Al laminates

Accepted Manuscript A coupled EBSD/TEM study on the interfacial structure of Al/Mg/Al laminates Huihui Nie, Wei Liang, Hongsheng Chen, Fei Wang, Taotao Li, Chengzhong Chi, Xian rong Li PII:

S0925-8388(18)34498-0

DOI:

https://doi.org/10.1016/j.jallcom.2018.11.366

Reference:

JALCOM 48592

To appear in:

Journal of Alloys and Compounds

Received Date: 16 July 2018 Revised Date:

23 October 2018

Accepted Date: 27 November 2018

Please cite this article as: H. Nie, W. Liang, H. Chen, F. Wang, T. Li, C. Chi, X.r. Li, A coupled EBSD/ TEM study on the interfacial structure of Al/Mg/Al laminates, Journal of Alloys and Compounds (2018), doi: https://doi.org/10.1016/j.jallcom.2018.11.366. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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ACCEPTED MANUSCRIPT A coupled EBSD/TEM study on the interfacial structure of Al/Mg/Al laminates Huihui Nie

a,b

, Wei Liangb,c,*, Hongsheng Chen

a,b

, Fei Wangd, Taotao Lib,c,

Chengzhong Chib,c,Xian rong Lib,c College of Mechanical and Vehicle Engineering, Taiyuan University of Technology,

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a

Taiyuan 030024, PR China

Shanxi Key Laboratory of Advanced Magnesium-based Materials, Taiyuan

University of Technology, Taiyuan 030024, PR China

College of Materials Science and Engineering, Taiyuan University of Technology,

Taiyuan 030024, PR China

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Shanxi Institute of Energy, Taiyuan 030006, PR China

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d

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c

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b

ACCEPTED MANUSCRIPT ABSTRACT: Al/Mg/Al laminate was fabricated by four-pass rolling with a total rolling reduction of 71% followed by annealing at 200oC for 1h. Intermetallics identified as

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Mg17Al12 and Al3Mg2 were observed at Mg/Al interface, both of which exhibit columnar grains due to element interdiffusion between the component layers. EBSD and TEM were employed to characterize the orientation of interfaces of Mg/Mg17Al12,

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Mg17Al12/Al3Mg2 and Al3Mg2/Al, and the results show the three interfaces all present

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the coherent relation with small mismatch degrees ranging from 0.64% to 2.7%. Besides, Mg layer in annealed Al/Mg/Al laminates is mainly composed of equiaxed grains with the average size around 4 µm due to recrystallization after annealing. Typical (0002) basal texture is found in Mg layer with the maximum pole intensity of

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9.86. By contrast, deformation bands are obvious in Al layer and a small amount of fine recrystallized grains appear between the deformation bands. The ultimate tensile strength (UTS) and elongation of Al/Mg/Al laminate are slightly higher than that of

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original Mg sheet. Delamination appears during the tensile process of Al/Mg/Al

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laminate, and fractures mainly propagate among the intermetallics at Mg/Al interface.

Keywords: Al/Mg/Al laminate; interface; intermetallics; texture; coherent relation __________________ * Corresponding author. Tel.: +86 351 6018398. E-mail: [email protected] (W. Liang)

ACCEPTED MANUSCRIPT 1. Introduction Multi-layered metal sheets recently have attracted much attention due to their excellent and comprehensive mechanical properties [1-2]. Except for the traditional

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metal materials like stainless steels and copper, Al/Mg/Al laminates with the advantages both of lightweight Mg and anticorrosive Al have extensive application in a variety of industrial fields including mechanics, electronics, automotive and

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aerospace [3]. Despite the merits of Mg alloys, traditional working process at room

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temperature is hindered by the limited ductility due to their hexagonal close packed (hcp) crystal structure [4]. Hence, hot rolling as an efficient and profitable hot-working process is often adopted to enhance plasticity via thermal activation of hard slip modes and dynamic recrystallization [5].

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The microstructures of both the matrix and intermetallics formed at the Mg/Al interface have a significant effect on the bonding strength and mechanical properties of the laminates [6-7]. Subsequent heat treatment or rolling influencing the thickness,

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morphology and distribution of intermetallics are often adopted because mechanical

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interlocking and/or metallurgical bonding at Mg/Al interface are insufficient to meet the requirement of practical use [8]. However, few information on the orientation between the matrix and intermetallics are reported, as well as the orientation between the different intermetallics. Therefore, in this paper, the relation of the matrix and the intermetallics are the main concerns. Besides, the textures of Mg and Al as component layers are also discussed. 2. Experimental detail

ACCEPTED MANUSCRIPT The Al/Mg/Al laminate was fabricated by four-pass hot rolling at 400oC with a total rolling reduction of 71%. The component sheets are commercial AZ31 and 5052 sheet with the original thickness 2.7 mm and 0.4 mm, respectively, and the chemical

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compositions (wt. %) are summarized in Table 1. Table 1. Chemical constituents of 5052 and AZ31 (wt. %) Cr

