Cu/Li Ratio on the Microstructure Evolution and Corrosion Behaviors of Al-xCu-yLi-Mg Alloys

doi:10.1007/s40195-020-01023-1

Abstract

Abstract:

The microstructure evolution and the corrosion feature of Al-xCu-yLi-Mg alloys (x:y = 0.44, 1.65 and 4.2) were systematically investigated under the same artificial aging conditions. The relationships between types of precipitates and mechanical performance, as well as electrochemical behaviors, were discussed. Our results show that different types of precipitates can be obtained in alloys with different Cu/Li mass ratios, which significantly influences the mechanical performance of the alloys and substantial corrosion behaviors. Specifically, the analogous corrosion evolution in the aging Al-xCu-yLi-Mg alloys was first ascertained to be derived from the growth mechanism of the precipitates at the grain boundary (GB). Moreover, a small number of GB precipitates can be obtained in the aged alloy with the lowest Cu/Li mass ratio, thereby resulting in the largest intergranular corrosion resistance. A higher proportion of the GB T₁ phase in the continuous precipitates induces higher corrosion sensitivity in alloy with a high Cu/Li mass ratio.

Key words: Al-Cu-Li-Mg alloy, Cu/Li mass ratio, Microstructure evolution, Corrosion behaviors

Dan-Yang Liu, Jin-Feng Li, Yong-Cheng Lin, Peng-Cheng Ma, Yong-Lai Chen, Xu-Hu Zhang, Rui-Feng Zhang. Cu/Li Ratio on the Microstructure Evolution and Corrosion Behaviors of Al-xCu-yLi-Mg Alloys[J]. Acta Metallurgica Sinica (English Letters), 2020, 33(9): 1201-1216.

Figures/Tables 15

Table 1 Actual chemical composition of the prepared Al-xCu-yLi-Mg alloys (wt%)

Alloy	Cu/Li ratio	Cu	Li	Mg	Mn	Zr	Al
Alloy A	0.44	1.08	2.43	0.42	0.35	0.12	Bal.
Alloy B	1.65	2.78	1.68	0.43	0.32	0.12	Bal.
Alloy C	4.20	3.82	0.91	0.42	0.32	0.12	Bal.

Fig. 1 A schematic diagram of the aged specimens used in the tensile measurement

Fig. 2 Tensile properties of the Al-Cu-Li-Mg alloys with different Cu/Li ratios artificial aged at 175 °C: a yield strength; b tensile strength

Table 2 Statistical table of corrosion type and intergranular corrosion depth in Al-xCu-yLi-Mg alloys with different Cu/Li ratios aged at 175 °C

AT (h)	Cu/Li = 0.44 (low Cu/Li ratio)			AT (h)	Cu/Li = 1.65 (medium Cu/Li ratio)			AT (h)	Cu/Li = 4.20 (high Cu/Li ratio)
AT (h)	DCM	MID (μm)	AID (μm)	AT (h)	DCM	MID (μm)	AID (μm)	AT (h)	DCM	MID (μm)	AID (μm)
0.25	Pitting	-	-	0.25	LIGC	168.8	80.7	0.25	LIGC	261.3	166.3
0.5	LIGC	34.3	21.6	0.5	GIGC	206.3	140.3	0.5	LIGC	314.2	238.5
2	LIGC	53.2	44.5	2	GIGC	335.3	141.4	2	GIGC	358.1	276.1
4	LIGC	66.5	50.0	4	GIGC	356.4	215.7	4	GIGC	380.9	233.1
6	LIGC	110.8	70.5	6	GIGC	208.6	135.7	6	GIGC	301.5	223.9
8	LIGC	181.7	133.8	8	GIGC	284.2	203.1	8	LIGC	309.5	262.6
18	LIGC	106.1	72.3	12	LIGC	106.1	80.5	12	LIGC&P	< 10	< 5
32	LIGC	59.7	45.8	18	LIGC	90.2	52.9	26	Pitting	-	-
72	LIGC&P	52.7	453	26	Pitting	-	-	66	Pitting	-	-
100	LIGC&P	58.6	33.4	42	Pitting	-	-	80	LIGC&P	< 10	< 5
168	LIGC&P	80.3	64.5	54	Pitting	-	-	100	LIGC&P	< 10	< 5
198	Pitting	-	-	76	Pitting	-	-

