• Journal of Conservation Science
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• v.9 no.1
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• pp.1-10
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• 2000

In 1993, many bronze artifacts were excavated from the Sanoesa Temple(思惱寺), Chongju, Chungbuk. Twelve items were selected and chemically analyzed with AA Spectrometry and ICP-Atomic Emission Spectrometry. They were also observed under the optical microscopy and SEM. According to the results from chemical analysis, production method and use, these artifacts were classified into four groups: casting, wrought and welding products, and bells. Cast products, probably used for ritual, were alloy of 70% Cu, 10% Sn and 20% Pb. They showed ${\alpha}+{\beta}$ phase as a typical microstructure of casting. The ${\delta}$ phase was rarely observed due to the small amount of Sn. These artifacts included more lead than other alloys. They showed segregation like island-shape on the lead part. Wrought products used for daily too1s. were alloy of 80% Cu and 20% Sn. Since they were consist of ${\alpha}$ phase and martensite ${\beta}$ phase, it could be presumed that they were heat-treated. The production method could be identified from twinned grains in ${\alpha}$ phase. Lead was not included in because it had a bad effect to alloy. The bells were alloyed with 85% Cu, 10% Sn, 5% Pb or 90% Cu and 10% Sn. They show the dendrite structure because they were cast and alloyed with many tin. Weldinged were alloyed with 83% Cu, 12% Sn and 5% Pb. lt showed the fine dendrite structure because of fast cooling in air.

• Journal of Conservation Science
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• v.36 no.3
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• pp.178-186
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• 2020

Verdigris is a traditional artificial pigment reported on old research papers and according to the methods mentioned in the literature, it is manufactured by the corrosion of copper or copper alloys using vinegar and by further scraping the generated rust. Since the Three Kingdoms Period, various household products with copper alloys, such as bronze and brass, have been used, and pigment analysis of these cultural heritage items has revealed the presence of tin, zinc, lead, and copper in green pigments. Based on these data, five types of verdigris were prepared from copper and copper alloys, and analyzed. the analysis results revealed a bluish green pigmentation, and the chromaticity, particle shape, and oil absorption quantity of each verdigris differed based on the type of copper alloy used in its preparation. The main components of verdigris are Cu, Sn, Zn and Pb, and their proportions depended on the type of copper alloy used during manufacturing. However, the main constituent mineral of the pigments is the same as 'hoganite[Cu(CH₃COO)₂·H₂O]', regardless of the copper alloy used. The result of accelerated weathering test for stability evaluation revealed that verdigris was discolored rapidly, thereby indicating that its stability was low, in particular, the pigments comprising lead presented relatively lower stability.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.98-104
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• 2014

Photovoltaic (PV) cell is considered as one of the finest ways to utilize the solar power. A study of improving solar cell's efficiency is important because the lifetime of solar cell is determined by photovoltaic module technology. Therefore, oxidation (and/or corrosion) of solder materials will be one of the primary yield and long-term reliability risk factor. Recently, the development of lead-free solder alloy has been done actively about lead-free solder alloys of the thermodynamic and mechanical properties. However, the oxidation behavior have rarely been investigated In this study, the oxidations of 60 wt% Sn-40 wt% Pb, 62 wt% Sn-36 wt% Pb -2 wt% Ag, 50wt% Sn-48 wt% Bi-2 wt% Ag alloys for the interconnect ribbon after exposure in atmosphere at $100^{\circ}C$ for several times were investigated. The wettability of 62 wt% Sn-36 wt% Pb-2 wt% Ag and 50 wt% Sn-48 wt% Bi-2 wt% Ag solders was also studied to compare with that of 60 wt% Sn-40 wt% Pb alloy. The results howed that the zero cross time and the wetting time of 50 wt% Sn-48 wt% Bi-2 wt% Ag solder were better than other two samples. The surface of tested samples was analyzed by XPS. The XPS result showed that in all samples, SnO grew first and then the mixture of SnO and $SnO_2$ was detected. $SnO_2$ grew predominantly for the long time aging. Moreover XPS depth profile analysis has found surface enrichment of tin oxide.

