• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1177-1184
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• 2011

Ceramic insert and anchor has many advantages compared with existing steel products, therefor widely applied for concrete bridge, tunnel, railroad and building etc. in Japan. Ceramic insert and anchor start-to-used in Korea is no longer, but the product has already been applied to various construction sites and have been recognized for excellence. But now in Korea, the ceramic insert and anchor are not yet widely use like in Japan. This paper was an introduction to the ceramic insert and anchor, and detailed explained the product excellent performance. Ceramic insert and anchor can be applied to many areas, but in this case the focus was the application of ceramic insert and anchor for railway structures. In this paper we detailed compared the ceramic products with existing steel products in their respective characteristic, and analyzed on their application in domestic and foreign.

• The Korean Journal of Ceramics
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• v.4 no.4
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• pp.340-344
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• 1998

Failure mechanisms were investigated for the two layer thermal barrier coatings consisting of NiCrAlY bond coat and $ZrO_2$-8wt.% $Y_2O_3$ ceramic coating during cyclic oxidation. $Al_2O_3$ developed at the ceramic coating/bond coat interface first, followed by the Cr/Ni rich oxides such as $NiCr_2O_4$ and $Ni(Al, Cr)_2O_4$ during cyclic oxidation. It was observed that the spalling of ceramic coatings took place primarily within the NiCrAlY bond coat oxidation products or at the interface between the bond coat oxidation products and zirconia based ceramic coating or the bond coat. It was also observed that the fracture within these oxidation products occurred with the formation of $Ni(Cr, Al)_2O_4$ spinel or Cr/Ni rich oxides. It was therefore concluded that the formation of these oxides was a life-limiting event for the thermal barrier coatings.

• Journal of Digital Convergence
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• v.11 no.2
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• pp.391-396
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• 2013

As recently highlighted the importance of relationships between people and products, and is a pure functional sensibility in pursuit of the trend. Sensibility factor is an important part in the process of looking to purchase consumer products that suit your sensibilities. The purpose of this study is to look at the possibility of seeing the role and future of the industry to diversify the culture of the ceramic ornaments design sensibility that purpose. Variety of emotional design ceramic ornaments and cultural industries to identify market design induced by craft as cultural products that can stand up to the global process development. Ceramic ornaments of historical, cultural, design, value can be utilized in a variety of cultural industries to offer emotional design ceramic ornaments, ceramic ornaments product design to contribute to the development plan for the purpose.

• Journal of the Korean Ceramic Society
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• v.56 no.6
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• pp.596-600
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• 2019

Artificial intelligence with a sufficient amount of realistic big data in certain applications has been demonstrated to play an important role in designing new materials or in manufacturing high-quality products. To reduce cracks in ceramic products using machine learning, it is desirable to utilize big data in recently developed data-driven optimization schemes. However, there is insufficient big data for ceramic processes. Therefore, we developed a numerical algorithm to make "virtual" manufacturing data sets using indirect methods such as computer simulations and image processing. In this study, a numerical algorithm based on the random walk was demonstrated to generate images of cracks by adjusting the conditions of the random walk process such as the number of steps, changes in direction, and the number of cracks.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.106-111
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• 2005

Failure mechanisms were investigated for the two layer thermal barrier coatings consisting of NiCrAlY bond coat and $ZrO_2-8wt.\% Y_{2}O_3$ ceramic coating during cyclic oxidation. $Al_{2}O_3$ developed at the ceramic coating/bond coat interface first, followed by the Cr/Ni rich oxides such as $NiCr_{2}O_4 and Ni(Al,Cr)_{2}O_4$ during cyclic oxidation It was observed that the spalling of ceramic coatings took place primarily within the NiCrAlY bond coat oxidation products or at the interface between the bond coat oxidation products and zirconia based ceramic coating or the bond coat. It was also observed that the fracture within these oxidation products occurred with the formation of $Ni(Cr,Al)_{2}O_4$ spinel or Cr/Ni rich oxides. It was therefore concluded that the formation of these oxides was a life-limiting event for the thermal barrier coatings.

• Journal of the Korean Ceramic Society
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• v.53 no.4
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• pp.444-449
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• 2016

Industrial by-products generated by integrated iron and steel manufacture cause environmental pollution. The by-products contain not only iron element but also harmful substances. Therefore, in view of to waste recycling and environmental preservation, production of sponge iron using the by-product is considered an effective recycling method. In this study, reduction efficiency of pellets from blast furnace dust was measured. Metallization was found to be increased, as $C/Fe_{total}$ ratio and reaction time were increased. The pellets were formed into a globular shape, and calcined for 60 minutes at $1100^{\circ}C$ in an electric furnace. Phase changes were analyzed using an X-ray diffractometer. Microstructures of the pellets were observed by a scanning electron microscope.