Fig. 3 Typical morphology of corrosion in Al-Cu-Li-Mg alloys with different Cu/Li ratios: a Alloy A, low Cu/Li ratio, IA (2 h), LIGC; b Alloy B, medium Cu/Li ratio, IA (2 h), GIGC; c Alloy C, high Cu/Li ratio, IA (2 h), GIGC; d Alloy A, low Cu/Li ratio, UA (6 h), LIGC; e Alloy B, medium Cu/Li ratio, UA (6 h), GIGC; f Alloy C, high Cu/Li ratio, UA (6 h), GIGC; g Alloy A, low Cu/Li ratio, PA (24 h), LIGC; h Alloy B, medium Cu/Li ratio, PA (24 h), pitting; i Alloy C, high Cu/Li ratio, PA (24 h), pitting; j Alloy A, low Cu/Li ratio, OA (100 h), pitting; k Alloy B, medium Cu/Li ratio, OA (100 h), pitting; l Alloy C, high Cu/Li ratio, OA (100 h), pitting

Fig. 4 Corrosion morphology of the cross section of the Al-xCu-yLi-Mg alloys with different Cu/Li ratios aged at 175 °C: a LIGC; b GIGC; c Pitting; d LIGC&P

Fig. 5 IGC corrosion depth of Al-Cu-Li-Mg alloys with different Cu/Li ratios aged at 175 °C on different aging time points: a maximum IGC corrosion depth (MID); b average IGC corrosion depth (AID)

Fig. 6 TF curves and the OCP curves of Al-Cu-Li-Mg alloys with different Cu/Li ratios aged at 175 °C under different aging time points: a low Cu/Li ratio, Alloy A; b medium Cu/Li ratio, Alloy B; c high Cu/Li ratio, Alloy C; d OCP curves of these different Cu/Li ratios alloys

Fig. 7 TEM images of Al-Cu-Li-Mg alloys with different Cu/Li ratios aged at 175 °C on under-aging condition (6 h): a low Cu/Li ratio, Alloy A, DF, <100>Al; b low Cu/Li ratio, Alloy A, DF, <100>Al; c medium Cu/Li ratio, Alloy B, DF, <100>Al; d medium Cu/Li ratio, Alloy B, DF, <112>Al; e high Cu/Li ratio, Alloy C, BF, <100>Al; f high Cu/Li ratio, Alloy C, DF, <112>Al

Fig. 8 TEM images of Al-Cu-Li-Mg alloys with different Cu/Li ratios aged at 175 °C on peak aging condition (18 h): a low Cu/Li ratio, Alloy A, DF, <100>Al; b low Cu/Li ratio, Alloy A, DF, <100>Al; c medium Cu/Li ratio, Alloy B, DF, <100>Al; d medium Cu/Li ratio, Alloy B, DF, <112>Al; e high Cu/Li ratio, Alloy C, DF, <100>Al; f high Cu/Li ratio, Alloy C, DF, <112>Al

Fig. 9 TEM images of Al-Cu-Li-Mg alloys with different Cu/Li ratios aged at 175 °C on over-aging condition (66 h): a low Cu/Li ratio, Alloy A, DF, <100>Al; b low Cu/Li ratio, Alloy A, DF, <100>Al; c medium Cu/Li ratio, Alloy B, DF, <100>Al; d medium Cu/Li ratio, Alloy B, DF, <112>Al; e high Cu/Li ratio, Alloy C, DF, <100>Al; f high Cu/Li ratio, Alloy C, DF, <112>Al

Fig. 10 STEM image and the EDXS maps of Al-Cu-Li-Mg alloys with low Cu/Li ratio aged at 175 °C under peak aging condition (24 h)

Fig. 11 STEM image and he EDXS maps of Al-Cu-Li-Mg alloys with medium Cu/Li ratio aged at 175 °C under peak aging condition (24 h)

Fig. 12 STEM image and the EDXS maps of Al-Cu-Li-Mg alloys with high Cu/Li ratio aged at 175 °C under peak aging condition (24 h)

