Materials Science

A revealing view of oxides

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Science  06 Apr 2018:
Vol. 360, Issue 6384, pp. 45-46
DOI: 10.1126/science.360.6384.45-e

Oxide layers provide a protective barrier coating for underlying metals, although, if damaged, they can accelerate underlying degradation such as corrosion in pitted areas or intergranular cracking. However, oxide layers often do not flow the same way as the underlying metal when stressed. Yang et al. used electron microscopy in an oxygen environment to probe the deformation of aluminum, a tricky problem because of the speed at which alumina forms. As two welded tips were pulled apart, the alumina showed liquid-like flow behavior that could match the movement of the underlying aluminum. At high deformation rates, where fresh aluminum was exposed, the authors observed self-healing of the coating through the seamless coalescence of new oxide islands.

Nano Lett. 10.1021/acs.nanolett.8b00068 (2018).

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