| 摘要 |
PROBLEM TO BE SOLVED: To provide a die where, even if compacting pressure is the high one, stress equal to or above yield stress is not applied to the corner parts of the inner wall of a die on which stress concentration is generated, and the generation of cracking and breaking in the corner parts is prevented. SOLUTION: Regarding the die where powder is packed into the cavity of the die, and the powder is compressed by the upper and lower punches, so as to form a green compact, the cavity passed through to the sliding direction of the punch in the die has a cross-sectional shape having corner parts, and, in the corner parts to which stress equal to or above the yield stress of the die is applied upon compacting among the corner parts, the die is split to the sliding direction of the punch from the tip of each corner part to the outer circumferential edge of the die, further, the split faces of the split dies are mutually pressure-welded, and also, at least one bent part is provided in the middle of the split line from the cavity side to the outer circumferential edge. COPYRIGHT: (C)2009,JPO&INPIT
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