Table 3 Microstructure characteristics of the Al-xCu-yLi-Mg alloys with different Cu/Li ratios under peak aging condition

Precipitates type	Alloy C High Cu/Li ratio	Alloy B Medium Cu/Li ratio	Alloy A Low Cu/Li ratio
Major precipitates	T₁ phase, θ′ phase	δ′ phase, T₁ phase, θ′ phase	δ′ phase
Minor precipitates	S′ phase	S′ phase	T₁ phase, S′ phase
Precipitates at GB	A few T₁ phase	Some T₁ phase and coarse phase	A great many of T₁ phase and coarse phase

References 69

[1]	J.P. Immarigeon, R.T. Holt, A.K. Koul, L. Zhao, W. Wallace, J.C. Beddoes, Mater. Charact. 35, 41 (1995)
[2]	J. Ma, D.S. Yan, L.J. Rong, Y.Y. Li, Acta Metall. Sin. Engl. Lett. 28, 454 (2015)
[3]	V.I. Elagin, V.V. Zakharov, Met. Sci. Heat Treat. 55, 184 (2013)
[4]	Y.P. Tang, S. Hirosawa, S. Saikawa, K. Matsuda, S. Lee, Z. Horita, D. Terada, Adv. Eng. Mater. 33, 1900561 (2019)
[5]	K.D. Woo, S.W. Kim, J. Mater. Sci. 37, 411 (2002)
[6]	F. Zhang, J. Shen, X.D. Yan, J.L. Sun, N. Jiang, H. Zhou, Acta Metall. Sin. 50, 691 (2014)
[7]	S. Hirosawa, T. Sato, A. Kamio, H.M. Flower, Acta Mater. 48, 1797 (2000)
[8]	Z. Gao, J.H. Chen, S.Y. Duan, X.B. Yang, C.L. Wu, Acta Metall. Sin. Engl. Lett. 29, 94 (2016)
[9]	Y. Ma, H. Wu, X. Zhou, K. Li, Y. Liao, Z. Liang, L. Liu, Corros. Sci. (2019). https://doi.org/10.1016/j.corsci.2019.108110 URL PMID
[10]	M.X. Milagre, U. Donatus, C.S.C. Machado, J.V.S. Araujo, R.M.P. da Silva, B.V.G. de Viveiros, A. Astarita, I. Costa, Corros. Eng. Sci. Technol. 54, 402 (2019)
[11]	T.J. Konno, Met. Mater. Int. 10, 213 (2004)
[12]	J.C. Huang, A.J. Ardell, Acta Metall. 36, 2995 (1988) DOI URL
[13]	A.A. Alekseev, E.A. Lukina, Y.Y. Klochkova, Phys. Met. Metallog. 114, 481 (2013) DOI URL
[14]	J. Goebel, T. Ghidini, A.J. Graham, Mater. Sci. Eng. A 673, 16 (2016) DOI URL
[15]	R. Zhang, Y. Zhang, Y. Yan, S. Thomas, C.H.J. Daviesd, N. Birbilis, Corros. Sci. 126, 324 (2017) DOI URL
[16]	Y. Lin, Z.Q. Zheng, S.C. Li, X. Kong, Y. Han, Mater. Charact. 84, 88 (2013) DOI URL
[17]	X.L. Zhang, G.H. Wu, L. Zhang, C.C. Shi, J. Alloys Compd. 788, 367 (2019) DOI URL
[18]	S.G. Wang, Y. Huang, L. Zhao, Chin. J. Aeronaut. 31, 363 (2018) DOI URL
[19]	H. Ovri, E.A. Jagle, A. Stark, E.T. Lilleodden, Mater. Sci. Eng. A 637, 162 (2015)
[20]	S.F. Zhang, W.D. Zeng, W.H. Yang, C.L. Shi, H.J. Wang, Mater. Des. 63, 368 (2014) DOI URL
[21]	J. Entringer, M. Reimann, A. Norman, J.F. dos Santos, J. Mater. Res. Technol. 8, 2031 (2019) DOI URL
