Basic study of die wall friction in ejection by lateral pressure measurement with the dual partitioning die in compaction

Taku Iwaoka, Yukiko Ozaki, Akira Fujiki

Research output: Contribution to journalArticle

1 Citation (Scopus)


In powder compaction, the ejection characteristics of green compact held in the die affect friction between the green compact side and die wall. The ejection characteristics are important factors for final formability of green compact. Therefore, this research studied factors that affect ejection friction. For ejection friction factors, we sought to measure lateral pressure that acts on the die wall, from compacting until ejection. We found that an increase in ejection friction coefficient does not necessarily increase ejection pressure. This phenomena was caused by lubricant that the compact supplies to the wall. By defining concrete material coefficient for powder, ejection characteristics have been explained. We found that powders with simpler shapes and/or lower yield strengths have superior ejection characteristics.

Original languageEnglish
Pages (from-to)422-430
Number of pages9
JournalFuntai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy
Issue number8
Publication statusPublished - 2015 Aug 1



  • Die compaction
  • Die wall friction
  • Ejection
  • Lateral pressure

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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