Chelliah, Nagaraj M and Padaikathan, Pambannan and Kumar, Ram (2019) Evaluation of electrochemical impedance and biocorrosion characteristics of as-cast and T4 heat treated AZ91 Mg-alloys in Ringer's solution. In: Journal of Magnesium and Alloys, 7 (1). pp. 134-143.
|
PDF
Mag_All_7-1_134_2019.pdf - Published Version Download (3MB) | Preview |
Abstract
The present study aims at understanding the electrochemical impedance and biocorrosion characteristics of AZ91 Mg-alloy in Ringer's solution. As-cast AZ91 Mg-alloy was subjected to T4 heat treatment in a way to homogenize its microstructure by dissolving most of the beta-Mg17Al12 phase at the vicinity of grain boundaries. The electrochemical impedance and biocorrosion performances of these two different microstructures (as-cast and T4 heat treated AZ91 Mg-alloys) in Ringer solution were evaluated by electrochemical impendence spectroscopy, potentiodynamic polarization and weight loss method. EIS spectra showed that both microstructures exhibit similar dynamic response as a function of the immersion time; however, the value of impedance and maximum phase angle are about 50% higher in as-cast AZ91 Mg-alloy as compared to that of homogenized AZ91 Mg-alloy. Weight loss measurement indicated that corrosion resistance of as-cast AZ91 was significantly better than that of homogenized AZ91. Microstructural and XRD analysis revealed that as-cast AZ91 contains a passive film of MgCO3 and CaCO3 precipitates with near spherical morphologies, whereas homogenized AZ91 comprised mainly unstable Mg(OH)(2) film featured by irregular plate-like morphologies. (C) 2019 Published by Elsevier B.V. on behalf of Chongqing University.
| Item Type: | Journal Article |
|---|---|
| Publication: | Journal of Magnesium and Alloys |
| Publisher: | National Engg. Reaserch Center for Magnesium Alloys |
| Additional Information: | Copyright of this article belongs to National Engineering Research Center for Magnesium Alloys |
| Keywords: | Mg-alloys;Ringers solution;Homogenization;Corrosion; Electrochemical impedance Spectroscopy(EIS);Weight loss |
| Department/Centre: | Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) |
| Date Deposited: | 21 Apr 2019 08:04 |
| Last Modified: | 21 Apr 2019 08:04 |
| URI: | http://eprints.iisc.ac.in/id/eprint/62290 |
Actions (login required)
 |
View Item |
