Unveiling initial oxidation behavior of Mg-Y-Zn long-period stacking ordered (LPSO) phase. (November 2022)

• Record Type: Journal Article
• Authors: Xu, L.D.; Ding, S.J.; Cai, X.C.; Wu, Y.; Li, Z.J.; Wen, K.K.; Xin, S.W.; Sun, B.R.; Huang, M.X.; Shen, T.D.
• Is Part Of: Corrosion science. Volume 208(2022)
• Publication Date: 2022-11
• Subjects: Long-period stacking ordered (LPSO) phase -- Oxidation behavior -- Microscopic oxidation mechanism -- Oxidation-resistant Mg alloys -- Thermodynamics; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110624
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: The oxidation of long-period stacking ordered (LPSO) phase has received little attention. The present work reveals the inherent oxidation behavior of Mg-Y-Zn LPSO phase at initial stage through detailed microstructural analysis and thermodynamic calculations. At a relatively low temperature (350 o C), Y2 O3 is the only oxidation product at the alloy surface, which shows a preferential nucleation and lateral growth behavior. Meanwhile, an underlying Mg-rich layer incorporated with Y-rich particles appears as a decomposition product of the LPSO phase. At a high temperature (500 o C), the long-range Y transport is dynamically suppressed by the thick Mg-rich shielding layer, prompting the preferential formation of MgO rather than Y2 O3 at the growth front. The present study would contribute to the development of oxidation-resistant LPSO-containing Mg alloys. Graphical Abstract: ga1 Highlights: The initial oxidation behavior of Mg-Y-Zn LPSO phase is well elucidated. The Y2 O3 layer exhibits a preferential nucleation and lateral growth behavior at 350 °C. The long-range Y transport is dynamically suppressed by the thick Mg-rich shielding layer at 500 °C. Preferential formation of MgO rather than Y2 O3 occurs at 500 °C.