Microstructure Evolution and Recrystallization Behavior During Hot Deformation of Spray Formed AlSiCuMg Alloy
WU Caihong1, FENG Di1(), ZANG Qianhao1, FAN Shichun1, ZHANG Hao2, LEE Yunsoo3
1.School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China 2.Jiangsu Haoran Spray Forming Alloy Co., Ltd., Zhenjiang 212009, China 3.Metallic Materials Division, Korea Institute of Materials Science, Changwon 51508, Korea
Cite this article:
WU Caihong, FENG Di, ZANG Qianhao, FAN Shichun, ZHANG Hao, LEE Yunsoo. Microstructure Evolution and Recrystallization Behavior During Hot Deformation of Spray Formed AlSiCuMg Alloy. Acta Metall Sin, 2022, 58(7): 932-942.
Wrought Al-Si alloy has partially replaced the traditional wear-resistant alloy for structural weight reduction owing to the excellent comprehensive properties, such as wear resistance, low coefficient of thermal expansion, and high specific strength. The deformation aluminum alloy based on Al-Si binary alloy is widely used in aerospace and automotive industries. The hot compression test, SEM, TEM, and EBSD technologies were used to investigate the microstructure evolution and dynamic recrystallization nucleation mechanism of spray formed Al25Si4Cu1Mg (mass fraction, %) alloy. The results show that the as-sprayed microstructure consists of equiaxed α-Al, coarse Si phase, AlSiCuMg phase, and Al2Cu phase with different scales. Under 623-723 K and 0.001-5 s-1, the fine Al2Cu phases gradually dissolve with the increase in deformation temperature. During high strain rate (5 s-1) compression, dislocation accumulation causes a high degree of stress concentration in front of the coarse and insoluble primary phases, resulting in the cracking of some brittle primary phases. Local cracks also appear at the interfaces between α-Al and primary phases. The α-Al phase undergoes complete dynamic recrystallization. The recrystallized grain size decreases with the increase and decrease in strain rate and deformation temperature, respectively. The residual dislocation and deformation substructure in the grain decrease with the increase in deformation temperature. The random texture demonstrates that the dynamic recrystallization mechanism of spray formed Al25Si4Cu1Mg alloy is “particle stimulated nucleation (PSN)”.
Fund: National Natural Science Foundation of China(51801082);Key Research and Development Program of Zhenjiang City(GY2021003);Key Research and Development Program of Zhenjiang City(GY2021020);Province Graduate Research and Innovation Projects in Jiangsu Province(202110289002Z);Postgraduate Research & Practice Innovation Program of Jiangsu(KYCX21_3453)
About author: FENG Di, associate professor, Tel: (0511)84401188, E-mail: difeng1984@just.edu.cn
Fig.1 Low (a) and high (b) magnified SEM images, the XRD spectrum (c), and the corresponding inverse pole figure (IPF) (d) of as-sprayed Al25Si4Cu1Mg (mass fraction, %) alloy
Zone
Composition / (atomic fraction, %)
Phase
Al
Si
Cu
Mg
1
61.83
-
38.17
-
Crystalline Al2Cu
2
17.29
32.87
12.31
37.53
AlSiCuMg
3
1.28
98.72
-
-
Si
4
97.03
-
2.97
-
Precipitated Al2Cu
Table 1 EDS analysis results for second phases of as-sprayed Al25Si4Cu1Mg alloy in Figs.1a and b
Fig.2 True stress-true strain curves of as-sprayed Al25Si4Cu1Mg alloy deformation at 623 K, 673 K, and 723 K under strain rates of 0.001 s-1 (a), 0.01 s-1 (b), 0.05 s-1 (c), 0.1 s-1 (d), 1 s-1 (e), and 5 s-1 (f)
Fig.3 Low (a, c, e, g, i) and high (b, d, f, h, j) magnified SEM images of as-sprayed and as-deformed microstructures under typical conditions of Al25Si4Cu1Mg alloy (Td—deformation temperature, —strain rate, DRX—dynamic recrystallization) (a, b) as-sprayed state (c, d) Td = 623 K, = 5 s-1 (e, f) Td = 723 K, = 5 s-1 (g, h) Td = 673 K, = 0.05 s-1 (i, j) Td = 723 K, = 0.001 s-1
