Effect of heat treatment on corrosion and electrochemical behaviour of AZ91D magnesium alloy
نویسنده
چکیده
An AZ91D ingot in the as-cast condition was homogenized by solution treatment and then aged for various periods of time. The microstructures produced were studied in detail and the b phase volume fraction was measured quantitatively. The Corrosion resistance of all the different microstructures was studied in 3.5% NaCl solution through weight loss measurement in constant immersion conditions and potentiodynamic polarization experiments. The corroded surfaces were analysed using SEM and XRD. The volume fraction of the b phase was found to have a significant influence on the corrosion behaviour. The T4 condition improved the corrosion resistance of AZ91D alloy compared to the T6 heat treatment. The results support the idea of microgalvanic coupling between cathodic b phase and anodic a matrix.
منابع مشابه
Corrosion Resistance Enhancement of AZ91 Magnesium Alloy Using Ni-P Interlayer and Electrophoretic Deposited 3YSZ Coating
The zirconia stabilized by 3mol % Y2O3 (3YSZ) was applied onto the surface of the magnesium alloy AZ91D using electrophoretic deposition (EPD) from a non- aqueous solution. A Ni-P interlayer between the substrate and YSZ coating was also prepared by electroless plating. Finally, coatings were heat treated in control atmosphere at 400 °C. The preparation, microstructure and corrosion resistance ...
متن کاملCorrelation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys
* Corresponding author. Tel: 34 1 3944348; Fax: 34 1 3944357 E-mail: [email protected] ABSTRACT X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50oC. Commercially pure magnesium, used as the reference material, reveale...
متن کاملStudies on the in ̄uence of chloride ion and pH on the corrosion and electrochemical behaviour of AZ91D magnesium alloy
The in ̄uence of chloride ion concentration and pH on the corrosion and electrochemical behaviour of die-cast and ingot-cast AZ91D alloy have been studied with a focus on the stability of microconstituents in these environments. The experimental techniques used include immersion studies, potentiodynamic polarization, X-ray diraction and optical and scanning electron microscopy. The corrosion ra...
متن کاملInfluence of Sulfate-Reducing Bacteria on the Corrosion Residual Strength of an AZ91D Magnesium Alloy
In this paper, the corrosion residual strength of the AZ91D magnesium alloy in the presence of sulfate-reducing bacteria is studied. In the experiments, the chemical composition of corrosion film was analyzed by a scanning electron microscope with energy dispersive X-ray spectroscopy. In addition, a series of instruments, such as scanning electronic microscope, pH-meter and an AG-10TA materials...
متن کاملInfluence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy
The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical natur...
متن کامل