Microstructure and Mechanical Properties of Layered Heterostructured Mg-3Gd Alloy
LUO Xuan1,2, HAN Fang1,2, HUANG Tianlin1,2, WU Guilin3, HUANG Xiaoxu1,2()
1.International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China 2.Shenyang National Laboratory for Materials Science, Chongqing University, Chongqing 400044, China 3.Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
Cite this article:
LUO Xuan, HAN Fang, HUANG Tianlin, WU Guilin, HUANG Xiaoxu. Microstructure and Mechanical Properties of Layered Heterostructured Mg-3Gd Alloy. Acta Metall Sin, 2022, 58(11): 1489-1496.
As the lightest structural metallic materials, Mg alloys have immense development potential in the automotive, aerospace, medical, and electronic industries. However, the low strength and the poor ductility of Mg alloys limit their engineering applications. Recent investigations have shown that heterostructured Mg alloys exhibit significantly improved strength and ductility. This work applies accumulative roll-bonding and subsequent annealing to a Mg-3Gd alloy to produce layered heterostructures composed of alternating recovered and recrystallized layers of varying thicknesses. These heterostructures exhibit higher strength than homogeneous grain structures at a similar tensile ductility. They also show a continuous flow behavior desired for metal forming. A high density of the <c + a> dislocations is activated at the interfaces between the layers to accommodate the deformation incompatibility, which contributes to dislocation multiplications and accumulations and enhances work hardening rate and ductility.
Fig.1 TEM images (a, c) and sketches (b, d) showing a lamellar structure (a, b) and a twin block structure based on the experimental data reported in Ref.[27] (c, d) of the ARB-deformed Mg-3Gd alloy (RD—rolling direction, ND—normal direction, ARB—accumulative roll-bonding, LBs—lamellar boundaries, LAB—low-angle boundary, TB—twin boundary, SF—stacking fault. Inset in Fig.1d shows the corresponding electron diffraction pattern of a deformation twin (T1) and matrix)
Fig.2 SEM image (a), EBSD image (b), and TEM images (c, d) taken from the Mg-3Gd sample partially recrystallized at 290oC showing a layered heterostructure composed of alternating recovered and recrystallized layers of varying thicknesses
Fig.3 Tensile engineering stress-strain curves (a), tensile true stress-strain curves (b), work hardening rate-true strain curves (c), and work hardening rate-true stress curves (d) of the Mg-3Gd alloy with ARB-deformed structure, layered heterostructures (indicated by Hetero), and homogeneous recrystallized grain structures (indicated by Homo) (d—average grain size)
Fig.4 Uniform elongation versus yield strength of Mg-3Gd alloy with different microstructures and average grain sizes
Fig.5 Uniform elongation versus yield strength of AZ31 alloy plotted based on the experimental data reported in Ref.[24]
Fig.6 Dislocation structure analyses of the layered heterostructured Mg-3Gd sample after tensile deformation (a) bright field TEM image (Red line in Fig.6a shows the interface of recovered area and recrystallized area) (b) two-beam dark field TEM image with g = [0002] near the [] zone axis
1
Liu Q. Research progress on plastic deformation mechanism of Mg alloys [J]. Acta Metall. Sin., 2010, 46: 1458
doi: 10.3724/SP.J.1037.2010.00446
刘 庆. 镁合金塑性变形机理研究进展 [J]. 金属学报, 2010, 46: 1458
2
Hono K, Mendis C L, Sasaki T T, et al. Towards the development of heat-treatable high-strength wrought Mg alloys [J]. Scr. Mater., 2010, 63: 710
doi: 10.1016/j.scriptamat.2010.01.038
3
Agnew S R, Duygulu Ö. Plastic anisotropy and the role of non-basal slip in magnesium alloy AZ31B [J]. Int. J. Plast., 2005, 21: 1161
