MOLDING METHOD OF POWDER OF METAL, CERAMICS OR THE LIKE

摘要

PURPOSE:To obtain a molding having high dimensional accuracy in a molding method by a wet bag type cold hydrostatic press method by packing a raw material into a bag-shaped material consisting of an elastic material which is expanded by the reduced pressure of the outside atmosphere so as to contact tightly with the inside of an air permeable mold. CONSTITUTION:An air permeable mold support 7 is provided to the base 5 of a vacuum vessel 1 constituted of an upper cap 3 provided with a gate 2, a cylindrical part 4 and a lifting base 5. The upper aperture 8 of the support 7 is positioned concentrically with the gate 2 and the top surface thereof is brought into tight contact with the cap 3. The aperture of a thin-walled bag 9 consisting of the rubber-like elastic material is fixed to the gate 2 and the assembly is inserted to the inside of the support 7. The inside thereof is evacuated through a branch pipe on the part 4. A negative pressure is then generated on the outside of the support 7 and the bag 9 expands and contacts tightly with the entire inside surface of the support 7, thus forming the mold. The raw material powder 13 is then packed into the mold and the inside of the mold is evacuated to a vacuum through the aperture of the bag 9. The mold is sealed and the perform contained in the bag 9 is taken out of the support 7 and is subjected to cold hydrostatic press.