• The Transactions of the Korean Institute of Electrical Engineers
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• v.44 no.6
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• pp.799-805
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• 1995

An infrared radiator of cordierite system were manufactured byslurry casting anddry pressing method. The characteristics of cordierite (2MgO.2Al$_{2}$O$_{3}$.5SiO$_{2}$)+30wt% clay+Xwt% MnO$_{2}$ of infrared radiator have been investigated as a function of MnO$_{2}$ additives (X=0, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5). The thermal expansioncoefficient was decreased with increasing amounts of MnO$_{2}$ additives. Otherwise, the spectral emissivity was increased in the below 4.5.mu.m wavelength. Also, the infrared radiator of cordierite system which spectral emissivity was approximately 1.0 can be attainable at from 4.5.mu.m to 8.mu.m wavelength. The spectral emissivity was decreased from 8.mu.m to 14.mu.m above X=2.5.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.133-137
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• 1994

Infrared radiator of Cordierite system were manufactured using Cordierite(2Mgo$.$2Al$_2$O$_3$$.$5SiO$_2$) and Clay 30wt% as main materials and addition of MnO$_2$ from 0. 1 to 2 5wt% of Dry pressing and slip casting The effects of MnO$_2$ additives on the thermal properties of infrared radiator of Cordierite system. The more the thermal expansion could be lowered the more the amount (wt%) of additives MnO$_2$is increased in the below 4.5$\mu\textrm{m}$. The high efficiency Infrared radiator of Cordierite system using dry pressing method when the amount of additives MnO$_2$is 2.0 wt%

• Journal of the Korean Ceramic Society
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• v.32 no.7
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• pp.769-776
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• 1995

Infrared radiators of a cordierite system [cordierite (2MgO.2Al2O3.5SiO2)＋30wt% clay＋X wt% MnO2 (X=0, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5)] were manufactured by a slurry casting method. Thermal and physical properties of these infrared radiators were studied by the measurement of spectra emissivity, thermal expansion coefficient and apparent density, SEM and EPMA analyses were also carried out. The thermal expansion coefficient and apparent density were decreased with increasing amouonts of MnO2 additives. On the other hand, the spectral emissivity was increased in the wavelength below 4.5${\mu}{\textrm}{m}$. Also, infrared radiators of the cordierite system, of which the spectral emisivity was 0.8, could be attainable in the wavelength above 4.5${\mu}{\textrm}{m}$. The infrared radiator of the cordierite system with 2.0wt% MnO2, of which the spectral emissivity was approximately 1.0, could be attainable in the wavelength between 4.5${\mu}{\textrm}{m}$ and 8${\mu}{\textrm}{m}$. The spectral emissivity of the specimen containing 2.0wt% MnO2 was higher than others in the wavelength between 8${\mu}{\textrm}{m}$ and 14${\mu}{\textrm}{m}$.

• Journal of the Korean Ceramic Society
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• v.31 no.9
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• pp.975-980
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• 1994

The thermal properties of cordierite (2MgO.2Al2O3.5SiO2)+30 wt% clay+ Xwt% MnO2 of infrared radiator have been investigated as a function of MnO2 additives (X=0,0.1,0.25,0.5,1.0,1.5,2.0,2.5). The thermal expansion coefficient was decreased with increasing amounts of MnO2 additives. Otherwise, the spectral emissivity was increased in the below 4.5 ${\mu}{\textrm}{m}$ wavelength. Also, the infrared radiator of cordierite system which spectral emissivity was approximately 1.0 can be attainable at from 4.5 ${\mu}{\textrm}{m}$ to 8 ${\mu}{\textrm}{m}$ wavelength. The spectral emissivity was decreased from 8 ${\mu}{\textrm}{m}$ to 14 ${\mu}{\textrm}{m}$ above X=2.5.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.27-30
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• 2003

In order to get the infrared ray radiator with high efficiency emission, the starting raw material $Fe_2O_3$ powder is heat-treated under the oxygen pressure log[$PO_2$] = -13~15 at $800^{\circ}C$ for 2hours. It has shown that the radiation rate was larger than 0.85 at the relatively high temperature($400^{\circ}C$), and decreased slowly with increasing the temperature from 50 to $400^{\circ}C$.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1317-1319
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• 1994

