| 摘要 |
PURPOSE:To permit easy removal of a mandrel and the reuse thereof in a method for packing a powder material into a capsule space delineated by an inside cylinder, outside cylinder, top cap and bottom cap by disposing the mandrel into the central space of the capsule. CONSTITUTION:High-speed steel powder 6 produced by a gas atomization method is packed into the mild steel capsule 1 consisting of, for example, the inside cylinder 2, the outside cylinder 3, the top cap 4 and the bottom cap 5. The air in the powder-packed capsule is vented through a deaerating pipe 7 to hermetically seal the capsule. After the stainless steel mandrel 8 is set in the central part of the capsule 1, the capsule is subjected to a hot hydrostatic pressurization treatment. The mandrel 8 which has the same diameter as the inside diameter of the capsule 1 or has the inside diameter in the shrinkage range in the treatment stage of the capsule 1 is used as said mandrel. The molding having a straight inside surface is obtd. by the above-mentioned method and in addition, the sticking of the mandrel 8 and the powder material does not arise and therefore, the mandrel 8 is easily removed without using a release material and is reusable.
|
