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Vol.52, No.3, 219 ~ 224, 2014
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| Title |
| Influence of Solidification Behavior of a Sublimable Vehicle in the Freeze-Drying Process of WO3/Camphene Slurry on Pore Structure |
| 오승탁 Sung Tag Oh , 이규태 Gyu Tae Lee , 이근재 Kun Jae Lee , 석명진 Myung Jin Suk |
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| Abstract |
| This paper describes the effect of the solidification behavior of camphene on the pore structure of porous W fabricated via a freeze-drying process. Camphene slurries with 10 and 15 vol% WO3 were prepared by milling at 50 ℃ with a small amount of dispersant. Porous W with unidirectionally aligned pore channels was prepared by freeze-drying of slurry and heat treatment in a hydrogen atmosphere. The sintered specimen with 10 vol% WO3 showed large pores with a size of about 100 μm which were aligned parallel to the growth direction of camphene. The internal wall of large pores had relatively small pores. In the slurry with 15 vol% WO3, large pores were not observed in the sintered body, and only small pores existed. The difference in the pore size in the two specimens is explained on the basis of the growth characteristics of the camphene dendrite depending on the amount of particles in the slurry. |
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| Key Words |
| porous materials, powder processing, solidification, scanning electron microscopy, W system |
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