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.

Issue Section:
Research Papers
Keywords:
AZ31B magnesium alloy, magnetron sputtering, aluminum coating, corrosion resistance

References

1.
Gray
,
J. E.
 and
Luan
,
B.
, “
Protective Coatings on Magnesium and Its Alloys—A Critical Review
,”
J. Alloys Compd.
 0925-8388, Vol.
336
,
2002
, pp.
88
–
113
. https://doi.org/10.1016/S0925-8388(01)01899-0
Google Scholar
Crossref
Search ADS
 
2.
Hollstein
,
F.
,
Wiedemann
,
R.
, and
Scholz
,
J.
, “
Characteristics of PVD-Coatings on AZ31hp Magnesium Alloys
,”
Surf. Coat. Technol.
 0257-8972, Vol.
162
,
2003
, pp.
261
–
268
. https://doi.org/10.1016/S0257-8972(02)00671-0
Google Scholar
Crossref
Search ADS
 
3.
Zhang
,
J.
,
Wang
,
Y.
,
Zeng
,
R. C.
, and
Huang
,
W. J.
, “
Effects of Post Heat Treatment on the Interfacial Characteristics of Aluminum Coated AZ91D Magnesium Alloy
,”
Mater. Sci. Forum
 0255-5476, Vols.
546–549
,
2007
, pp.
529
–
532
. https://doi.org/10.4028/www.scientific.net/MSF.546-549.529
4.
Zhang
,
J.
 and
Sun
,
Z. F.
, “
Research on Magnesium Alloy AZ91D Surface Coating by Metallizing Aluminim
,”
China Mech. Eng
, Vol.
13
,
2002
, pp.
2057
–
2059
(in Chinese).
5.
Zhang
,
J.
 and
Wang
,
Y.
, “
Effect of Heat Treatment on Microstructures and Properties of Zinc-Aluminum Coating on AZ91D Magnesium Alloy
,”
Key Eng. Mater.
 1013-9826, Vols.
373–374
,
2008
, pp.
55
–
58
. https://doi.org/10.4028/www.scientific.net/KEM.373-374.55
6.
Wu
,
S. K.
,
Yen
,
S. C.
, and
Chou
,
T. S.
, “
A Study of r.f.-Sputtered Al and Ni Thin Films on AZ91D Magnesium Alloy
,”
Surf. Coat. Technol.
 0257-8972, Vol.
200
,
2006
, pp.
2769
–
2774
. https://doi.org/10.1016/j.surfcoat.2004.10.121
Google Scholar
Crossref
Search ADS
 
7.
Wu
,
G.
, “
Fabrication of Al and Al/Ti Coatings on Magnesium Alloy by Sputtering
,”
Mater. Lett.
 0167-577X, Vol.
61
,
2007
, pp.
3815
–
3817
. https://doi.org/10.1016/j.matlet.2006.12.082
Google Scholar
Crossref
Search ADS
 
8.
Bohne
,
Y.
,
Manova
,
D.
,
Blawert
,
C.
,
Stormer
,
M.
,
Dietzel
,
W.
, and
Mandl
,
S.
, “
Influence of Ion Energy on Morphology and Corrosion Properties of Mg Alloys Formed by Energetic PVD Processes
,”
Nucl. Instrum. Methods Phys. Res. B
 0168-583X, Vol.
257
,
2007
, pp.
392
–
396
. https://doi.org/10.1016/j.nimb.2007.01.030
Google Scholar
Crossref
Search ADS
 
9.
Liu
,
Y.
,
Overzet
,
L. J.
, and
Goeckner
,
M. J.
, “
Chemical Vapor Deposition of Aluminum from Methylpyrrolidine Alane Complex
,”
Thin Solid Films
 0040-6090, Vol.
510
,
2006
, pp.
48
–
54
. https://doi.org/10.1016/j.tsf.2005.12.156
Google Scholar
Crossref
Search ADS
 
10.
Zhang
,
J.
,
Yan
,
C.
, and
Wang
,
F.
, “
Electrodeposition of Al-Mn Alloy on AZ31B Magnesium Alloy in Molten Salts
,”
Appl. Surf. Sci.
 0169-4332, Vol.
255
,
2009
, pp.
4926
–
4932
.
Google Scholar
Crossref
Search ADS
 
11.
Chang
,
J. K.
,
Chen
,
S. Y.
,
Tsai
,
W. T.
,
Deng
,
M. J.
, and
Sun
,
I. W.
, “
Electrodeposition of Aluminum on Magnesium Alloy in Aluminum Chloride (AlCl3)–1-Ethyl-3-Methylimidazolium Chloride (EMIC) Ionic Liquid and Its Corrosion Behavior
,”
Electrochem. Commun.
 1388-2481, Vol.
9
,
2007
, pp.
1602
–
1606
. https://doi.org/10.1016/j.elecom.2007.03.009
Google Scholar
Crossref
Search ADS
 
12.
Chen
,
C.
,
Wang
,
M.
,
Wang
,
D.
,
Jin
,
R.
, and
Liu
,
Y.
, “
Lser Cladding of Al+Ir OPowders on ZM5 Magnesium Base Alloy
,”
Rare Metals
, Vol.
26
,
2007
, pp.
420
–
425
. https://doi.org/10.1016/S1001-0521(07)60239-3
Google Scholar
Crossref
Search ADS
 
13.
Wu
,
G.
,
Wang
,
X.
,
Ding
,
K.
,
Zhou
,
Y.
, and
Zeng
,
X.
, “
Growth and Corrosion of Aluminum PVD-Coating on AZ31 Magnesium Alloy
,”
Mater. Charact.
 1044-5803, Vol.
62
,
2009
, pp.
4325
–
4327
.
14.
Zhang
,
J.
,
Yang
,
D.
, and
Ou
,
X.
, “
Microstructures and Properties of Aluminum Film and Its Effect on Corrosion Resistance of AZ31B Substrate
,”
Trans. Nonferrous Met. Soc. China
 1003-6326, Vol.
18
,
2008
, pp.
s312
–
s317
. https://doi.org/10.1016/S1003-6326(10)60223-3
Google Scholar
Crossref
Search ADS
 
15.
Wu
,
G.
,
Zeng
,
X.
, and
Yuan
,
G.
, “
Growth and Corrosion of Aluminum PVD-Coating on AZ31 Magnesium Alloy
,”
Mater. Lett.
 0167-577X, Vol.
62
,
2008
, pp.
4325
–
4327
. https://doi.org/10.1016/j.matlet.2008.07.014
Google Scholar
Crossref
Search ADS
 
This content is only available via PDF.
All rights reserved. This material may not be reproduced or copied, in whole or in part, in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of ASTM International.
You do not currently have access to this content.