Dependence of powder characteristics on die wall friction during ejection of compacts from die cavity

Taku Iwaoka, Yukiko Ozaki, Akira Fujiki

Research output: Contribution to journalArticle


The evaluation of ejection behavior is important to the final formability of green compact because both the ejection and the compression in the powder die compaction are affected by die wall friction. In other words, there is a hysteretic relationship between the lateral pressure and compacting pressure. In this paper, the effect of powder characteristics on the ejection die wall friction was studied using a powder model that considers the hardness and shape of the powder. The ejection behavior was classified on the basis of the powder's characteristics coefficient drawn from the model. Next, the influence of the particle size distribution, in addition to that of the hardness and shape of the powder, on the ejection behavior was shown.

Original languageEnglish
Pages (from-to)73-79
Number of pages7
JournalFuntai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy
Issue number2
Publication statusPublished - 2017 Feb 1



  • Die wall friction
  • Ejection
  • Hardness
  • Particle size distribution
  • Shape

ASJC Scopus subject areas

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

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