Influence of Grain Orientation on the Corrosion Behavior of Rolled AZ31 Magnesium Alloy

doi:10.1007/s40195-015-0337-2

Abstract

Abstract:

The effect of the grain orientation on corrosion behavior of rolled AZ31 magnesium alloy is investigated in this study. The test samples have a similar surface roughness to the Mg alloy in practical application. The immersion test and electrochemical impedance spectroscopy show that the TD-ND planes dominated by (101¯0), (112¯0) and (101¯1) oriented grains show a higher corrosion resistance compared with these of the RD-TD planes which consist mainly of (0001) oriented grains. Here, RD, ND and TD represent the rolling direction, the normal direction and the transverse direction of the alloy sheet, respectively. The surface morphologies of the alloys at various immersion stages are observed by scanning electron microscopy, and the surface topography of the alloy substitutes is also observed by laser scanning confocal microscopy. The TD-ND planes show a regular corrosion along the TD direction, but the RD-TD plane shows an irregular corrosion.

Key words: Magnesium alloys, Corrosion behavior, Electrochemical impedance spectroscopy, Crystallographic orientation

Yan-Chun Zhao, Guang-Sheng Huang, Guan-Gang Wang, Ting-Zhuang Han, Fu-Sheng Pan. Influence of Grain Orientation on the Corrosion Behavior of Rolled AZ31 Magnesium Alloy[J]. Acta Metallurgica Sinica (English Letters), 2015, 28(11): 1387-1393.

Figures/Tables 10

Fig. 1 Schematic illustration of the procedure to measure the volume of hydrogen evolved

Fig. 2 Texture components of the samples

Fig. 3 Surface topography of the samples

Fig. 4 Hydrogen evolution rate curves of the RD-TD and TD-ND plane in neutral 3.5% solution at room temperature

Fig. 5 Surface morphologies of the corrosion products a, b and the surface topographies of the magnesium alloy substitutes c, d at various immersion times

Fig. 6 EIS curves of the RD-TD and TD-ND plane after immersing for 0 h a, 3 h b, 5 h c, 9 h d and 24 h e in neutral 3.5% NaCl solution at room temperature

Fig. 7 Equivalent circuit of the EIS curves

Table 1 EIS fitting parameters and fitting error of the RD-TD plane

Immersion time	R _s (Ω cm^-2)	CPE_dl-T (uF cm^-2)	CPE_dl-P (n _dl)	R _t (Ω cm^-2)	C _f (uF cm^-2)	CPE_f-P (n _f)	R _f (Ω cm^-2)
0	9.746	27.75	0.9388	252.3	10,620	0.9998	11.02
3	5.816	62.58	0.9633	78.03	25,620	0.5564	15.98
5	4.767	56.87	0.9855	98.9	1410	0.7064	34.4
9	3.45	51.84	0.959	131	1720	0.787	25.05
24	5.59	47.32	0.9178	233.1	3509	0.9892	0.8052

Table 2 EIS fitting parameters and fitting error of the TD-ND plane

Immersion time	R _s (Ω cm^-2)	CPE_dl-T (uF cm^-2)	CPE_dl-P (n _dl)	R _t (Ω cm^-2)	C _f (uF cm^-2)	CPE_f-P (n _f)	R _f (Ω cm^-2)
0	9.924	40.83	0.967	165.5	5859	0.586	11.34
3	4.737	63.43	0.511	73.22	3059	0.857	14.566
5	4.336	66.23	0.9362	100.8	2707	1	17.385
9	6.125	66.18	0.9665	102.4	9978	0.481	19.19
24	4.794	56.44	0.9638	118.1	7132	0.885	27.08

Fig. 8 R t values for RD-TD and TD-ND plane after immersing for various times in neutral 3.5% NaCl solution at room temperature

References 19

[1]	K. Wen, K. Liu, Z.H. Wang, S.B. Li, W. Du, J. Magn. Alloys 3, 23 (2015)
[2]	Y.S. Zou, Y.F. Wu, Y.H. Yang, K. Cang, G.H. Song, Z.X. Li, K. Zhou, Appl. Surf. Sci. 258, 1624(2011)
[3]	H. Zhang, Y. Yan, J.F. Fan, W.L. Cheng, H.J. Roven, B.S. Xu, H.B. Dong, Mater. Sci. Eng. A 618, 540 (2014)
[4]	J.E. Gray, B. Luan, J. Alloys Compd. 336, 88(2002)
[5]	G.L. Song, A. Atrens, Adv. Eng. Mater. 5, 837(2003)
[6]	E. Ghali, W. Dietzel, K.U. Kainer, J. Mater. Eng. Perform. 13, 7(2004)
[7]	G.L. Song, A. Atrens, Adv. Eng. Mater. 1, 11(1999)
[8]	S.R. Agnew, M.H. Yoo, C.N. Tome, Acta Mater. 49, 4277(2001)
[9]	W.J. Kim, S.I. Hong, Y.S. Kim, S.H. Min, H.T. Jeong, J.D. Lee, Acta Mater. 51, 3293(2003)
[10]	R.L. Xin, B. Li, L. Li, Q. Liu, Mater. Des. 32, 4548(2011)
[11]	G.L. Song, R.J. Mishra, Z.Q. Xu, Electrochem. Commun. 12, 1099(2010)
[12]	D. Abayarathna, E.B. Hale, T.J. Corros. Sci. 32, 775(1991)
[13]	U. König, B. Davepon, Electrochim. Acta 47, 149 (2001)
[14]	Y.B. Ma, N. Li, D.Y. Li, M.L. Zhang, X.M. Huang, J. Power Sources 196, 2346 (2011)
[15]	L.L. Gao, C.H. Zhang, M.L. Zhang, X.M. Huang, N. Sheng, J. Alloys Compd. 468, 285(2009)
[16]	M. Anik, G. Celikten, Corros. Sci. 49, 1878(2007)
[17]	G. Galicia, N. Pébère, B. Tribollet, V. Vivier, Corros. Sci. 51, 1789(2009)
[18]	X.W. Guo, J.W. Chang, S.M. He, W.J. Ding, X.S. Wang, Electrochim. Acta 52, 2570 (2007)
[19]	N.G. Wang, R.C. Wang, C.Q. Peng, Y. Feng, B. Chen, Corros. Sci. 64, 17(2012)
	close