Powder compaction mold and method for manufacturing powder compact

A method for manufacturing a powder compact using a powder compaction mold,

• wherein the powder compaction mold comprises a die and upper and lower punches configured to fit into the die, the powder compaction mold being configured to compress a powder between the upper and lower punches to manufacture the powder compact,
• wherein, of the members forming the powder compaction mold, at least one of two members in sliding contact with each other has therein a vent passage through which gas is vented from a filling space for the powder surrounded by the die and the lower punch to an outside of the powder compaction mold,
• wherein the vent passage has a gas intake port that is open to a clearance section formed between the two members and connecting to the filling space,
• wherein, the clearance section is divided into, in a direction along the sliding contact between the two members, a first region on the filling space side, a second region including the intake port, and a third region other than these regions,
• the powder compaction mold has a wider clearance in the second region than in the first and third regions,
• wherein the clearance in the second region varies in the direction along the sliding contact between the two members,
• wherein the clearance in the second region is narrowest proximate the third region and becomes gradually wider toward the first region, and
• wherein the gas intake port is open on a surface defining the second region and the gas intake port is arranged at a position adjacent to the third region,
• the method comprising:
• a powder filling step of filling the filling space with the powder;
• a press compaction step of compressing the powder between the upper and lower punches to obtain the powder compact;
• and
• a removal step of moving the die and the lower punch relative to each other to remove the powder compact from the powder compaction mold,
• wherein gas is vented from the filling space through the vent passage in at least one of the powder filling step, the press compaction step, and the removal step.