Fig.4 TEM images of Al25Si4Cu1Mg alloy under different hot compression conditions (a, b) primary Si particles and deformed grains at Td = 673 K, = 0.05 s-1 (a) and Td = 623 K, = 5 s-1 (b) (c) interaction between dislocations and nano-Si particles at Td = 623 K and = 5 s-1
Fig.5 EBSD images of as-sprayed and deformed microstructures under different hot compressed conditions of Al25Si4Cu1Mg alloy (The grain boundaries colored by red indicate the misorientation in the range of 2°-15°. The grain boundaries colored by black indicate the misorientation > 15°) (a) as-sprayed (b) Td = 623 K, = 5 s-1 (c) Td = 723 K, = 5 s-1 (d) Td = 673 K, = 0.05 s-1 (e) Td = 723 K, = 0.001 s-1
Fig.6 {111} pole figures of as-sprayed and hot deformed Al25Si4Cu1Mg alloy microstructure (extrude direction-normal direction section) under different deformation conditions (a) as-sprayed state (b) Td = 623 K, = 5 s-1 (c) Td = 723 K, = 5 s-1 (d) Td = 673 K, = 0.05 s-1 (e) Td = 723 K, = 0.001 s-1
Fig.7 Schematics of hot deformation microstructure evolution of spray formed Al25Si4Cu1Mg alloy under different deformation conditions (Z—Zener-Hollomon parameter)
1
Sadeghi I, Wells M A, Esmaeili S. Effect of particle shape and size distribution on the dissolution behavior of Al2Cu particles during homogenization in aluminum casting alloy Al-Si-Cu-Mg [J]. J. Mater. Process. Technol., 2018, 251: 232
doi: 10.1016/j.jmatprotec.2017.08.042
2
Damavandi E, Nourouzi S, Rabiee S M, et al. Textural evaluation of Al-Si-Cu alloy processed by route BC-ECAP [J]. Met. Mater. Int., 2021, 27: 2756
doi: 10.1007/s12540-020-00953-w
3
Di Giovanni M T, Mørtsell E A, Saito T, et al. Influence of Cu addition on the heat treatment response of A356 [J]. Mater. Today Commun., 2019, 19: 342
doi: 10.1016/j.mtcomm.2019.02.013
4
Wang Y J, Liao H C, Wu Y N, et al. Effect of Si content on microstructure and mechanical properties of Al-Si-Mg alloys [J]. Mater. Des., 2014, 53: 634
doi: 10.1016/j.matdes.2013.07.067
5
Wu Y N, Liao H C, Zhou K X. Effect of minor addition of vanadium on mechanical properties and microstructures of as-extruded near eutectic Al-Si-Mg alloy [J]. Mater. Sci. Eng., 2014, A602: 41
6
Liao H C, Wu Y N, Ding K. Hardening response and precipitation behavior of Al-7%Si-0.3%Mg alloy in a pre-aging process [J]. Mater. Sci. Eng., 2013, A560: 811
7
Lin G Y, Tan X, Feng D, et al. Effects of conform continuous extrusion and heat treatment on the microstructure and mechanical properties of Al-13Si-7.5Cu-1Mg alloy [J]. Int. J. Min. Met. Mater., 2019, 8: 1013
8
Dang B, Zhang X, Chen Y Z, et al. Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy [J]. Sci. Rep., 2016, 6: 30874
doi: 10.1038/srep30874
pmid: 27502444
9
Hwang J W, Banerjee R, Doty H W, et al. The effect of Mg on the structure and properties of Type 319 aluminum casting alloys [J]. Acta Mater., 2009, 57: 1308
doi: 10.1016/j.actamat.2008.11.021
10
Zheng Q J, Ye Z F, Jiang H X, et al. Effect of micro-alloying element la on solidification microstructure and mechanical properties of hypoeutectic Al-Si alloys [J]. Acta Metall. Sin., 2021, 57: 103
Zhang J Y, Zuo L J, Feng J, et al. Effect of thermal exposure on microstructure and mechanical properties of Al-Si-Cu-Ni-Mg alloy produced by different casting technologies [J]. Trans. Nonferrous Met. Soc. China, 2020, 30: 1717
doi: 10.1016/S1003-6326(20)65333-X
12
Feng D, Han Z J, Li J C, et al. Evolution behavior of primary phase during pre-heat treatment before deformation for spray formed 7055 aluminum alloy [J]. Rare Met. Mater. Eng., 2020, 49: 4253
