• Title/Summary/Keyword: Metallurgical and thermodynamic base

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Composition Analysis and Thermodynamic Care for Replication of Ancient Metallic Type (고대 금속활자의 복제를 위한 성분분석과 열역학적 주의 점)

  • Kim, Ki-Ho
    • Journal of the Korean institute of surface engineering
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    • v.45 no.3
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    • pp.136-141
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    • 2012
  • 'Jikjisimcheyocheal (Jikji afterwards)' is known as a first book printed by the metal type in the world. The metal type used for printing this book has not been found yet. To help for replicating the original metal type, it is required to investigate the composition analysis of the copied metal type. In this study, the composition analysis and thermodynamic care for replicating of ancient metal type was performed on the basis of an analytical reports concerned with the ancient metal type which made after Jikji printing. Metal types were made by remelting and casting of the mother alloy which came from a cast of a mixed metals in accordance with the composition revealed in the literatures. Change of composition during remelting of mother alloy and casting of metal was detected by the EDS analysis. The reasons for variation in composition were discussed by metallurgical and thermodynamic point of view, and a mixing ratio of metals to get the original composition of ancient metal type is suggested. Some attention should be paid on mixing, melting and casting of metals to get an objected composition for copy of ancient metal type.

A Study on the Heat and Mass Balance of Smelting Reduction Process for Manganese Nodules (망간단괴 용융환원 제련공정의 물질 및 열수지 모델링)

  • Cho, Moon Kyung;Park, Kyung Ho;Min, Dong Joon
    • Korean Journal of Metals and Materials
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    • v.47 no.5
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    • pp.304-310
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    • 2009
  • Recently, manganese nodule has been focused on alternative resources because of its high grade of noble metallic elements such as Co, Ni, and Cu etc. From the viewpoint of an optimization the operating variables for energy efficiency of smelting reduction process, thermodynamic model for smelting reduction process of Manganese nodule was developed by using energy and material balance concept. This model provided that specific consumption of pure oxygen and coke was strongly depended on post combustion ratio (PCR) and heat transfer efficiency (HTE). The dressing and dehydrating process of low grade manganese can be proposed an essential process to minimize the specific energy consumption with decreasing slag volume. The effect of electricity coal base smelting reduction process was also discussed from the energy optimizing point of view.

Codeposition of Al and Cr by pack cementation (팩 세멘테이션에 의한 Al 및 Cr의 동시 코팅)

  • Sohn, Hee-Sik;Lee, Yoon-Je;Kim, Moon-Il
    • Journal of the Korean Society for Heat Treatment
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    • v.8 no.2
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    • pp.127-136
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    • 1995
  • The simultaneous addition of Al and Cr to the surface of Ni-and Fe-base alloy provides enhanced resistance to oxidation and corrosion in high temperatures. However, because of the large differences in thermodynamic stabilities of the volatile halides of Al and Cr, the codeposition of Al and Cr by halideactivated pack cementation is only possible for very specific, limited combinations of conditions. In this study, the experiments on the combinations of various metallic source powders and activators were conducted in order to obtain codeposition layers of Al and Cr on Ni with adequate composition by pack cementation. When Cr-Al masteralloy was used as a source powder, it was not easy to control Al and Cr content sensitively in the coating layers. On the other hand, when pure Cr and Al powder was used, ${\beta}$-NiAl layer containing about 20wt % Cr was obtained.

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