Microstructure Characteristics, Texture Evolution and Mechanical Properties of Al-Mg-Si-Mn-xCu Alloys via Extrusion and Heat Treatment

doi:10.1007/s40195-024-01713-0

Abstract

Abstract:

In this work, the impact of extrusion and post-extrusion heat treatment (T6) on the microstructure and mechanical properties of the Al-1.2Mg-0.8Si-0.5Mn alloy with different Cu contents (0, 0.6, 1.3 and 2.0 wt%) was studied. Microstructure characterization showed that all extruded alloys exhibited elongated grain structure with an average grain size of~4.8 μm. The dominant texture components were deformation texture (A*, Copper and P texture), while the proportion of random texture initially increased and then decreased with increasing Cu content. After T6 treatment, the grain size of the four alloys increased significantly, but the growth trend decreased with increasing Cu content, and the textures transformed into recrystallized textures (Cube, A and Goss texture). Tensile testing revealed that the designed T6 alloys with 2.0% Cu content exhibited an excellent strength-ductility balance, i.e., a yield strength of 342.9 MPa, an ultimate tensile strength of 424.8 MPa and an elongation of 15.9%. The enhanced strength was mainly attributed to fine grain strengthening, solid solution strengthening and aging strengthening mechanisms. The superior ductility was due to the pinning effect of fine precipitates and high dislocation accommodation capacity caused by heat treatment.

Key words: Al-Mg-Si-Mn alloy, Cu addition, Microstructure texture, Mechanical, Properties

Zulai Li, Yingxing Zhang, Junlei Zhang, Xiang Chen, Suokun Chen, Lujian Cui, Shengjie Han. Microstructure Characteristics, Texture Evolution and Mechanical Properties of Al-Mg-Si-Mn-xCu Alloys via Extrusion and Heat Treatment[J]. Acta Metallurgica Sinica (English Letters), 2024, 37(9): 1501-1522.

Figures/Tables 20

Table 1 Chemical compositions of the four kinds of alloys in this study (wt%)

Samples state	Mg	Si	Mn	Cu	Fe	Al
1	1.23	0.85	0.46	-	0.08	Bal.
2	1.21	0.89	0.41	0.58	0.08	Bal.
3	1.26	0.86	0.42	1.33	0.11	Bal.
4	1.24	0.84	0.43	1.98	0.10	Bal.

Fig. 1 Schematic diagram of Al-Mg-Si-Mn-Cu alloy melting preparation and extrusion process

Fig. 2 As-cast metallographic diagram of four alloys: a 0Cu; b 0.6Cu; c 1.3Cu; d 2.0Cu; e grain size statistics for 1.3Cu and 2.0Cu; f SEM for 1.3Cu and EDS for selected portions of the area

Fig. 3 IPF maps (in ND): a ES-0Cu; b ES-0.6Cu; c ES-1.3Cu; d ES-2.0Cu; e SA-0Cu; f SA-0.6Cu; g SA-1.3Cu; h SA-2.0Cu

Fig. 4 Grain size distribution maps: a ES-0Cu; b ES-0.6Cu; c ES-1.3Cu; d ES-2.0Cu; e SA-0Cu; f SA-0.6Cu; g SA-1.3Cu; h SA-2.0Cu

Fig. 5 Diagram of PF: a ES-0Cu; b ES-0.6Cu; c ES-1.3Cu; d ES-2.0Cu; e SA-0Cu; f SA-0.6Cu; g SA-1.3Cu; h SA-2.0Cu

Fig. 6 SEM and EDS of four extruded alloys: a ES-0Cu; b ES-0.6Cu; c ES-1.3Cu; d ES-2.0Cu; e-h content of black and white precipitate phase elements; i and j EDS element scanning maps for ES-1.3Cu and ES-2.0Cu

Fig. 7 SEM and EDS of four T6-treated alloys: a SA-0Cu; b SA-0.6Cu; c SA-1.3Cu; d SA-2.0Cu; e-h content of black and white precipitate phase elements; i and j EDS element scanning maps for SA-1.3Cu and SA-2.0Cu

Fig. 8 XRD diagram of a extruded alloys and b T6-treated alloys

Fig. 9 Grain boundaries characteristics and recrystallization condition of four extruded alloys: a ES-0Cu; b ES-0.6Cu; c ES-1.3Cu; d ES-2.0Cu

Fig. 10 Grain boundaries characteristics and recrystallization condition of four T6-treated alloys: a SA-0Cu; b SA-0.6Cu; c SA-1.3Cu; d SA-2.0Cu

Fig. 11 Hardness diagrams of the extruded and T6-treated alloys: a ES-0Cu; b ES-0.6Cu; c ES-1.3Cu; d ES-2.0Cu; e SA-0Cu; f SA-0.6Cu; g SA-1.3Cu; h SA-2.0Cu