Jiang Y M, Zhao Y, Zhao Z X, et al. The strengthening mechanism of FSWed spray formed 7055 aluminum alloy under water mist cooling condition [J]. Mater. Charact., 2020, 162: 110185
doi: 10.1016/j.matchar.2020.110185
14
Wu Y N, Liao H C, Liu Y B, et al. Dynamic precipitation of Mg2Si induced by temperature and strain during hot extrusion and its impact on microstructure and mechanical properties of near eutectic Al-Si-Mg-V alloy [J]. Mater. Sci. Eng., 2014, A614: 162
15
Wu Y N, Liao H C, Yang J, et al. Effect of Si content on dynamic recrystallization of Al-Si-Mg alloys during hot extrusion [J]. J. Mater. Sci. Technol., 2014, 30: 1271
doi: 10.1016/j.jmst.2014.07.011
16
Ding K, Liao H C, Jin Q M, et al. Effect of hot extrusion on mechanical properties and microstructure of near eutectic Al-12.0%Si-0.2%Mg alloy [J]. Mater. Sci. Eng., 2010, A527: 6887
17
Hu Y S, Feng D, Zhou J D, et al. Constitutive equation and thermal processing map of spray formed AlSi25Cu4Mg wear resistant alloy [J]. Mater. Rep., 2020, 34: 10120
Zang Q H, Yu H S, Lee Y S, et al. Hot deformation behavior and microstructure evolution of annealed Al-7.9Zn-2.7Mg-2.0Cu (wt.%) alloy [J]. J. Alloys Compd., 2018, 763: 25
doi: 10.1016/j.jallcom.2018.05.307
19
Zang Q H, Yu H S, Lee Y S, et al. Effects of initial microstructure on hot deformation behavior of Al-7.9Zn-2.7Mg-2.0Cu (wt%) alloy [J]. Mater. Charact., 2019, 151: 404
doi: 10.1016/j.matchar.2019.03.019
20
Zang Q H, Feng D, Lee Y S, et al. Microstructure and mechanical properties of Al-7.9Zn-2.7Mg-2.0Cu (wt%) alloy strip fabricated by twin roll casting and hot rolling [J]. J. Alloys Compd., 2020, 847: 156481
doi: 10.1016/j.jallcom.2020.156481
21
Feng D, Zhang X M, Liu S D, et al. Effect of grain size on hot deformation behavior of a new high strength aluminum alloy [J]. Rare Met. Mater. Eng., 2016, 45: 2104
Feng D, Zhang X M, Liu S D, et al. Constitutive equation and hot deformation behavior of homogenized Al-7.68Zn-2.12Mg-1.98Cu-0.12Zr alloy during compression at elevated temperature [J]. Mater. Sci. Eng., 2014, A608: 63
23
Jazaeri H, Humphreys F J. The transition from discontinuous to continuous recrystallization in some aluminium alloys: I-The deformed state [J]. Acta Mater., 2004, 52: 3239
doi: 10.1016/j.actamat.2004.03.030
24
Feng D, Wang G Y, Chen H M, et al. Effect of grain size inhomogeneity of ingot on dynamic softening behavior and processing map of Al-8Zn-2Mg-2Cu alloy [J]. Met. Mater. Int., 2018, 24: 195
doi: 10.1007/s12540-017-7324-2
25
Zheng J H, Pruncu C, Zhang K, et al. Quantifying geometrically necessary dislocation density during hot deformation in AA6082 Al alloy [J]. Mater. Sci. Eng., 2021, A814: 141158
26
Huang K, Marthinsen K, Zhao Q L, et al. The double-edge effect of second-phase particles on the recrystallization behaviour and associated mechanical properties of metallic materials [J]. Prog. Mater. Sci., 2018, 92: 284
doi: 10.1016/j.pmatsci.2017.10.004
27
Wu Y N, Liao H C, Zhou K X, et al. Effect of texture evolution on mechanical properties of near eutectic Al-Si-Mg alloy with minor addition of Zr/V during hot extrusion [J]. Mater. Des., 2014, 57: 416
doi: 10.1016/j.matdes.2013.12.068
28
Wang X Y, Jiang J T, Li G A, et al. Particle-stimulated nucleation and recrystallization texture initiated by coarsened Al2CuLi phase in Al-Cu-Li alloy [J]. J. Mater. Res. Technol., 2021, 10: 643
doi: 10.1016/j.jmrt.2020.12.046
29
She H, Shu D, Dong A P, et al. Relationship of particle stimulated nucleation, recrystallization and mechanical properties responding to Fe and Si contents in hot-extruded 7055 aluminum alloys [J]. J. Mater. Sci. Technol., 2019, 35: 2570
doi: 10.1016/j.jmst.2019.07.014
