Structure, corrosion resistance and in vitro bioactivity of Ca and P containing TiO 2 coating fabricated on NiTi alloy by plasma electrolytic oxidation

In the present investigation, the plasma electrolytic oxidation (PEO) process was employed to form aluminum oxide coating layers to enhance corrosion resistance properties of high-strength aluminum alloys. The formed protective coating layers were examined by means of scanning electron microscopy (SEM) and characterized by several electrochemical techniques, including open circuit potential (OCP), linear potentiodynamic polarization (LP) and electrochemical impedance spectroscopy (EIS). The results were reported in comparison with the bare 6061-O aluminum alloy to determine the corrosion performance of the coated 6061-O alloy. The PEO-treated aluminum alloy showed substantially higher corrosion resistance in comparison with the untreated substrate material. A relationship was found between the coating formation stage, process parameters and the thickness of the oxide-formed layers, which has a measurable influence on enhancing corrosion resistance properties. This study demonstrates promising results of utilizing PEO process to enhance corrosion resistance properties of high-strength aluminum alloys and could be recommended as a method used in industrial applications.

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Tribological and corrosion resistance properties of graphite composite coating on AZ31 Mg alloy surface produced by plasma electrolytic oxidation

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2018.12.073 ◽

2019 ◽

Vol 359 ◽

pp. 197-205 ◽

Cited By ~ 10

Author(s):

Guo Peitao ◽

Tang Mingyang ◽

Zhang Chaoyang

Keyword(s):

Corrosion Resistance ◽

Composite Coating ◽

Plasma Electrolytic Oxidation ◽

Mg Alloy ◽

Alloy Surface ◽

Graphite Composite ◽

Az31 Mg Alloy ◽

Electrolytic Oxidation ◽

Plasma Electrolytic

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Effects of a Carbon Nanotube Additive on the Corrosion-Resistance and Heat-Dissipation Properties of Plasma Electrolytic Oxidation on AZ31 Magnesium Alloy

Materials ◽

10.3390/ma11122438 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2438 ◽

Cited By ~ 4

Author(s):

Myungwon Hwang ◽

Wonsub Chung

Keyword(s):

Corrosion Resistance ◽

Carbon Nanotube ◽

Plasma Electrolytic Oxidation ◽

Heat Dissipation ◽

X Ray ◽

Steady State Method ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Dissipation Property ◽

Peo Coatings

Plasma electrolytic oxidation (PEO) coating was obtained on AZ31 Mg alloy using a direct current in a sodium silicate-based electrolyte with and without a carbon nanotube (CNT) additive. The surface morphology and phase composition of the PEO coatings were investigated through field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The corrosion-resistance properties of the PEO coatings were evaluated using potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution. Furthermore, the heat-dissipation property was evaluated by a heat-flux measurement setup using a modified steady-state method and Fourier transform infrared spectroscopy (FT-IR). The results demonstrate that, by increasing the concentration of CNT additive in the electrolyte, the micropores and cracks of the PEO coatings are greatly decreased. In addition, the anticorrosion performance of the PEO coatings that incorporated CNT for the protection of the Mg substrate was improved. Finally, the coating’s heat-dissipation property was improved by the incorporation of CNT with high thermal conductivity and high thermal emissivity.

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