ISSN: 1546-962X
CODEN: JAIOAD
Published Online: 21 April 2011
Page Count: 8

Effect of Aluminum Coating by Magnetron Sputtering on Corrosion Resistance of AZ31B Alloy

Zhang, Jin
Institute of Advanced Materials & Technology, Univ. of Science and Technology Beijing, Beijing,
Beijing Key Laboratory for Corrosion, Erosion and Surface Technology, Beijing,

Yang, Dong-Hua
Institute of Advanced Materials & Technology, Univ. of Science and Technology Beijing, Beijing,

(Received 8 July 2010; accepted 3 March 2011)

Abstract

In this study, aluminum coatings were prepared by dc magnetron sputtering on AZ31B magnesium alloy. The influence of sputtering parameters (include sputtering current, argon pressure, and deposition time) on corrosion behavior was investigated by potentiodynamic polarization tests in 3.5 % NaCl solution. The corrosion morphology was examined in detail by scanning electron microscopy and optical microscopy, respectively. It was found that the corrosion current density of magnesium alloy with aluminum coating was 2–3 orders of magnitude less than that of bare alloy. The corrosion potential with aluminum coating had been positive shift. The corrosion resistance of the coatings was strongly affected by its structure and residual stress, which depended on the process condition. Severe corrosion will occur after the aluminum coating is damaged due to the interaction of galvanic corrosion and other corrosion forms.

Keywords:
AZ31B magnesium alloy, magnetron sputtering, aluminum coating, corrosion resistance

Paper ID: JAI103228
DOI: 10.1520/JAI103228
ASTM International is a member of CrossRef.