Light, strong, and stable nanoporous aluminum with native oxide shell

Wei Yang; Zhao-Ping Luo; Wei-Kang Bao; Hui Xie; Ze-Sheng You; Hai-Jun Jin

doi:10.1126/sciadv.abb9471

Light, strong, and stable nanoporous aluminum with native oxide shell

Sci Adv. 2021 Jul 9;7(28):eabb9471. doi: 10.1126/sciadv.abb9471. Print 2021 Jul.

Authors

Wei Yang^{1

2}, Zhao-Ping Luo¹, Wei-Kang Bao³, Hui Xie¹, Ze-Sheng You³, Hai-Jun Jin⁴

Affiliations

¹ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, PR China.
² School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, PR China.
³ Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, PR China.
⁴ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, PR China. hjjin@imr.ac.cn.

Abstract

Aluminum (Al) metal is highly reactive but has excellent corrosion resistance because of the formation of a self-healing passive oxide layer on the surface. Here, we report that this native aluminum oxide shell can also stabilize and strengthen porous Al when the ligament (strut) size is decreased to the submicron or nanometer scale. The nanoporous Al with native oxide shell, which is a nanoporous Al-Al₂O₃ core-shell composite self-organized in a galvanic replacement reaction, is nonflammable under ambient conditions and stable against coarsening near melting temperatures. This material is stronger than conventional foams of similar density consisting of pure Al or Al-based composites, and also lighter and stronger than most nanoporous metals reported previously. Its light weight, high strength, and excellent stability warrant the explorations of functional and structural applications of this material, if more efficient and scalable synthesis processes are developed in the future.

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