Low Frequency Electromagnetic Casting of 2195 Aluminum-Lithium Alloy and Its Effects on Microstructure and Mechanical Properties

doi:10.1007/s40195-019-00992-2

Abstract

Abstract:

In this study, the low frequency electromagnetic casting (LFEC) technology was adopted to fabricate 2195 Al-Li alloy. The microstructure and solid solubility of as-cast 2195 alloys, as well as the second phase precipitation and tensile properties after aging, were investiagated and compared with the counterpart direct chill casting 2195 alloy. Our results indicate that LFEC can significantly improve the microstructure and metallurgical quality of as-cast alloy, and increase the number density of θ′ (Al₂Cu) and T₁ (Al₂CuLi) phases during aging treatment due to the enhanced solubilities of alloying elements. The tensile properties of 2195 aged alloy cast by LFEC were hence improved evidently.

Key words: LFEC (low frequency electromagnetic casting), 2195 Aluminum-lithium alloy, Casting defects, Microstructure, Tensile property

Fu-Yue Wang, Xiang-Jie Wang, Wei Sun, Fang Yu, Jian-Zhong Cui. Low Frequency Electromagnetic Casting of 2195 Aluminum-Lithium Alloy and Its Effects on Microstructure and Mechanical Properties[J]. Acta Metallurgica Sinica (English Letters), 2020, 33(3): 338-350.

Figures/Tables 19

Table 1 Nominal and analyzed compositions of a 2195 alloy (wt%)

Fig. 1 Schematic illustration of the low frequency electromagnetic casting

Fig. 2 Schematic illustration of samples for microstructure observation and tensile test

Fig. 3 Microstructures of 2195 as-cast alloys cast by the different electromagnetic conditions: a DCC; b LFEC with 50 A/10 Hz; c LFEC with 50 A/20 Hz; d LFEC with 100 A/10 Hz; e LFEC with 100 A/20 Hz; f LFEC with 150 A/10 Hz; g LFEC with 150 A/20 Hz

Fig. 4 Grain sizes of 2195 as-cast alloys by DCC and LFEC

Fig. 5 Schematic diagram to compare the solidification features of DCC and LFEC

Fig. 6 Scanning acoustic microscope images of 2195 ingots by DCC and LFEC with 10 Hz/150 A

Table 2 Casting defects measured in the SAM images of 2195 ingots

Fig. 7 Element distribution of 2195 as-cast alloy by DCC a SEM microstruture of as-cast alloys; b Al; c Cu; d O; e Mg; f Ag

Fig. 8 Element distribution of 2195 as-cast alloy by LFEC with 150 A/10 Hz a SEM microstruture of as-cast alloys; b Al; c Cu; d O; e Mg; f Ag

Table 3 EDS analysis of chemical compositions of as-cast alloys in Fig. 7(a) (mole fraction%)

Fig. 9 DSC test of 2195 as-cast alloys by DCC and LFEC

Fig. 10 XRD diffraction peaks of α(Al) of 2195 as-cast alloys cast by DCC and LFEC: a (111) crystal face; b (200) crystal face; c (220) crystal face; d (311) crystal face

Table 4 Lattice parameters of α(Al) of 2195 as-cast alloy cast by DCC and LFEC

Fig. 11 Effects of current intensity on lattice parameters of α(Al) of 2195 as-cast alloy

Fig. 12 Micrographs of 2195 as-aged alloys: a DCC, b LFEC with 10 Hz/150A

Fig. 13 TEM images of the alloy after T6 treatment: a, b dark field image from <001 > α, θ′ phase; c, d bright field image from <112> α, T1 phase; a, c DCC; b, d LFEC with 150 A/10 Hz

Fig. 14 Area density of strengthening precipitates in 2195 alloy after T6 treatment: aθ′; bT1

