Title: Predicting the immersion corrosion behaviour in NaCl solution of atmospheric plasma sprayed alumina coatings on AZ31B magnesium alloy

Authors: D. Thirumalaikumarasamy; K. Shanmugam; V. Balasubramanian

Addresses: Department of Manufacturing Engineering, Annamalai University, Annamalainagar – 608 002, Chidambaram, Tamil Nadu, India ' Department of Manufacturing Engineering, Annamalai University, Annamalainagar – 608 002, Tamil Nadu, India ' Center for Materials Joining Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalainagar – 608 002, Tamil Nadu, India

Abstract: The corrosion deterioration process of uncoated and plasma sprayed alumina coated AZ31B magnesium alloy, was investigated using immersion technique. The aim of the present work is to compare the corrosion behaviour of uncoated substrate and alumina plasma spray coatings on AZ31B magnesium alloy in NaCl environment at different pH values, chloride ion concentration and immersion time. Empirical relationship was established to predict the effect of immersion test parameters on corrosion rate. The corrosion products were examined by XRD, SEM/EDAX and X-ray mapping techniques. The results of immersion test in NaCl solution showed that the alumina coating exhibited a much better corrosion resistance than that of the bare Mg alloy.

Keywords: magnesium alloys; atmospheric plasma spraying; immersion test; corrosion rate; alumina coatings; sodium chloride; corrosion resistance.

DOI: 10.1504/IJCMSSE.2015.071655

International Journal of Computational Materials Science and Surface Engineering, 2015 Vol.6 No.2, pp.130 - 159

Received: 06 Sep 2014
Accepted: 21 Apr 2015
Published online: 09 Sep 2015 *

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