• Conservation Science in Museum
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• v.13
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• pp.33-36
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• 2012

Analysis of Flat board-shaped Lacquer ware excavated from Daho-ri was conducted. The result of species identification is identifed as Pinus spp. As a result of microscopic observation, lacquer fragment is consist of 5 layers and its thickness is about 100 ㎛. Infrared spectroscopy of the lacquer ware revealed that they had a very similar absorption band as refined lacquer, confirming that they were painted with lacquer. Result of Analysis for Circular metal ornament is alloy smelted by tin and lead. It is called Pewter. While The species of wooden objects investigated until now is broad-leaved tree; the species of flat board-shaped lacquer ware is conifer.

• Journal of the Korean Chemical Society
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• v.23 no.1
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• pp.52-58
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• 1979

Metallic dialkyldithiophosphates are widely used in lubricating oils as antioxidant and antiwear agents. Zinc DDTP are used most frequently in lubricating oil. Zinc, lead, tin and cobalt DDTP were prepared with primary and secondary alkyl groups. The effects of oxidation, thermal stability, metal corrosion and antiwear of each metallic DDTP prepared were studied. Based on the results, cobalt DDTP has a significant effect of antiwear on chrome alloy steel comparing with the other metallic DDTP. Also cobalt DDTP has a characteristic property of thermal sensitivity in its color, which was shown by the color change from brown to blue over a certain temperature. Another phenomenon obtained was that all metallic DDTP initiates the effect of antioxidation at the time of reaching to a certain effective acid concentration in lubricating oil.

• Journal of Conservation Science
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• v.28 no.2
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• pp.175-184
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• 2012

A purpose of this research is to find out characteristic of bronze artifacts and gold ornaments excavated from Xiongnu tombs No. 2~4 at Duurlig Nars in Mongolia through scientific analysis of them. The Tombs are comparatively small. There were still lots of relics remaining although the tombs had been already robbed. Also the tombs are evaluated important since the origin of them show coexisting of chinese and northern style. First of all, an analysis result about bronze vessels found in this site, they have high lead(Pb) content and relatively low tin(Sn) content, as compared with the Bronze Han Mirror and End-fittings of Bronze Parasol Rib. Especially in case of bronze tray and bronze lamp from the no. 2 tomb and also bronze cauldron from the no. 4 tomb contain only 1wt% of tin which means binary alloy composition(Cu-Pb). Also, in the case of gold ornaments found in the no. 2 tomb, they have comparatively high purity. And the research suppose that the high possibility of that they were used soldering using alloy of Au-Cu or diffused bonding(using malachite and copper oxide) for joining gold grains of gold granulation ornament. Further scientific research and analysis in Mongolia and other countries will provide more clues to solve mystery of Xiongnu culture.

• Conservation Science in Museum
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• v.16
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• pp.56-81
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• 2015

Ring in the scroll painting is one of the mounting elements which are fixed string and tassel to hang, these differ widely in shape and produce a variety of metals. Most traditional shapes of ring have been lost, because of remount, there are used Japanese style rings in present.Therefore, this study examines to shape, production technique and analyze component traditional style rings of 19 traditional scroll paintings in National Museum of Korea for restoration of original style. Ring has been recorded official names; Wonhwan(Ring), Gukhwadong(Chrysanthemum shaped ornaments), Baemok(Ring-shaped nail) in Uigwe. Result of an optical microscope (Leica, M205A), Wonhwan has two type of production technique; one is cutting and bending a metal rod and other is cast. Baemok is made to forging process after metal rod or plate by casting alloy. Baemok decoration is metal plate cutting shape, and then decorates it with pattern by using kicking line engraving, chasing and so on. Component analysis result from portable X-ray fluorescence found various metals, such as, brass, iron silver-cooper. Brass based on copper and zinc used rings of 17 scroll painting. Baemok of Yun Sidal portrait is used iron and plated with a tin-lead alloy. Yi Seogu portrait is silver-cooper alloy in whole ring.

