Improving the corrosion properties of magnesium AZ31 alloy GTA weld metal using microarc oxidation process

M. Siva Prasad; M. Ashfaq; N. Kishore Babu; A. Sreekanth; K. Sivaprasad; V. Muthupandi

doi:10.1007/s12613-017-1438-x

Volume 24 Issue 5

May 2017

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Article Navigation > International Journal of Minerals, Metallurgy and Materials > 2017 > 24(5): 566-573

M. Siva Prasad, M. Ashfaq, N. Kishore Babu, A. Sreekanth, K. Sivaprasad, and V. Muthupandi, Improving the corrosion properties of magnesium AZ31 alloy GTA weld metal using microarc oxidation process, Int. J. Miner. Metall. Mater., 24(2017), No. 5, pp. 566-573. https://doi.org/10.1007/s12613-017-1438-x

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M. Siva Prasad, M. Ashfaq, N. Kishore Babu, A. Sreekanth, K. Sivaprasad, and V. Muthupandi, Improving the corrosion properties of magnesium AZ31 alloy GTA weld metal using microarc oxidation process, Int. J. Miner. Metall. Mater., 24(2017), No. 5, pp. 566-573. https://doi.org/10.1007/s12613-017-1438-x

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Research Article

Improving the corrosion properties of magnesium AZ31 alloy GTA weld metal using microarc oxidation process

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Corresponding author:
M. Siva Prasad E-mail: msiva048@gmail.com
Received: 20 November 2016; Revised: 17 December 2016; Accepted: 19 December 2016

Abstract

Abstract

In this work, the morphology, phase composition, and corrosion properties of microarc oxidized (MAO) gas tungsten arc (GTA) weldments of AZ31 alloy were investigated. Autogenous gas tungsten arc welds were made as full penetration bead-on-plate welding under the alternating-current mode. A uniform oxide layer was developed on the surface of the specimens with MAO treatment in silicate-based alkaline electrolytes for different oxidation times. The corrosion behavior of the samples was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy. The oxide film improved the corrosion resistance substantially compared to the uncoated specimens. The sample coated for 10 min exhibited better corrosion properties. The corrosion resistance of the coatings was concluded to strongly depend on the morphology, whereas the phase composition and thickness were concluded to only slightly affect the corrosion resistance.
- magnesium alloys;
- weldments;
- microarc oxidation;
- corrosion resistance

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