| 摘要 |
PURPOSE:To make closed molding by housing a compacted stock into dies, pushing a punch therein to pierce the stock and inserting a mandrel therein to expand the segments thereof thereby substantially filling the stick into the fine parts of the dies as well. CONSTITUTION:The stock obtd. by compacting fine powder is housed into a pair of the dies 28, 29. The punch is then pushed into the stock to pierce the stock and thereafter a mandrel 30 on a pedestal 19 is inserted by a cylinder. The segments of the mandrel 30 are thereafter expanded. The stock is heated to a high temp. and constant temp. by a graphite heating element 26 having a heating coil 21 in such a manner that superplastic working is executed. The stock is thus filled to all the corners of the dies by the hydrostatic pressure and the product having the good dimensional accuracy is obtd.
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