• Korean Journal of Materials Research
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• v.24 no.10
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• pp.526-531
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• 2014

Thermal shock resistance property has recently been considered to be one of the most important basic properties, in the same way that the transverse-rupture property is important for sintered hard materials such as ceramics, cemented carbides, and cermets. Attempts were made to evaluate the thermal shock resistance property of 10 vol% TaC added Ti(C,N)-Ni cermets using the infrared radiation heating method. The method uses a thin circular disk that is heated by infrared rays in the central area with a constant heat flux. The technique makes it possible to evaluate the thermal shock strength (Tss) and thermal shock fracture toughness (Tsf) directly from the electric powder charge and the time of fracture, despite the fact that Tss and Tsf consist of the thermal properties of the material tested. Tsf can be measured for a specimen with an edge notch, while Tss cannot be measured for specimens without such a notch. It was thought, however, that Tsf might depend on the radius of curvature of the edge notch. Using the Tsf data, Tss was calculated using a consideration of the stress concentration. The thermal shock resistance property of 10 vol% TaC added Ti(C,N)-Ni cermet increased with increases in the content of nitrogen and Ni. As a result, it was considered that Tss could be applied to an evaluation of the thermal shock resistance of cermets.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.106-113
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• 2007

The effect of chemical composition on the microstructural change and tensile property in TRIP-assisted steels with different chemical composition was investigated by using SEM, TEM, XRD and UTM. As a result of microscopic observation, the morphology of retained austenite could be identified as two types : a granular type in a steel containing higher sillicon and a film type in a steel having higher carbon. For the case of higher carbon-containing steel with a tensile strength of 860 MPa and a total elongation of 38%, film-typed retained austenite could be observed between lath bainitic ferrite. Actually, metastable retained austenite was a requisite for the good formability, which means that chemical composition plays a significant role in the microstructure and tensile property of TRIP-assisted steels. With respect to tensile property, the steels containing suitable silicon and manganese, respectively, showed a typical TRIP effect in stress-strain curve, while a steel containing higher manganese content exhibited the assimilar behavior shown in dual phase steel.

• Journal of the Korean institute of surface engineering
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• v.40 no.6
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• pp.245-249
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• 2007

Amorphous IZO films were deposited on PET substrate by DC magnetron sputtering without substrate heating. In order to investigate effect of reactive gas addition on film properties, 0.2-0.4% of $H_2$ or $O_2$ gas was introduced during the deposition. Deposited IZO films were evaluated with mechanical property, electrical property, and water permeability. In the case of $H_2$ gas addition, mechanical property showed clear degradation compared to $O_2$ gas. In the case of $O_2$ gas, water permeability of the IZO film was increased compared to $H_2$ gas which could be attributed to the low adhesion of the film caused by bombardment of high energy negative oxygen ion. As a result, it is confirmed that water permeability of the film could be strongly affected by adhesion of the film.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.252-253
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• 2017

The appearance & spread of new kind of virus might cause national economic shrinkage and reduction of foreign tourist. Finally, severe damage of national economy happens. This research wants that after property analysis for generally applied building interior materials, specifically eco-environmental materials including functional materials are reviewed, classified and their special properties in building were investigated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.120-121
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• 2021

The organic insulation material has excellent thermal insulation property, but it is difficult to expect fire stability, and semi inorganic insulation only delays combustible hour but it is difficult to expect fire stability. In this study, thermal insulation property of cement-based non-combustible inorganic insulation using cement and non combustible materials and redispersible polymer powder was studied. As a result of the experiment, the thermal insulation property decreased as the use of redispersible polymer powder increased, but the heat insulation property improved when using the appropriate amount.

• Textile Coloration and Finishing
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• v.19 no.6
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• pp.35-38
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• 2007

FTriphenylamine dye compound having diheteryl moiety was synthesized and its photoluminescent property was investigated. Organic luminescent materials have received great attentions due to potential application subjects onto full color image displays. In this context, the dye (III) for light emitting materials was synthesized using 2-(4-amino-2-hydroxyphenyl)benzoxazole (I) and 4,4'-diformyltriphenylamine (II). It is well known that the amino groups of compound (I) react with carbonyl groups, especially an aldehyde, to afford azomethine linkages. The dye shows bulish-green fluorescence property, which is anticipated for the light-emitting material for display devices. In this context, our aim is to synthesize diheteryl-substituted triphenylamine fluorescent dye as an emitting material. The spectroscopic characteristics and the fluorescent properties of this dye molecule were examined and determined.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.298-303
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• 2000

We evaluated the electric properties of Bi-2223 jointed tapes processed by both resistive- and supercondcuting-joint methods. For the resistive-joint, filler materials of wood metal, Pb/Sn, In, and silver paste were used, whereas, for the superconductive-joint, the lap joint method were used. In the resistive-joint tape, it was observed that the electrical properties such as current transport property, n-value, and contact resistance of the tape were significantly related to the resistivity of filler materials. On the other hand, in the superconducting-joint tape, the current transport property was dependent on the uniaxial pressure. Specifically, the current transport property varied 50 to 80% with uniaxial pressure, probably due to the irregular microstructure in the transition region.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.29-32
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• 2018

Silkworm powder's thermal property is an important factor for its storage and marketing. This study examined the effect of edible enzyme on the thermal property of silkworm powder using Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Results of the TGA showed that regardless of the enzyme treatment, the weight loss patterns of silkworm powders exhibited 3 step thermal property deterioration at approximately $80^{\circ}C$, $280^{\circ}C$, and $480^{\circ}C$ due to water evaporation and thermal degradation. This is similar with the DSC which also resulted in all samples two endothermic peaks attributed also to water evaporation and thermal degradation. These results indicated that the use of enzyme such as protease and cellulase might not affect significantly the thermal properties of silkworm powder.

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.761-769
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• 2019

In modern societies, people spend most of their time indoors and the temperature and humidity controlled by electrical appliances have a considerable effect on their emotions and health. However, improper operation of the artificial facilities frequently creates substances that are harmful to our body. The importance of controlling the natural humidity of interior materials has therefore attracted significant attention. This study was aimed at quantifying the hygroscopic property of some interior finishing wooden materials. Dried and heat-treated yellow poplar (Liriodendron tulipifera) lumbers, oriented strand board, and plywood were selected for this experiment. The moisture adsorption and desorption rates of wooden materials were measured (ISO 24353). Furthermore, the effects of morphological, physical and chemical factors, such as surface microstructure, roughness, and functional groups, on the hygroscopicity were evaluated. The results of this study should contribute to improved accuracy of hygroscopic-property assessments performed on wooden interior materials.

• Corrosion Science and Technology
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• v.17 no.2
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• pp.81-89
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• 2018

In this study, the effect of Nb alloying element on the corrosion fatigue properties of high strength steel is investigated by conducting fatigue experiments under corrosive condition and hydrogen induced condition, potentiodynamic polarization test, tensile test and surface analyses. Nb element is added to enhance the mechanical property of medium carbon steel. This element forms MX-type phases such as carbides and nitrides which are playing an important role in the grain refinement. The grain refinement is one of the effective way to improve mechanical property because both tensile strength and toughness can be improved at the same time. However, MX-type phase precipitates can be a susceptible site to localized corrosion in corrosive environment due to the potential difference between matrix and precipitate. The obtained results showed that Nb-added steel improved corrosion fatigue property by grain refinement. However, it is degraded for hydrogen-induced fatigue property due to Nb, Ti-inclusions acting as a stronger trap.