Fig. 15 Tensile properties of 2195 aged alloy cast by DCC and LFEC

References

[1]	J.C. Williams, E.A. Starke, Acta Mater. 51, 5775(2003)
[2]	E.J. Lavernia, N.J. Grant, J. Mater. Sci. 22, 1521(1987)
[3]	T.S. Srivatsan, E.J. Lavernia, J. Mater. Sci. Lett. 9, 888(1990)
[4]	M. Guérin, J. Alexis, E. Andrieu, C. Blanc, G. Odemer, Mater. Des. 87, 681(2015)
[5]	N. Akhtar, W. Akhtar, S.J. Wu, Int. J. Cast Met. Res. 28, 1(2015)
[6]	S.J. Li, T. Jiang, J.Y. Wang, L. Chen, B. Wei, Mater. Sci. Eng. A 757, 14 (2019)
[7]	Q. Zhang, C.Y. Ban, J.Z. Cui, Q.X. Ba, G.M. Lu, Acta Phys. Sin. 52, 2642(2003)
[8]	S.H. Wang, S.J. Yang, C.F. Fang, J.Z. Wang, S.L. Dai, Trans. Nonferrous Met. Soc. China 19, 2083 (2009)
[9]	J.Z. Cui, Z.Q. Zhang, Q.C. Le, Trans. Nonferrous Met. Soc. China 20, 2046 (2010)
[10]	V. Charles, Metall. Trans. B 20, 623 (1989)
[11]	Y.B. Zuo, Z.H. Zhao, J.Z. Cui, Adv. Mater. Res. 402, 850(2011)
[12]	X.J. Wang, H.T. Zhang, Y.B. Zuo, Mater. Sci. Eng. A 497, 416 (2008)
[13]	D.D. Chen, H.T. Zhang, H. Jiang, J.Z. Cui, Mater. Sci. Eng. Technol. 42, 500(2011)
[14]	B.J. Zhang, J.Z. Cui, G.M. Lu, Mater. Sci. Eng. A 355, 325 (2003)
[15]	E.L. Huskins, B. Cao, K.T. Ramesh, Mater. Sci. Eng. A 527, 1292 (2010)
[16]	A. Deschamps, B. Decreus, F.D. Geuser, Acta Mater. 61, 4010(2013)
[17]	J. Dong, J.Z. Cui, F.X. Yu, Z.H. Zhao, Y.B. Zuo, J. Mater. Process. Technol. 171, 399(2006)
[18]	Y.B. Zuo, J.Z. Cui, H.T. Zhang, Mater. Sci. Eng. A 406, 286 (2005)
[19]	Y.B. Zuo, H. Nagaumi, J.Z. Cui, J. Mater. Process. Technol. 197, 109(2008)
[20]	E. Liott, A. Lui, R. Vincent, S. Kumar, Z. Guo, Acta Mater. 70, 228(2014)
[21]	H.B. Xu, Q.Y Han, T.M. Thomas, Mater. Sci. Eng. A 473, 96 (2008)
[22]	Q. Liu, R.H. Zhu, J.F. Li, Trans. Nonferrous Met. Soc. China 26, 607 (2016)
[23]	C.L. Wang, S.Z. Lin, Y. Niu, Appl. Phys. A 76, 157 (2003)
[24]	J. Su, F. Guo, H.S. Cai, L. Liu, J. Phys. Chem. Solids 131, 125 (2019)
[25]	L.Y. Jiang, W.J. Huang, Mater. Sci. Eng. A 752, 145 (2019)
[26]	J. Priede, G. Gerbeth, J. Cryst. Growth 285, 261 (2005)
[27]	Y. Wang, G. Zhao, X. Xu, X. Chen, W. Zhang, Mater. Sci. Eng. A 727, 78 (2018)
[28]	B. Jiang, F. Cao, H. Wang, D. Yi, Y. Jiang, Mater. Sci. Eng. A 740, 157 (2019)
[29]	M. Murayama, K. Hono, Scr. Mater. 44, 701(2001)
[30]	B.P. Huang, Z.Q. Zheng, Acta Mater. 46, 4381(1998)
[31]	W.A. Cassada, G.J. Shiflet, E.A. Starke, Metall. Trans. A 22, 287 (1991)
[32]	D. Tsivoulas, P.B. Prangnell, Acta Mater. 77, 1(2014)