Liquid-Like, Self-Healing Aluminum Oxide During Deformation At Room Temperature

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.

Publication Date

4-11-2018

Publication Title

Nano Letters

Volume

18

Issue

4

Number of Pages

2492-2497

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/acs.nanolett.8b00068

Socpus ID

85045217599 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85045217599

This document is currently not available here.

Share

COinS