Liquid-Like, Self-Healing Aluminum Oxide during Deformation at Room Temperature

Yang Yang, Akihiro Kushima, Weizhong Han, Huolin Xin, Ju Li

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Effective protection from environmental degradation relies on the integrity of oxide as diffusion barriers. Ideally, the passivation layer can repair its own breaches quickly under deformation. While studies suggest that the native aluminum oxide may manifest such properties, it has yet to be experimentally proven because direct observations of the air-environmental deformation of aluminum oxide and its initial formation at room temperature are challenging. Here, we report in situ experiments to stretch pure aluminum nanotips under O2 gas environments in a transmission electron microscope (TEM). We discovered that aluminum oxide indeed deforms like liquid and can match the deformation of Al without any cracks/spallation at moderate strain rate. At higher strain rate, we exposed fresh metal surface, and visualized the self-healing process of aluminum oxide at atomic resolution. Unlike traditional thin-film growth or nanoglass consolidation processes, we observe seamless coalescence of new oxide islands without forming any glass-glass interface or surface grooves, indicating greatly accelerated glass kinetics at the surface compared to the bulk.

Original languageEnglish (US)
Pages (from-to)2492-2497
Number of pages6
JournalNano letters
Volume18
Issue number4
DOIs
StatePublished - Apr 11 2018

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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