doi: 10.1016/j.ijplas.2004.05.018
4
Shi B D, Yang C, Peng Y, et al. Anisotropy of wrought magnesium alloys: A focused overview [J]. J. Magnes. Alloys, 2022, 10: 1476
doi: 10.1016/j.jma.2022.03.006
5
Nie J F. Precipitation and hardening in magnesium alloys [J]. Metall. Mater. Trans., 2012, 43A: 3891
6
Wang H Y, Xia N, Bu R Y, et al. Current research and future prospect on low-alloyed high-performance wrought magnesium alloys [J]. Acta Metall. Sin., 2021, 57: 1429
doi: 10.11900/0412.1961.2021.00347
Fan H D, Aubry S, Arsenlis A, et al. Grain size effects on dislocation and twinning mediated plasticity in magnesium [J]. Scr. Mater., 2016, 112: 50
doi: 10.1016/j.scriptamat.2015.09.008
8
Luo X. Effect of grain size on the mechanical behavior and deformation mechanisms of Mg-3Gd [D]. Chongqing: Chongqing University, 2019
Nie J F. Effects of precipitate shape and orientation on dispersion strengthening in magnesium alloys [J]. Scr. Mater., 2003, 48: 1009
doi: 10.1016/S1359-6462(02)00497-9
10
Yu H H, Li C Z, Xin Y C, et al. The mechanism for the high dependence of the Hall-Petch slope for twinning/slip on texture in Mg alloys [J]. Acta Mater., 2017, 128: 313
doi: 10.1016/j.actamat.2017.02.044
11
Huang X X. Size effects on the strength of metals [J]. Acta Metall. Sin., 2014, 50: 137
doi: 10.3724/SP.J.1037.2014.00016
Wu X L, Zhu Y T. Heterogeneous materials: A new class of materials with unprecedented mechanical properties [J]. Mater. Res. Lett., 2017, 5: 527
doi: 10.1080/21663831.2017.1343208
13
Zhu Y T, Ameyama K, Anderson P M, et al. Heterostructured materials: Superior properties from hetero-zone interaction [J]. Mater. Res. Lett., 2021, 9: 1
doi: 10.1080/21663831.2020.1796836
14
Ovid'ko I A, Valiev R Z, Zhu Y T. Review on superior strength and enhanced ductility of metallic nanomaterials [J]. Prog. Mater. Sci., 2018, 94: 462
doi: 10.1016/j.pmatsci.2018.02.002
15
Jin Z Z, Zha M, Wang S Q, et al. Alloying design and microstructural control strategies towards developing Mg alloys with enhanced ductility [J]. J. Magnes. Alloys, 2022, 10: 1191
doi: 10.1016/j.jma.2022.04.002
16
Li S J, Jin J F, Song Y H, et al. Multimodal microstructure of Mg-Gd-Y alloy through an integrated simulation of “process-structure-property” [J]. Acta Metall. Sin., 2022, 58: 114
Wu X L, Yang M X, Yuan F P, et al. Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility [J]. Proc. Natl. Acad. Sci. USA, 2015, 112: 14501
doi: 10.1073/pnas.1517193112
18
Zhang L, Chen Z, Wang Y H, et al. Fabricating interstitial-free steel with simultaneous high strength and good ductility with homogeneous layer and lamella structure [J]. Scr. Mater., 2017, 141: 111
doi: 10.1016/j.scriptamat.2017.06.044
19
Wang Y H, Kang J M, Peng Y, et al. Hall-Petch strengthening in Fe-34.5Mn-0.04C steel cold-rolled, partially recrystallized and fully recrystallized [J]. Scr. Mater., 2018, 155: 41
doi: 10.1016/j.scriptamat.2018.06.019
20
Luo X, Feng Z Q, Yu T B, et al. Transitions in mechanical behavior and in deformation mechanisms enhance the strength and ductility of Mg-3Gd [J]. Acta Mater., 2020, 183: 398
doi: 10.1016/j.actamat.2019.11.034
21
Xu C, Fan G H, Nakata T, et al. Deformation behavior of ultra-strong and ductile Mg-Gd-Y-Zn-Zr alloy with bimodal microstructure [J]. Metall. Mater. Trans., 2018, 49A: 1931
22
Go Y, Jo S M, Park S H, et al. Microstructure and mechanical properties of non-flammable Mg-8Al-0.3Zn-0.1Mn-0.3Ca-0.2Y alloy subjected to low-temperature, low-speed extrusion [J]. J. Alloys Compd., 2018, 739: 69
doi: 10.1016/j.jallcom.2017.12.229
23
