Original Article
  • Cold Compaction Behavior of Nano and Micro Aluminum Powder under High Pressure

  • Dasom Kim*, Kwangjae Park*, Kyungju Kim**, Seungchan Cho***, Yusuke Hirayama****,
    Kenta Takagi****†, Hansang Kwon*,*****†

  • *Department of Materials System Engineering, Pukyong National University, Busan, Korea
    **The International Science Technology Research Center, Pukyong National University, Busan, Korea
    ***Department of Composites Research, Korea Institute of Materials Science, Changwon, Korea
    ****Magnetic Powder Metallurgy Research Center, National Institute of Advanced Industrial Science and Technology (AIST)
    *****†Department of R&D, Next Generation Materials Co., Ltd., Busan, Korea,
    Corresponding authors, Dr. Takagi Kenta (E-mail: k-takagi@aist.go.jp) and Prof. Hansang Kwon (E-mail: kwon13@pknu.ac.kr)

Abstract

In this study, micro-sized and nano-sized pure aluminum (Al) powders were compressed by unidirectional pressure at room temperature. Although neither type of Al bulk was heated, they had a high relative density and improved mechanical properties. The microstructural analysis showed a difference in the process of densification according to particle size, and the mechanical properties were measured by the Vickers hardness test and the nano indentation test. The Vickers hardness of micro Al and nano Al fabricated in this study was five to eight times that of ordinary Al. The grain refinement effect was considered to be one of the strengthening factors, and the Hall-Petch equation was introduced to analyze the improved hardness caused by grain size reduction. In addition, the effect of particle size and dispersion of aluminum oxide in the bulk were additionally considered. Based on these results, the present study facilitates the examination of the effect of particle size on the mechanical properties of compacted bulk fabricated by the powder metallurgy method and suggests the possible way to improve the mechanical properties of nano-crystalline powders.


Keywords: Aluminum, Powder metallurgy, Nanocrystalline material, Hall-Petch equation, Oxide dispersion strengthening

This Article

Correspondence to

  • Kenta Takagi****†, Hansang Kwon*,*****†

  • *Department of Materials System Engineering, Pukyong National University, Busan, Korea
    ****Magnetic Powder Metallurgy Research Center, National Institute of Advanced Industrial Science and Technology (AIST)
    *****†Department of R&D, Next Generation Materials Co., Ltd., Busan, Korea,

  • E-mail: k-takagi@aist.go.jp, kwon13@pknu.ac.kr