• Journal of Conservation Science
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• v.32 no.4
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• pp.549-560
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• 2016

The purpose of this study is to identify the material characteristics of blackwares excavated from the Bonggok kiln site in Jinan-gun, Jeollabuk-do Province, South Korea, by scientific analyses and a reproduction experiment. Scientific analyses were conducted to determine the physical properties, chemical composition and for microscopic observation of blackwares. A reproduction experiment was also conducted by producing ceramic samples with black glaze, red ocher and limestone, and then cross sections of the samples were observed. The analysis results showed that all the excavated blackwares have similar properties such as chromaticity, specific gravity, absorption factor and porosity, but there is a difference depending on the crystallization of the ceramics. Thermal analysis showed that the exothermic peak was observed at about $1200^{\circ}C$, and crystal structure analysis indicated the presence of mullite. Hence, it can be concluded that the firing temperature of the excavated blackwares was around $1100-1200^{\circ}C$. Moreover, the glaze present on these blackwares has about 22% higher $Fe_2O_3$ content than those excavated from other places; however, the former has lower CaO content. For the reproduction experiment, samples were made using limestone as a flux and red ocher as a glaze. The results show that the cross section of the glaze layer of the reproduced sample have iron crystals with dendritic structures, similar to those present in the excavated black-wares. It is assumed that such iron crystals were formed during the process of melting and solidification of the iron oxide present in the blackwares.

• Journal of the Korean Ceramic Society
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• v.23 no.6
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• pp.15-24
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• 1986

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.28.1-28
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• 2002

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.430-437
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• 2004

This paper is intended as an investigation of study on the thermal and electrical characteristics of the carbon heating element. In this experimentation, the electric material used is the crystalline graphite a kind of natural graphite. The bentonite is used to solidify the heating element and the vacuum furnace is used for sintering it. It is noted that the natural drying time should be at least 58 hours. The plating of the electric pole with the electroless nickel showed the lowest contact resistance among others. The resistance shows linear variation with regard to length. For the insulation and resolution, the glaze coating is best with 80% of water content. The temperature rising characteristic of the heating element is better than sheath heater saving 43% of rising time. The correlation equation for temperature was obtained with the electric power.

• Journal of the Korean Ceramic Society
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• v.17 no.4
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• pp.213-216
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• 1980

A glass-ceramics material of composition %SiO_2$: 38.50, $Al_2O_3$: 26.00, $Na_2O$: 18.00, CaO: 6.00, MgO: 4.00, $TiO_2$: 7.50 was strengthened by coating a series of glazes$(SiO_2-B_2O_3-Al_2O_3-CaO-PbO-Na_2O-)$, which has lower thermal expansion coefficient than that of the glass-ceramics. The thermal expansion coefficient of the glazes ranges $80~90{\times}10^{-7}$cm/cm/$^{\circ}C$, whereas that of the glass-ceramics is $115{\times}10^{-7}$cm/cm/$^{\circ}C$. The glass-ceramics was identified to be composed of nepheline, carnegieite low form, and meta sodium silicate crystal by X-ray diffraction phase analysis. The glaze, having lower melting point and appropriate thermal expansion coefficient, was tried to be stable and good at secondary heat treatment.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.25-30
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• 1993

Materials (refractory, stone) of iron making furnace excavated from Kalcheon were investigated by the scanning electron microscopy(SEM) with an energy dispersive X-ray analysis (EDAX), X-ray fluorescence(XRF), and X-ray diffraction(XRD). Chemical composition of the refractory materials were $SiO_2(68.74\%),\;Al_2O_3(18.40\%),\;CaO(0.42\%),\;MgO(1.04\%)\;and\;K_2O(2.26\%)$ in weight ratio, which were the typical components presented in common clay. The results of chemical analysis for the stone and the glaze coated, alkali ion(K, Na, Ca) components of the glaze contained high concentration than that the stone. It was suggested that this change had a close relationship with the kinds of fuels used.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.8
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• pp.882-887
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• 2004

The new magnetic porcelain materials have been studied by mixing magnetic St-ferrite powders with traditional porcelain materials before forming process. For the maintenance of magnetic characteristics after glaze firing process, the Sr-ferrite grains with the size of 1∼2 ${\mu}{\textrm}{m}$ were agglomerated as the isotropic granules with the size of 0.5∼2 mm. The high characteristics of magnetic porcelain materials were achieved at the following conditions; isotropic Sr-ferrite granules of 30 wt%, granule size of 1.4∼2 mm, and glaze firing temperature of $1250^{\circ}C$ in air The magnetic porcelain materials indicated the high magnetic properties, such as the remanent flux density of 240 G, the intrinsic coercivity of 3910 Oe, and the surface flux density of 178 G. The extraction properties of the magnetic tea cups were high compared to that of the traditional tea cups.

• Water for future
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• v.29 no.2
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• pp.191-198
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• 1996

Attempts were made to determine a proper length scale representing characteristics of icing geometry. It was difficult to determine a single length scale especially for glaze icings because of their shape complexity. However, use of icing length, which is defined as the length of icing normal to the wind, as a characteristic length is suggested rather than the cylinder or cable diameter.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.144-152
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• 1963

A study was made of the effect of composition changes and particle size on appearance of raw bristol glazes fired at cones 5, 8, and 11. Alumina and silica, alkali and lime variations were made to get some of the more promising glazes determining maturing ranges, modulus of rupture, and other factors such as gloss, smoothness, opacity, eggshelling, crazing, pinholing and crawling for each glaze. Modulus of rupture was measured for the glazes fired at only cone 11.

• Conservation Science in Museum
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• v.7
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• pp.33-42
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• 2006

The Conservation Science Laboratory of the National Museum of Korea had drawn up the list of conservation treatment priority according to the artifact status in the collection and performed conservation treatment based on the priority list since 2006. This paper introduces the restoration process of the lost part of a black teacup(Sindo 1961) with newly developed restoration material. Part of the peeled off glaze was analyzed with LIBS and SEM-EDS analyser to find out the glaze ingredients that make the unique pattern of black teacup.