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pISSN : 1598-706X / eISSN : 2288-8381


(논문)연구논문

한국주조공학회지 (14권1호 45-51)

Application of Bulk Talc to Molding Material

주형재료로서 덩어리 활석의 이용

Man-Jin Ha*, Zin-Hyoung Lee*, Sang-Soo Lee**,Hee-Joon Eun***

*KAIST, **National Museum, ***Korea Research Institute of Standards and Science

Abstract

The possibility of using bulk talc as molding material was reviewed and tested with the measurement of thermal properties and computer simulations. The measured thermal conductivity and heat diffusivity(kpc) of talc were $2.4W/m℃ and 6.6X10^6J^2/m^4^{\circ}C^2s, respectively. Thermal properties of talc could be ranked between those of sand mold and iron mold. Talc transforms into cristobalite and enstatite at 910℃, During the transformation volume and structure change, cracks appear on the surface and distortion occurs. Therefore talc can be used for molding material below 910℃ if carefully treated. Computer simulation was carried out to test whether talc insert could promote directional solidification in sand mold and iron mold. In sand mold, it was possible to achieve directional solidification of thin plate casting with the length to thickness ratio of 15, if both iron insert and talc insert were used. In iron mold, it was possible to achieve directional solidification only with talc insert.

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