Fig. 12 Tensile engineering stress-strain curves of extruded samples: a tensile curves of the four extruded alloys; b tensile curve of the four T6-treated alloys; c YS and elongation combinations of 6xxx alloys; d UTS and elongation combinations of 6xxx alloys

Table 2 Mechanical properties of the four Al-Mg-Si-Mn alloys with different Cu contents at ES and SA states

Alloys	YS (MPa)		UTS (MPa)		El (%)
Alloys	ES	SA	ES	SA	ES	SA
0Cu	103.9±1.5	275.9±1.9	158.9±3.1	308.9±2.5	16.3±0.9	12.0±1.6
0.6Cu	130.5±2.6	291.5±1.5	204.5±2.8	360.6±3.9	21.5±0.8	18.6±0.9
1.3Cu	133.9±1.9	312.2±2.8	247.8±3.5	381.6±4.9	20.5±1.5	17.2±2.3
2.0Cu	200.2±1.1	342.9±3.2	301.5±2.4	424.8±3.9	17.6±2.3	15.9±1.6

Fig. 13 Tensile fracture diagram in different states: a ES-0Cu; b SA-0Cu; c ES-0.6Cu; d SA-0.6Cu; e ES-1.3Cu; f SA-1.3Cu; g ES-2.0Cu; h SA-2.0Cu

Fig. 14 Key to the position of the main ideal direction on φ2=45° section in ODF diagram

Fig. 15 Diagram of texture evolution: a ES-0Cu; b SA-0Cu; c ES-0.6Cu; d SA-0.6Cu; e ES-1.3Cu; f SA-1.3Cu; g ES-2.0Cu; h SA-2.0Cu

Fig. 16 Proportion diagram of different textures: a different texture proportions of four extruded alloys; b different texture proportions of four T6-treated alloys; c random texture of alloys in two different states

Fig. 17 Maps of KAM: a ES-0Cu; b SA-0Cu; c ES-0.6Cu; d SA-0.6Cu; e ES-1.3Cu; f SA-1.3Cu; g ES-2.0Cu; h SA-2.0Cu

Fig. 18 a, b, e and f TEM images of SA-1.3Cu. EDS analysis was conducted on the TEM images of the two points in b and the region A in f; c and d are high-resolution images of different shapes in the alloy

