J. Mater. Sci. Technol. ›› 2017, Vol. 33 ›› Issue (11): 1353-1361.DOI: 10.1016/j.jmst.2017.01.009

• Orginal Article • Previous Articles     Next Articles

Energy Absorption and Deformation Mechanism of Lotus-type Porous Coppers in Perpendicular Direction

Li Weidongab*(), Xu Kaic, Li Honghaod, Jia Haolingb*(), Liu Xinhuaa, Xie Jianxina*()   

  1. a Key Laboratory of Advanced Materials Processing, University of Science and Technology Beijing, Beijing 100083, China
    b Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, United States
    c State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
    d Department of Environmental Technology and Sustainability, New York Institute of Technology, Old Westbury, NY 11568, United States
  • Received:2016-09-20 Revised:2016-10-30 Accepted:2016-11-25 Online:2017-11-20 Published:2018-01-25
  • Contact: Li Weidong,Jia Haoling,Xie Jianxin
  • About author:

    1 These two authors contributed equally to this paper.

Abstract:

As metallic foams used for energy absorption in the automotive and aerospace industries, recently invented lotus-type porous metals are viewed as potential energy absorbers. Yet, solid conclusion on their eligibility as energy absorbers is still in question, particularly when compression is in the direction perpendicular to the axial orientation of cylindrical pores. In this work, the energy absorption of lotus-type porous coppers in the perpendicular direction is investigated at strain rates from 0.001 s-1 to?~2400 s-1. The energy absorption capacity and the energy absorption efficiency are calculated to be 4-16 kJ/kg and 0.32-0.7, respectively, slightly inferior to metal foams and the same porous solid compressed in the parallel direction due to the shortened extent of the plateau stress region. The deformation mechanism is examined experimentally in conjunction with finite element modeling. Both suggest that gradual squeeze and collapse of pores are the mechanisms accommodating the energy absorption. The deformation is generally evenly distributed over pore ligaments and independent of strain rate.

Key words: Lotus-type porous structure, Energy absorption, Plateau stress region, Plastic collapse, Strain rate effect