Improving the electrochemical stability of AZ31 Mg alloy in a 3.5wt.% NaCl solution via the surface functionalization of plasma electrolytic oxidation coating

Journal of Magnesium and Alloys

Tehseen Zehra¹  Ali Dafali²  Burak Dikici³  Mosab Kaseem³  Hae Woong Yang⁴  Young Gun Ko⁵ 

[1] Corresponding authors.;Department of Metallurgical and Materials Engineering, Ataturk University, Erzurum 25240, Turkey;Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea;Faculty of Sciences Oujda, Department of Chemistry, Mohamed the First University, Oujda, Morocco;Pohang Institute of Metal Industry Advancement, Pohang 37666, Republic of Korea;

关键词: Hybrid composite;    Coordination bond;    Albumin;    Fatty acid;    Porous layer;    Corrosion;   

DOI  :  

来源: DOAJ

【 摘 要 】

The unique interactions between hexadecanoic acid (HA) and albumin (ALB) molecules on the surface of the porous layer of AZ31 Mg alloy were exploited to fabricate a novel hybrid composite film with excellent electrochemical stability in a 3.5 wt.% NaCl solution. Herein, the inorganic layer (IL) obtained by plasma electrolytic oxidation of AZ31 Mg alloy in an alkaline-phosphate-WO3 electrolyte was soaked in an organic solution composed of ALB and HA for 10 and 24 h at 60 °C. Although albumin and HA may coexist on the same surface of IL, the higher reactivity of ALB molecules would prevent the formation of a thick layer of HA. The donor-acceptor complexes formed due to the unique interactions between ALB and/or HA and IL surface would reduce the area exposed to the corrosive species which in turn would efficiently protect the substrate from corrosion. The porous structure of the IL would provide preferable sites for the physical and chemical locking triggered by charge-transfer phenomena, leading to the inhomogeneous nucleation and crystal growth of a flowery flakes-like organic layer. DFT calculations were performed to reveal the primary bonding modes between the ALB, HA, and IL and to assess the mechanistic insights into the formation of such novel hybrid composites.

【 授权许可】

Unknown