Characterization of Oxide Films Formed on Mg-Based WE43 Alloy Using AC/DC Anodization in Silicate Solutions
Open Access
- 1 January 2004
- journal article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 151 (1), B1-B10
- https://doi.org/10.1149/1.1629095
Abstract
The characteristics of the oxide film formed on a Mg-based WE43 alloy using ac/dc anodization techniques in an alkaline silicate solution have been investigated using scanning electron microscopy and Rutherford back-scattering spectroscopy, and the corrosion resistance of these films has been determined using the ac impedance technique. The oxide film was found to be composed of MgO, Mg(OH)2,Mg(OH)2, MgF2,MgF2, and SiO2,SiO2, and consisted of an inner barrier and an outer porous oxide film, both of which increased linearly in thickness with the applied anodization voltage. High applied voltages and current densities also led to the formation of large pores, having diameters greater than 6 μm, and the partial sealing of small pores in the outer layer. Allowing the current to decay for a period of time in the later stages of anodization led to an increase in the thickness of both the barrier and porous films and further sealing of the film pores. A correlation of the oxide corrosion resistance with the barrier film thickness is also demonstrated. © 2003 The Electrochemical Society. All rights reserved.Keywords
This publication has 12 references indexed in Scilit:
- Formation of Anodic Films on Magnesium Alloys in an Alkaline Phosphate ElectrolyteJournal of the Electrochemical Society, 2002
- Anodizing of Pure Magnesium in KOH‐Aluminate Solutions under SparkingJournal of the Electrochemical Society, 1999
- Constant Voltage Anodizing of Mg‐Al Alloys in KOH ‐ Al ( OH ) 3 SolutionsJournal of the Electrochemical Society, 1998
- Structure of Anodic Films Formed on MagnesiumJournal of the Electrochemical Society, 1996
- Morphology and Structure of Oxide Films Formed on Magnesium by Exposure to Air and WaterJournal of the Electrochemical Society, 1995
- Good days and bad days: People in finishing: Magnesium anodic coatersMetal Finishing, 1995
- Developments in Magnesium-Based Materials and ProcessesJournal of Engineering for Gas Turbines and Power, 1993
- Kinetics of growth of porous anodic Al2O3 films on A1 metalElectrochimica Acta, 1991
- Structure and mechanism of formation of oxide films on Fe single crystals by NaNO2Corrosion Science, 1967
- Studies of the Structure of Anodic Oxide Films on Aluminum, IJournal of the Electrochemical Society, 1959