[22]	V. Araullo-Peters, B. Gault, F. de Geuser, A. Deschamps, J.M. Cairney , Acta Mater. 66, 199 (2014) DOI URL
[23]	B. Decreus, F. De Geuser, A. Deschamps, P. Donnadieu, C. Sigli, Solid Phase Transf. Inorg. Mater. Pts 172-174(267), 1-2 (2011)
[24]	Y.L. Ma, X.R. Zhou, X.M. Meng, W.J. Huang, Y. Liao, X.L. Chen, Y.N. Yi, X.X. Zhang, G.E. Thompson, Trans. Nonferrous Metal. Soc. 26, 1472 (2016) DOI URL
[25]	D.Y. Liu, F.J. Sang, J.F. Li, N. Birbilis, Z.X. Wang, Y.L. Ma, R.F. Zhang, Mater. Charact. (2019). https://doi.org/10.1016/j.matchar.2019.109981 URL PMID
[26]	J.V.D. Araujo, A.D.S. Bugarin, U. Donatus, C.D.C. Machado, F.M. Queiroz, M. Terada, A. Astarita, I. Costa, Corros. Eng. Sci. Technol. 54, 575 (2019) DOI URL
[27]	Y. Ma, X. Zhou, W. Huang, Y. Liao, X. Chen, X. Zhang, G.E. Thompson, Corros. Eng. Sci. Technol. 50, 420 (2015) DOI URL
[28]	W.J. Liang, Q.L. Pan, Y.B. He, Y.C. Li, Y.C. Zhou, C.G. Lu, Rare Met. 27, 146 (2008) DOI URL
[29]	J.F. Li, N. Birbilis, D.Y. Liu, Y.L. Chen, X.H. Zhang, C. Cai, Corros. Sci. 105, 44 (2016) DOI URL
[30]	V. Proton, J. Alexis, E. Andrieu, J. Delfosse, A. Deschamps, F. De Geuser, M.C. Lafont, C. Blanc, Corros. Sci. 80, 494 (2014) DOI URL
[31]	V.S. Sinyavskii, A.M. Semenov, Prot. Met. 38, 132 (2002) DOI URL
[32]	E. Ghanbari, A. Saatchi, X.W. Lei, D.D. Macdonald, Materials 12, 1786 (2019) DOI URL
[33]	A. Abd El-Aty, S.H. Zhang, Y. Xu, S. Ha, J. Mater. Res. Technol. 8, 1235 (2019) DOI URL
[34]	H.Y. Li, W.C. Yu, X.Y. Wang, R. Du, W. You, Metals 8, 1010 (2018) DOI URL
[35]	S.L. Yang, J. Shen, X.D. Yan, X.W. Li, F. Zhang, B.Q. Sun, Rare Met. Mater. Eng. 46, 28 (2017) DOI URL
[36]	B. Chen, C.H. Li, S.C. He, X.L. Li, C. Lu, J. Mater. Res. 29, 1344 (2014) DOI URL
[37]	A.A. Csontos, E.A. Starke, Metall. Mater. Trans. A 31, 1965 (2000) DOI URL
[38]	B. Decreus, A. Deschamps, F.D. Geuser, P. Donnadieu, C. Sigli, M. Weyland, Acta Mater. 61, 2207 (2013) DOI URL
[39]	D.Y. Liu, J.F. Li, Y.L. Ma, R.K. Gupta, N. Birbilis, R. Zhang, Corros. Sci. 145, 220 (2018) DOI URL
[40]	N. Ott, S.K. Kairy, Y.M. Yan, N. Birbilis, Metall. Mater. Trans. A 48, 51 (2017) DOI URL
[41]	J.F. Li, L. Xu, C. Cai, Y.L. Chen, X.H. Zhang, Z.Q. Zheng, Metall. Mater. Trans. A 45, 5736 (2014) DOI URL
[42]	K.L. Moore, J.M. Sykes, S.C. Hogg, P.S. Grant, Corros. Sci. 50, 3221 (2008) DOI URL
[43]	R. Khatami, A.A. Fattah, M.K. Keshavarz, J. Alloys Compd. 708, 316 (2017) DOI URL
[44]	N. Birbilis, R.G. Buchheit, J. Electrochem. Soc. 152, B140 (2005) DOI URL
