for applications of microelectronic components. The plasma sprayed coatings had a well-defined splatted lamellae microstructure, intersplat pores and a higher amount of microcracks within the splats. The plasma sprayed $Y_2O_3$ coating had a relatively lower hardness of 300-400Hv, compared to 650-800Hv for $Al_2O_3$ coating, and would be readily damaged by mechanical attacks such as erosion, wear and friction. For a reactive ion etching against F-containing plasmas, however, the $Y_2O_3$ coating had a much higher resistance than the $Al_2O_3$ coating because of the reduced erosion rate of by-products.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.236-237
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• 2006

Cold spraying is a fairly new coating technique, which within the last decade attracted serious attention of research groups and spray companies. As compared to thermal spraying, the low process temperatures in cold spraying result in unique coating properties, which promise new applications. Since particles impact with high kinetic energy in the solid state, new concepts to describe coating formation are requested to enable the full potential of this new technology. The present contribution gives a brief review of current models concerning bonding, supplying a description of the most influential spray parameters and consequences for new developments. With respect to spray forming by cold cold spraying, microstructures and thick, further machineable structures are presented.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.116-117
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• 2006

Conventional high-speed steels, which are carbide decentralized materials, are used for sliding parts, but they lack sufficient hardness for some applications. Improvement of surface hardness is possible for high-Cr steels through nitriding. However, nitriding P/M parts is not advisable without sealing the porosity before treatment, as they will become brittle. However, it is difficult to seal the pores with steam treatment, because high-Cr steel has a passive film on the surface. Controlling nitriding by decreasing the amount of oxygen on the surface to be nitrided, and grinding to decrease the porosity of the surface, makes it possible to produce a material that has reasonable and sufficient hardness in the required areas.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.66-67
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• 2006

The master sintering curve (MSC) is derived from densification data over a range of heating rates and temperatures. To improve the accuracy, several modifications were proposed: multi-phase MSC for solid state sintering with phase changes, MSC for liquid phase sintering, and MSC with consideration of grain growth. The developed MSC models were applied to several material systems such as molybdenum, stainless steels, and tungsten heavy alloys (WHA), in order to evaluate the effect of compaction pressure, phase change, grain growth, and composition on densification, to classify regions having different sintering mechanism, and to help engineer design, optimize, and monitor sintering cycles.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.132-133
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• 2006

Optimized choice of material for two principally different types of PM components is presented. The first is characterized by high stresses in areas with high stress concentrations (for example synchronizer hubs with very sharp notches, typically <0.25mm in the pre-synchronizer slot and the inner splines). The second type has slightly larger notch radii (small spur gears and sprockets with typically notch radii between 1- 3mm). Diffusion alloyed materials are well suited for sharp notch components. Pre-alloyed materials are also well suited for applications with sharp notches if compressive residual stresses in the notch roots are created by appropriate process control. A free choice of material is available for components with the larger notch radii.