Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5459718 | Journal of Alloys and Compounds | 2017 | 19 Pages |
Abstract
The present study investigated microstructural characteristics of the oxide layer grown on AZ91 Mg alloy via plasma electrolytic oxidation (PEO) in order to reveal the formation of nanocrystalline and amorphous structures in the inner and outer parts of the oxide layer. For this purpose, PEO process was carried out under an alternating current condition at 50 mAcmâ2 in a phosphate-based electrolyte. The morphology of the oxide layer exhibited a porous structure with surface roughness value of â¼0.2 μm due to intense plasma discharges during PEO. The inner part of the oxide layer close to the substrate comprised mainly amorphous structure together with some crystalline grains of MgO. On the other hand, the outer part of the oxide layer was found to show nanocrystalline grains based on the analyses of the ring-like diffraction pattern. The nanocrystalline grains took place when the amorphous structure was subjected to the thermal energy from the plasma discharges between the electrolyte and oxide layer. The formation of different structures in the oxide layer was discussed in relation to discharge models in plasma electrolysis.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
M.P. Kamil, M. Kaseem, Y.H. Lee, Y.G. Ko,