Shin-etsu Chemical Co., Ltd.

Yoshihiro Umebayashi

Takahiro Hashimoto

Osamu Kohno

Eiji Uesaka

Ryuji Nakamura

Kenji Imamura

When a powder material () is molded by introducing the material into a cavity () between a lower punch () and a die (), compression molding the material between upper and lower punches (and) into a compact () of desired shape, and moving up the lower punch () to eject the compact (), a lubricant is applied to the interior surface of the die () by fitting a pad () around the lower punch () and impregnating the pad with the lubricant. Since the lubricant is applied on every molding operation, molding operation can be continuously carried out.

Powder molding apparatus and manufacture of rare earth sintered magnet using the apparatus

A rare earth sintered magnet is prepared from a corresponding alloy powder, using a mold comprising a die, an upper punch, and a lower punch which is divided into a plurality of punch segments which are independently movable within the die. The method comprises the steps of filling the mold cavity with the alloy powder when one or more selected punch segments are moved to a higher position than the remaining punch segments; moving the selected punch segments down to the position where the selected and remaining punch segments assume the normal shape of the lower punch during the compression step; compressing the alloy powder between the upper and lower punches under a magnetic field while the normal shape of the lower punch is maintained, for thereby molding a compact; and heat treating the compact.

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Echizen, Japan

Yoshihiro Umebayashi