[45]	R.G. Buchheit, J.P. Moran, G.E. Stoner, Corrosion 50, 120 (1994) DOI URL
[46]	M. Eddahbi, C.B. Thomson, F. Carreno, O.A. Ruano, Mater. Sci. Eng. A 284, 292 (2000) DOI URL
[47]	S.P. Lynch, A.R. Wilson, R.T. Byrnes, Mater. Sci. Eng. A 172, 79 (1993) DOI URL
[48]	J.J. de Damborenea, A. Conde, Br. Corros. J. 35, 48 (2000) DOI URL
[49]	Y.J. Deng, J.H. Bai, X.D. Wu, G.J. Huang, L.F. Cao, L. Huang, J. Alloys Compd. 723, 661 (2017) DOI URL
[50]	W.A. Cassada, G.J. Shiflet, E.A. Starke, Metall. Trans. A 22, 287 (1991) DOI URL
[51]	M. Murayama, K. Hono, Scr. Mater. 44, 701 (2001) DOI URL
[52]	L. Bourgeois, C. Dwyer, M. Weyland, J.F. Nie, B.C. Muddle, Acta Mater. 59, 704 (2011)
[53]	I. Hausler, R.D. Kamachali, W. Hetaba, B. Skrotzki, Materials (2019). https://doi.org/10.3390/ma12010030 URL PMID
[54]	X.Y. Wei, Z.Q. Zheng, L.J. She, Q.N. Chen, S.C. Li, Rare Met. Mater. Eng. 39, 1583 (2010)
[55]	X.X. Zhang, X. Zhou, T. Hashimoto, J. Lindsay, O. Cillca, C. Luo, Z. Sun, X. Zhang, Z. Tang, Corros. Sci. 116, 14 (2017) DOI URL
[56]	J.V.D. Araujo, U. Donatus, F.M. Queriroz, M. Terada, M.X. Milagre, M.C. de Alencar, I. Costa, Corros. Sci. 133, 132 (2018)
[57]	Y. Ma, X. Zhou, K. Li, S. Pawar, Y. Liao, Z. Jin, Z. Wang, H. Wu, Z. Liang, L. Liu, J. Electrochem. Soc. 166, C296 (2019) DOI URL
[58]	Y.L. Zou, X. Chen, B. Chen, J. Mater. Res. 33, 1011 (2018)
[59]	X.W. Lei, A. Saatchi, E. Ghanbari, R.Z. Dang, W.Z. Li, N. Wang, D.D. Macdonald, Materials (2019). https://doi.org/10.3390/ma12101600 URL PMID
[60]	C. Luo, X.X. Zhang, X.R. Zhou, Z.H. Sun, X.Y. Zhang, Z.H. Tang, F. Lu, G.E. Thompson, J. Mater. Eng. Perform. 25, 1811 (2016) DOI URL
[61]	X.X. Zhang, X.R. Zhou, T. Hashimoto, B. Liu, C. Luo, Z.H. Sun, Z.H. Tang, F. Lu, Y.L. Ma, Corros. Sci. 132, 1 (2018) DOI URL
[62]	T. Ramgopal, P.I. Gouma, G.S. Frankel, Corrosion 58, 687 (2002) DOI URL
[63]	J.F. Li, W.J. Chen, X.S. Zhao, W.D. Wen, Z.Q. Zheng, Trans. Nonferrous Metal. Soc. 16, 1171 (2006)
[64]	R.G. Buchheit, J.P. Moran, G.E. Stoner, Corrosion 46, 610 (1990)
[65]	C. Kumai, J. Kusinski, G. Thomas, T.M. Devine, Corrosion 45, 294 (1989) DOI URL
[66]	V. Singh, A.K. Mukhopadhyay, K.S. Prasad, Scr. Mater. 37, 1519 (1997) DOI URL
[67]	W. Huang, Y. Ma, X. Zhou, X. Meng, Y. Liao, L. Chai, Y. Yi, X. Zhang, Surf. Interface Anal. 48, 838 (2015) DOI URL
[68]	T. Dorin, A. Deschamps, F. De Geuser, F. Robaut, Mater. Sci. Eng. A 627, 51 (2015)
[69]	C. Luo, X. Zhou, G.E. Thompson, A.E. Hughes, Corros. Sci. 61, 35 (2012) DOI URL