Zhang H, Wang H Y, Wang J G, et al. The synergy effect of fine and coarse grains on enhanced ductility of bimodal-structured Mg alloys [J]. J. Alloys Compd., 2019, 780: 312
doi: 10.1016/j.jallcom.2018.11.229
24
Luo X, Huang T L, Wang Y H, et al. Strong and ductile AZ31 Mg alloy with a layered bimodal structure [J]. Sci. Rep., 2019, 9: 5428
doi: 10.1038/s41598-019-41987-4
pmid: 30932008
25
Zheng R X, Bhattacharjee T, Gao S, et al. Change of deformation mechanisms leading to high strength and large ductility in Mg-Zn-Zr-Ca Alloy with fully recrystallized ultrafine grained microstructures [J]. Sci. Rep., 2019, 9: 11702
doi: 10.1038/s41598-019-48271-5
pmid: 31406235
26
Zheng R X, Bhattacharjee T, Shibata A, et al. Simultaneously enhanced strength and ductility of Mg-Zn-Zr-Ca alloy with fully recrystallized ultrafine grained structures [J]. Scr. Mater., 2017, 131: 1
doi: 10.1016/j.scriptamat.2016.12.024
27
Luo X, Feng Z Q, Yu T B, et al. Microstructural evolution in Mg-3Gd during accumulative roll-bonding [J]. Mater. Sci. Eng., 2020, A772: 138763
28
Tsuji N, Ito Y, Saito Y, et al. Strength and ductility of ultrafine grained aluminum and iron produced by ARB and annealing [J]. Scr. Mater., 2002, 47: 893
doi: 10.1016/S1359-6462(02)00282-8
29
Huang X X, Hansen N, Tsuji N. Hardening by annealing and softening by deformation in nanostructured metals [J]. Science, 2006, 312: 249
pmid: 16614217
30
Kamikawa N, Huang X X, Tsuji N, et al. Strengthening mechanisms in nanostructured high-purity aluminium deformed to high strain and annealed [J]. Acta Mater., 2009, 57: 4198
doi: 10.1016/j.actamat.2009.05.017
31
Huang T L, Shuai L F, Wakeel A, et al. Strengthening mechanisms and Hall-Petch stress of ultrafine grained Al-0.3%Cu [J]. Acta Mater., 2018, 156: 369
doi: 10.1016/j.actamat.2018.07.006
32
Gao S, Chen M C, Joshi M, et al. Yielding behavior and its effect on uniform elongation in IF steel with various grain sizes [J]. J. Mater. Sci., 2014, 49: 6536
doi: 10.1007/s10853-014-8233-0
33
Tsuji N, Ogata S, Inui H, et al. Strategy for managing both high strength and large ductility in structural materials—Sequential nucleation of different deformation modes based on a concept of plaston [J]. Scr. Mater., 2020, 181: 35
doi: 10.1016/j.scriptamat.2020.02.001
34
Koike J, Kobayashi T, Mukai T, et al. The activity of non-basal slip systems and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys [J]. Acta Mater., 2003, 51: 2055
doi: 10.1016/S1359-6454(03)00005-3
35
Jain J, Cizek P, Hariharan K. Transmission electron microscopy investigation on dislocation bands in pure Mg [J]. Scr. Mater., 2017, 130: 133
doi: 10.1016/j.scriptamat.2016.11.035
36
Geng J, Chisholm M F, Mishra R K, et al. An electron microscopy study of dislocation structures in Mg single crystals compressed along [0001] at room temperature [J]. Philos. Mag., 2015, 95: 3910
doi: 10.1080/14786435.2015.1108531
37
Liu B Y, Liu F, Yang N, et al. Large plasticity in magnesium mediated by pyramidal dislocations [J]. Science, 2019, 365: 73
doi: 10.1126/science.aaw2843
38
Wu Z X, Curtin W A. The origins of high hardening and low ductility in magnesium [J]. Nature, 2015, 526: 62
doi: 10.1038/nature15364
39
Ahmad R, Yin B L, Wu Z X, et al. Designing high ductility in magnesium alloys [J]. Acta Mater., 2019, 172: 161
doi: 10.1016/j.actamat.2019.04.019
40
Wu Z X, Ahmad R, Yin B L, et al. Mechanistic origin and prediction of enhanced ductility in magnesium alloys [J]. Science, 2018, 359: 447
doi: 10.1126/science.aap8716
pmid: 29371467
41
Feng Z Q, Fu R, Lin C W, et al. TEM-based dislocation tomography: Challenges and opportunities [J]. Curr. Opin. Solid State Mater. Sci., 2020, 24: 100833
doi: 10.1016/j.cossms.2020.100833