References 47

[1]	J. Hirsch, Trans. Nonferrous Met. Soc. China 24, 1995 (2014)
[2]	O.F. Hosseinabadi, M.R. Khedmati, Ocean Eng. 232, 109153 (2021)
[3]	M. Aamir, K. Giasin, M. Tolouei-Rad, A. Vafadar, J. Mater. Res. Technol. 9, 12484 (2020)
[4]	X.H. Fan, D. Tang, W.L. Fang, D.Y. Li, Y.H. Peng, Mater. Charact. 118, 468 (2016)
[5]	C. Zhang, C. Wang, Q. Zhang, G. Zhao, L. Chen, J. Mater. Process. Technol. 270, 323 (2019)
[6]	J.J. Sidor, R.H. Petrov, L.A.I. Kestens, Mater. Charact. 62, 228 (2011)
[7]	W. Chrominski, M. Lewandowska, Acta Mater. 103, 547 (2016)
[8]	J. Buha, R.N. Lumley, A.G. Crosky, K. Hono, Acta Mater. 55, 3015 (2007)
[9]	T. Abid, A. Boubertakh, S. Hamamda, J. Alloys Compd. 490, 166 (2010)
[10]	N.C.W. Kuijpers, F.J. Vermolen, C. Vuik, P.T.G. Koenis, K.E. Nilsen, S.V.D. Zwaag, Mater. Sci. Eng. A 394, 9 (2005)
[11]	X. Xu, Z. Yang, Y. Ye, G. Wang, X. He, Mater. Charact. 119, 114 (2016)
[12]	L. Ding, Z. Jia, Z. Zhang, R.E. Sanders, Q. Liu, G. Yang, Mater. Sci. Eng. A 627, 119 (2015)
[13]	J. Rakhmonov, K. Liu, P. Rometsch, N. Parson, X.G. Chen, J. Alloys Compd. 861, 157937 (2021)
[14]	X.P. Ding, H. Cui, J.X. Zhang, H.X. Li, M.X. Guo, Z. Lin, L.Z. Zhuang, J.S. Zhang, Mater. Des. 65, 1229 (2015)
[15]	Y. Weng, L. Ding, Z. Zhang, Z. Jia, B. Wen, Y. Liu, S. Muraishi, Y. Li, Q. Liu, Acta Mater. 180, 301 (2019)
[16]	W. Ding, X. Zhao, T. Chen, H. Zhang, X. Liu, Y. Cheng, D. Lei, J. Alloys Compd. 830, 154685 (2020)
[17]	S.B. Wang, C.F. Pan, B. Wei, X. Zheng, Y.X. Lai, J.H. Chen, J. Mater. Sci. Technol. 110, 216 (2022) DOI
[18]	H. Jiang, Q. Zheng, Y. Song, Y. Li, S. Li, J. He, L. Zhang, J. Zhao, Mater. Charact. 185, 111750 (2022)
[19]	X. Wu, Z.P. Guan, Z.Z. Yang, X. Wang, F. Qiu, H.Y. Wang, Mater. Sci. Eng. A 869, 144782 (2023)
[20]	M.X. Guo, J. Zhu, Y. Zhang, G.J. Li, T. Lin, J.S. Zhang, L.Z. Zhuang, Mater. Charact. 132, 248 (2017)
[21]	W. Jiang, J. Zhu, G. Li, F. Guan, Y. Yu, Z. Fan, J. Mater. Sci. Technol. 88, 119 (2021)
[22]	X. Liu, Y.L. Ma, X. Wang, S.Y. Zhang, M.X. Zhang, H.Y. Wang, Mater. Sci. Eng. A 872, 144945 (2023)
[23]	Y.J. Shi, Q.L. Pan, M.J. Li, Z.M. Liu, Z.Q. Huang, Trans. Nonferrours Met. Soc. China 25, 3560 (2015)
[24]	T. Radetic, M. Popovic, M. Novakovic, V. Rajic, E. Romhanji, J. Min. Metall. B 59, 327 (2023)
[25]	M. Zhang, D. Wang, H. Nagaumi, R. Wang, X. Zhang, P. Zhou, F. Wu, B. Zhang, Mater. Sci. Eng. A 889, 145840 (2024)
[26]	M. Pourgharibshahi, G. Timelli, Mater. Today Commun. 36, 106803 (2023)
[27]	X. Chen, G. Zhao, G. Liu, L. Sun, L. Chen, C. Zhang, J. Mater. Process. Technol. 275, 116348 (2020)
[28]	K.P. Mingard, B. Roebuck, E.G. Bennett, M.G. Gee, H. Nordenstrom, G. Sweetman, P. Chan, Int. J. Refract. Met. Hard Mater. 27, 213 (2009)
[29]	J. Zhang, S. Han, Y. Sun, X. Chen, P. Chen, Z. Li, G. Huang, F. Pan, Mater. Sci. Eng. A 880, 145329 (2023)
[30]	Z. Zhang, J.H. Zhang, J.S. Xie, S.J. Liu, Y.Y. He, R. Wang, D.Q. Fang, W. Fu, Y.L. Jiao, R.Z. Wu, Mater. Sci. Eng. A 831, 142259 (2022)
[31]	Z. Zhu, M.J. Starink, Mater. Sci. Eng. A 488, 125 (2008)
[32]	Y. Wang, Y. Deng, Q. Dai, K. Jiang, J. Chen, X. Guo, Mater. Sci. Eng. A 803, 140477 (2021)
[33]	J. Zhang, Y. Huang, J. Xiang, G. Huang, X. Chen, H. Zhou, B. Jiang, A. Tang, F. Pan, Mater. Sci. Eng. A 800, 140320 (2021)
[34]	Y. Zhang, J. Jiang, Y. Wang, G. Xiao, Y. Liu, M. Huang, J. Alloys Compd. 893, 162311 (2022)
[35]	G. Fan, G. Wang, H. Choo, P. Liaw, Y. Park, B. Han, E. Lavernia, Scr. Mater. 52, 929 (2005)
[36]	L. Hua, X. Hu, X. Han, Mater. Des. 196, 109192 (2020)
[37]	W. Liu, J. Morris, Metall. Mater. Trans. A 35, 265 (2004)
[38]	H. Xu, L.D. Xu, S.J. Zhang, Q. Han, Scr. Mater. 54, 2191 (2006)
[39]	M. Jin, J. Li, G.J. Shao, Mater. Sci. Forum 546, 825 (2007)
[40]	K. Yoshida, T. Ishizaka, M. Kuroda, S. Ikawa, Acta Mater. 55, 4499 (2007)
[41]	N.Q. Chinh, D. Olasz, A.Q. Ahmed, G. Sáfrán, J. Lendvai, T.G. Langdon, Mater. Sci. Eng. A 862, 144419 (2023)
[42]	W.J.P.X. Wang, S. Esmaeili, D.J. Lloyd, J.D. Embury, Metall. Mater. 34, 2913 (2003)
[43]	R. Li, M. Wang, Z. Li, P. Cao, T. Yuan, H. Zhu, Acta Mater. 193, 83 (2020)
[44]	M. Zha, Y. Li, R.H. Mathiesen, R. Bjørge, H.J. Roven, Acta Mater. 84, 42 (2015)
[45]	S. Esmaeili, D.J. Lloyd, W.J. Poole, Acta Mater. 51, 2243 (2003)
[46]	O.R. Myhr, Ø. Grong, S.J. Andersen, Acta Mater. 49, 65 (2001)
[47]	M.W. Zandbergen, A. Cerezo, G.D.W. Smith, Acta Mater. 101, 149 (2015)