Microsoft Word - 250203-0902-OK.docAZ91D n-butyl-n-methylpyrrodine trifluoromethylsulfonate (BMP-NTf2)
*1 2 2 2 3 4
Corrosion Characteristics of Mg Alloys in n- butyl-n-methylpyrrodine
trifluoromethylsulfonate (BMP-NTf2) Ionic Liquids
J. K. Chang*1, P. C. Lin2, C. J. Su2, I. W. Sun2, W. T. Tsai3, C. M. Tseng4
Received 10 August 2010; received in revised form 14 June 2011; accepted 21 June 2011
AZ91 n-butyl-n-methylpyrrodine trifluoromethylsulfonate (BMP- NTf2)

160,000 -cm2 500 -cm2

79 ~ 84 2011 6
Journal of Chinese Corrosion Engineering, Vol. 25, No. 2, pp. 79 ~ 84 (2011)

1
1 Institute of Materials Science and Engineering, National Central University 2
2 Department of Materials Science and Engineering, National Cheng Kung University 3
3 Department of Chemistry, National Cheng Kung University 4
4 Center for Condensed Matter Sciences, National Taiwan University * jkchang@ncu.edu.tw
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ionic liquids and traditional aqueous solutions (as a counterpart). The Mg samples after being immersed in the ionic liquid were analyzed using a scanning electron microscope and an X-ray energy dispersive spectrometer. The experimental results indicated that the corrosion resistance of Mg in the ionic liquid was much better than that in traditional aqueous solutions, and the measured polarization resistances in the two environments were 160,000 and 500 -cm2, respectively.
Keywords: Mg alloy; Ionic liquid; Corrosion behavior.
1. CO2
20% CO2




) n-butyl-n-methylpyrrodine trifluoromethylsulfonate ionic liquid (BMP-NTf2)


9 wt% 0.5 wt%
AZ91D
2000

2.2 n-butyl-n-
methylpyrrodine trifluoromethylsulfonate (BMP-NTf2) 3.5 wt% NaCl


ferrocene/ferrocenium couple (Fc/Fc+ = 50/50 mol%)

(Polarization behavior) (AC impedance spectroscopy)
1 mV/s
AZ91D n-butyl-n-methylpyrrodine trifluoromethylsulfonate (BMP-NTf2)
10 mHz 100,000 Hz 0.1 Hz
2.3 BMP-NTf2
(99.9%)
(scanning electron microscope, SEM)
(EDS)
SEM --
β(Mg17Al12) α
2×10-4 A/cm2
2(b) 3.5 wt% NaCl
1 AZ91D SEM
Figure 1 SEM micrograph of the AZ91D alloy.
1E-6 1E-5 1E-4 1E-3 1E-2
Current density (A/cm2)
Current density (A/cm2)
Po te
nt ia
l ( V
v s.
SC E)
(a) (b) 2 (a) BMP-NTf2(b) 3.5 wt% NaCl
Figure 2 Polarization curves of the Mg alloys recorded in (a) the BMP-NTf2 ionic liquid and (b) a 3.5 wt% NaCl aqueous solution.
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NaCl
( ZPlot )
160,000 -cm2 3.5 wt% NaCl 3(b) 500 -cm2BMP-NTf2

Z'
-100000
-80000
-60000
-40000
-20000
0
Z' '
Z'
-1000
-800
-600
-400
-200
'
(a) (b) 3 (a) BMP-NTf2(b) 3.5 wt% NaCl
Figure 3 Nyquist plots of the Mg alloys recorded in (a) the BMP-NTf2 ionic liquid and (b) a 3.5 wt% NaCl aqueous solution.
4 BMP-NTf2
SEM
Figure 4 SEM micrograph of the AZ91D sample after being immersed in the BMP-NTf2 ionic liquid for two weeks.
(-cm2) (-cm2)








500 -cm2 160,000 -cm2
BMP-NTf2
3.5 wt% NaCl
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2010 8 10
2011 6 14
2011 6 21
5 SEM
Figure 5 SEM micrograph of the AZ91D sample after being immersed in water for one week.
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