• Conservation Science in Museum
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• v.23
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• pp.1-16
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• 2020

In this paper, Gilt-bronze Standing Avaolkiteshvara (National Treasure No. 293, M355) excavated at Gyuam-ri in Buyeo was observed with a microscope to identify the production technique applied to it. It was also analyzed with XRF and hard X-ray to identify the composition and the surface treatment techniques and casting method applied. In this statue, Avalokiteshvara is standing upright on a lotus pedestal. The lotus designs on the pedestal and those on the shawl flowing down on both sides of the statue are characteristic of Buddhist statues from the seventh century or later. The use of supports to affix the outer and inner molds and traces of injected cast were observed in the interior of the pedestal. The blisters on the arms and pedestal created during the bronze casting indicate the use of lost-wax casting, which was popularly employed for the production of mid- or small-sized gilt-bronze Buddhist statues in ancient times. The composition analysis identified a copper-tin-lead ternary alloy in the interior of the statue that was conventional used in the sixth and seventh centuries. It is likely that this simple alloy was used to facilitate casting and produce clearer expressions of designs and ornaments on the statue. Mercury (Hg) was detected on the surface of the statue, indicating the use of amalgam-plating with gold (Au) dissolved in mercury. This plating method is a common surface treatment technique used for small gilt-bronze statutes in ancient Korea.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.208-227
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• 2013

Twenty-seven bronze bowls excavated from the Goryo burial complex at Deobu-gol were examined for their microstructure and chemical composition to characterize the bronze technology practiced by commoners at the time. Results showed that the objects examined can be classified into four groups: 1) objects forged out of Cu-near 22%Sn alloys and then quenched; 2) objects cast from Cu-below 10% Sn alloys containing lead; 3) objects cast from Cu-10%~20% Sn alloys containing lead and then quenched; 4) objects forged out of Cu-10~20% Sn alloys containing lead and then quenched. This study revealed that the fabrication technique as determined by alloy compositions plays an important role in bronze technology. The use of lead was clearly associated with the selection of quenching temperatures, the character of inclusions and the color characteristics of bronze surfaces. It was found that the objects containing lead were quenched at temperatures of $520^{\circ}{\sim}586^{\circ}C$ while those without lead were quenched at the range of $586^{\circ}{\sim}799^{\circ}C$. The presence of selenium in impurity inclusions was detected only in alloys containing lead, suggesting that the raw materials, Cu and Sn, used in making the lead-free alloys for the first group were carefully selected from those smelted using ores without lead contamination. Furthermore, the addition of lead was found to have significant effects on the color characteristics of the surface of bronze alloys when they are subjected to corrosion during interment. In leaded alloys, corrosion turns the surface light green or dark green while in unleaded alloys, corrosion turns the surface dark brown or black. It was found that in fabrication, the wall thickness of the bronze bowls varies depending on the application of quenching; most of the quenched objects have walls 1mm thick or below while those without quenching have walls 1mm thick or above. Fabrication techniques in bronze making usually reflect social environments of a community. It is likely that in the late Goryo period, experiencing lack of skilled bronze workers, the increased demand for bronze was met in two ways; by the use of chief lead instead of expensive tin and by the use of casting suitable for mass production. The above results show that the Goryo bronze workers tried to overcome such a resource-limited environment through technological innovations as apparent in the use of varying fabrication techniques for different alloys. Recently, numerous bronze objects are excavated and available for investigation. This study shows that with the use of proper analytical techniques they can serve as a valuable source of information required for the characterization of the associated technology as well as the social environment leading to the establishment of such technology.

• Journal of Conservation Science
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• v.35 no.5
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• pp.392-402
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• 2019

This study interpreted the characteristics of the site and provenance of raw material by performing material characteristics analysis of the slags and tuyeres excavated from the Sinpung site in Wanju, Jeollabuk-do. The major chemical compositions suggested that the slags and tuyeres were created when Cu-Sn-Pb was alloyed. Metal microscope and scanning electron microscopy-energy dispersive spectrometer analyses revealed that the slags and tuyeres were by-products formed in the alloying process. This alloy, created by adding galena to copper and tin ingots, was an intermediary material used in making the finished products. According to the lead isotope ratio analysis result, slags could be made using galena of the southern Zone III region of Korea. Based on the decomposition of mica group minerals and the formation of mullite detected through X-ray diffraction analysis, it is possible to conclude that the tuyeres operated at approximately 1,000℃ as, the mullite was detected on the outside of the tuyeres.