Oxidation behavior of Ru–Al multilayer coatings
Research output: Journal Publications and Reviews (RGC: 21, 22, 62) › 21_Publication in refereed journal
|Journal / Publication||Applied Surface Science|
|Online published||14 Feb 2017|
|Publication status||Published - 1 Jun 2017|
|Link to Scopus||https://www.scopus.com/record/display.uri?eid=2-s2.0-85013638196&origin=recordpage|
Ru0.63Al0.37 coatings were deposited through a cyclical gradient concentration deposition at 400 °C with a substrate-holder rotation speed of 1 rpm by direct current magnetron cosputtering. Scanning electron microscopy revealed that the as-deposited coatings exhibited a multilayer structure along with the columnar structure. The oxidation behavior of the Ru0.63Al0.37 coatings was examined through X-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. Oxidation kinetics was measured using a thermogravimetric analyzer. Internal oxidation was observed for Ru0.63Al0.37 coatings annealed in a 1% O2–99% Ar atmosphere at 400–600 °C accompanied with activation energies of 72–84 kJ/mol. By contrast, external oxidation was observed after annealing at 700–800 °C, resulting in the formation of a continuous alumina scale consisting of crystalline δ-Al2O3 domains, which can be attributable to the outward diffusion of Al.
- Auger electron spectroscopy, Kinetics, Multilayer coatings, Nanostructure, Oxidation, X-ray photoelectron spectroscopy