The thermal properties of Cordierite$(2MgO.2Al_2O_3.5SiO_2)$ + 30 [wt%]clay + X[wt%]MnO_2$ of infrared radiator have been investigated as a function of $MnO_2$ additives (X=0, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5). The thermal expansion coefficient was decreased and the spectral emissivity was increased only in the below $4.5{\mu}m$ wavelength with increasing amaunts(wt%) of $MnO_2$ additives. Also, the infrared radiator of Cordierite system which spectral emissivity was approximately 1.0 can be attainable at from $4.5{\mu}m$ to $8{\mu}m$ wavelength. The spectral emissivity was decreased from $8{\mu}m$ to $14{\mu}m$ at X=2.5.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.225-228
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• 2000

Addition effects of metal oxide on the characteristics of infrared radiator of porous cordierite have been investigated. The porosity was increased with adding the graphite for 2MgO $.$ 2A1$_2$O$_3$$.$5SiO$_2$. The microstructure and the spectral emissivity were investigated as a function of metal oxide additives. The prosity and the emissivity were decreased with increasing amounts of CuO additives. The prosity and the emissivity were increased with increasing amounts of CoO, MnO$_2$ additives. The infrared radiator of cordierite system which spectral emissivity was 0.927 and 0.928 at from 5$\mu\textrm{m}$ to 20$\mu\textrm{m}$ wavelength as a 9wt% of CoO and MnO$_2$ additives.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.336-341
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• 2013

In this paper, the design concept of a low-temperature vacuum blackbody was described, and thermophysical model of the blackbody was numerically evaluated. Also the working performance of low-temperature vacuum blackbody was evaluated using infrared camera system. The blackbody system was constructed to operate under high-vacuum conditions ($2.67{\times}10^{-2}$ Pa) to reduce temperature uncertainty, which is caused by vapor condensation at low temperatures usually below 273 K. In addition, both heat sink and heat shield including cold shield were installed around radiator to prevent heat loss from the blackbody. Simplified mathematical model of blackbody radiator was analyzed using modified Stefan-Boltzmann's rule. The infrared radiant performance of the blackbody was evaluated using infrared camera. Based on the results of measurements, and simulation, temperature stability of the low-temperature vacuum blackbody demonstrated that the blackbody system can serve as a highly stable reference source for the calibration of an infrared optical system.

• Korean Journal of Materials Research
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• v.13 no.10
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• pp.697-702
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• 2003

FT-IR and thermograph were used to investigate the infrared radiation characteristics of $SiO_2$film made by the sol-gel method. FT-IR spectrum of the $SiO_2$film showed high infrared absorption by Si-O-Si vibration at 1220, 1080, 800 and cm$460^{-1}$ The infrared absorption and radiation wavelength ranges of the $SiO_2$film measured by the integration method coincided with the reflection method, and the infrared emissivity was 0.65, equally. Depending on the bonding of elements, the infrared emissivity was high in the wavelength range where the infrared absorption rate was high, that follows the Kirchhoff's law. The emissivity showed the highest value in the wavelength range between $8∼10\mu\textrm{m}$. $SiO_2$film was considered as an efficient materials for infrared radiator at temperature below 10$0^{\circ}C$. The heat radiation temperature was $117^{\circ}C$ for the aluminum plate, but $146^{\circ}C$ for the $SiO_2$film after 7 minutes heat absorption, consiquently, $29^{\circ}C$ higher than the former.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.239-245
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• 2000

Sintered $Al_2TiO_5$ has a very low thermal expansion and an infrared radiative selectively emitting large amounts of far infrared rays. However, it is week in mechanical strength. Spectral infrared emittance, thermal expansion coefficient, and mechanical strength of $Al_2TiO_5$-clay composites were studied to develop a material for far infrared radiators. The composites containing 10~50 mass% Jungsan clay had high emittance in the range of 2,000~500cm-1. The bending strength of the $Al_2TiO_5$-clay composites increased with increasing clay content. The $Al_2TiO_5$-clay composites with a clay content of 50mass% and heat-treated at $1,200^{\circ}C$ had a large strength for infrared radiators ; 86MPa. The average linear thermal expansion coefficient from $200{\sim}1,000^{\circ}C$ of the 50mass% jungsan clay containing compo sited heat-treated at $1,200^{\circ}C$ was lower than $3.87{\times}10-6/^{\circ}C$.