Influence of Solidification Behavior of a Sublimable Vehicle in the Freeze-Drying Process of WO3/Camphene Shiny on Pore Structure

초록

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 degrees C 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 mu m 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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