• Carbon letters
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• v.5 no.4
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• pp.164-169
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• 2004

Carbon-ceramic composites refer to a special class of carbon based materials which cover the main drawbacks of carbon, particularly its proneness to air oxidation, while essentially retaining its outstanding properties. In the present paper, the authors report the results of a systematic study made towards the development of C-SiC-$B_4C$ composites, which involves the effects of compositional parameters, namely, carbon-to-ceramic and ceramic-to-ceramic ratios, on the oxidation behaviour as well as other characteristics of these composites. The C-SiC-$B_4C$ composites, heat-treated to $1400^{\circ}C$, have shown that their oxidation behaviour at temperatures of 800~$1200^{\circ}C$ depends jointly on the total ceramic content and the SiC : $B_4C$ ratio. Good compositions of C-SiC-$B_4C$ composites exhibiting zero weight loss in air at temperatures of 800~$1200^{\circ}C$ for periods of 4~9 h, have been identified. Composites with these compositions undergo a weight gain or a maximum weight loss of less than 3% during the establishment of a protective layer at the surface of carbon in a period of 1~6 h. Significant improvement in the strength of C-SiC-$B_4C$ composites has been observed which increases with an increase in the total ceramic content and also with an increase in the SiC : $B_4C$ ratio.

• Journal of Powder Materials
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• v.26 no.6
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• pp.508-514
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• 2019

In the development of advanced ceramic tools, material improvements and design freedom are critical in improving tool performance. However, in the die press molding method, many factors limit tool design and make it difficult to develop innovative advanced tools. Ceramic 3D printing facilitates the production of prototype samples for advanced tool development and the creation of complex tooling products. Furthermore, it is possible to respond to mass production requirements by reflecting the needs of the tool industry, which can be characterized by small quantities of various products. However, many problems remain in ensuring the reliability of ceramic tools for industrial use. In this study, alumina inserts, a representative ceramic tool, was manufactured using the digital light process (DLP), a 3D printing method. Alumina inserts prepared by 3D printing are pressurelessly sintered under the same conditions as coupon-type specimens prepared by press molding. After sintering, a hot isostatic pressing (HIP) treatment is performed to investigate the effects of relative density and microstructure changes on hardness and fracture toughness. Alumina inserts prepared by 3D printing show lower relative densities than coupon specimens prepared by powder molding but indicate similar hardness and higher fracture toughness values.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.5
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• pp.256-262
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• 2017

Digital ink-jet printing technology using ceramic ink, which is thermally stable at high temperature above $1000^{\circ}C$, has an advantage of eco-friendly process applicable to manufacturing products with an excellent durability and various designs. Recently, replacement from conventional manufacturing process to digital process using ink-jet printing technique has been significantly accelerated in ceramic tile industry. In this study, we investigated ink-jet printability of ceramic ink on ceramic tile. Cyan, magenta, yellow, black ceramic inks, which are digital primary color of ink-jet printing, were printed on glazed surface of ceramic tiles, and their printabilities were comparatively analyzed. High temperature sintering process is generally required for manufacturing ceramic products, thus effect of sintering process on printed pattern of ceramic ink was also investigated by analyzing ink penetration depth and ink dot area.

• Korean Journal of Materials Research
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• v.20 no.4
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• pp.181-186
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• 2010

Since it was developed by Joseph Aspdin, cement has been a common construction materials up to the present time. However, there are trace constituents in cement clinker. One of the trace constituents included in cement clinker, chromium, has become prominent and highly noticed lately as a social issue both inside and outside of this country because it affects the human body negatively. The aim of the present study was to investigate the concentration of water-soluble hexavalent chromium in cement clinker by using industrial by-products. For that reason, raw materials were prepared to add different $SiO_2$, $Al_2O_3$, and $Fe_2O_3$ sources. After the raw materials such as the limestone, the sand and the clay, iron ore was pulverized and mixed, and the raw meal was burnt at about $1450^{\circ}C$ in a furnace with an oxidizing atmosphere. The part in the raw materials of the clinker was substituted with slag, sludge, etc. and this was used to manufacturing cement clinker. To investigate the water-soluble hexavalent chromium content in clinker, raw meal was prepared by changing the modulus, the type, and the content of clinker materials and tested concentrations of hexavalent chromium in the clinkers. To determine $Cr^{+6}$ formation of the clinker, tests were done with raw meals adding chromium by using different industrial by-products. Consequently because the chromium was to be included in the raw materials of the clinker, production of Portland cement clinker was included with the chromium. Also, the chromium was converted into hexavalent chromium in the burning process.