5052

2.2~2.8

0.15~0.35

AZ31

balance

-

Ni

Fe

Mn

Si

-

0.40

0.10

0.25

0.005

0.50

0.005

Cu

Zn

Al

0.10

0.10

Balance

-

0.90

3.01

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Mg

0.04

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Material

The subsequent annealing is necessary to reduce the detrimental effect of residual stress and strong rolling texture. Temperature and holding time have a great influence on element diffusion speed at the Mg/Al interface. Plenty of research on

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Mg/Al laminates have shown that the amount of intermetallics generally increases with increasing temperature and holding time, which is adverse to the mechanical properties and bonding strength of the laminates [9-12]. Intermetallics rapidly grow at

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the Mg/Al interface when the annealing temperature is above 220~250 oC. However,

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the effect of extending holding time on intermetallics is not obvious when the temperature is below 200 oC [12]. Therefore, the rolled Al/Mg/Al laminate in this paper was annealed at 200 oC for 1 h. The following tests are illustrated in Fig. 1. Samples were taken from the annealed laminate. The microstructures were characterized on a Tescan Mira 3 Field Emission Scanning Electron Microscope (SEM) equipped with an Oxford EDS and an Oxford electron backscatter diffraction (EBSD) system. The testing plane of EBSD

ACCEPTED MANUSCRIPT was RD*ND, and the measurement was taken at 20 kV with a 15 mm working distance, a tilt angle of 70o, and a scanning step of 0.4 mm. The crystallographic orientation of the grains was analyzed, using channel 5 software. Besides, JEOL

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2100F transmission electron microscope (TEM) was also employed to achieve further microstructural observation, and the TEM sample was cut using LYRA 3 XMH Focused Ion Beam (FIB). To identify the phases at the Mg/Al interface, the Al/Mg/Al

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laminate was split along Mg/Al interface, and a Tongda TD-3000 x-ray diffraction

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(XRD) was used and the testing plane was shown in Fig. 1.

Fig.1 The schematic diagram of testing of Al/Mg/Al laminate

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Besides, the mechanical properties of Al/Mg/Al laminate and the original Mg

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sheet were tested on an electronic universal testing machine (DNS 200) in the displacement-control mode and with a crosshead speed of 0.5 mm/min. The tensile samples were cut from the laminates along the RD. 3. Results and discussion 3.1 Grains of matrix and intermetallics AZ31 layer is mainly composed of equiaxed grains with the average size around 4 µm due to recrystallization after annealing, which are more uniform than Al grains,

ACCEPTED MANUSCRIPT as shown in Fig. 2a. Elongated grains with nonuniform size dominate the 5052 layer and a small amount of fine grains appear between the deformation bands. The reason for the huge difference in grain morphology of Mg and Al is that 200oC is suitable for

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rolled AZ31 to activate recrystallization, but it is much lower than the recrystallization temperature of Al around 350oC [13]. Full recrystallization can enhance the comprehensive mechanical properties of deformed sheets through reducing the

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dislocation density and residual stress of materials interior [14-16]. Therefore,

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annealing Al/Mg/Al laminate at 200 oC is suitable because Mg layer with a larger volume fraction of the laminate plays a more important part in improving mechanical

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property of Al/Mg/Al laminate than the thinner Al layer.

Fig.2 Micrographs of Al/Mg/Al laminates and distribution of elements at the

ACCEPTED MANUSCRIPT Mg/Al interface Obviously, two layers distinguished by different contrasts appeared at the Mg/Al interface, as shown in Fig. 2a, which indicates new phases formed during the

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fabrication process. The atomic percentages of Mg and Al at point A are 41.1% and 58.9% (Fig. 2b), respectively, and point B are 59.5% and 40.1% (Fig. 2c). Combining the element scanning results and Mg-Al binary phase graph [17] and previous

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literatures [18-19], it can be deduced that the intermetallics are Mg17Al12 and Al3Mg2.

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And the speculation about the intermetallics is proved by the XRD results in Fig. 3, which shows strong peaks of α-Al along with Al3Mg2 phases on Al side; and on Mg

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side, peaks of α-Mg along with Mg17Al12 and Al3Mg2 phases are evident.

Fig.3 XRD results of peeling surfaces from Mg/Al interface 3.2 Orientation of component layers Fig. 4 shows the inverse pole figure (IPF), pole figure (PF) and distribution of grain boundary misorientation of the component Mg and Al layers. Fig. 5 is provided

ACCEPTED MANUSCRIPT to intuitively understand the recrystallization behavior of Al/Mg/Al laminate, in which recrystallized, substructured and large deformed grains are marked by blue, yellow and red colors, respectively.

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It can be seen from Fig. 4c that the average value of misorientation angle of Al layer is 13o, indicating low angle grain boundaries (LAGBs) between 2o and 15o take a large proportion. LAGBs are often associated with dislocation, and the large

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dislocation density of Al layer is induced by the rolling process and not eliminated

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during the annealing process. This phenomenon accords with the morphology in Fig. 2a and the summary statistics of recrystallized number fraction in Al layer in Fig. 5b. Fig. 5b shows that the large deformed grains and the substructured grains account for 71% and 21% in Al layer, respectively, while few recrystallized grains are observed.

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The small fraction of blue recrystallized grains in Al layer in Fig. 5a scatter around the deformation bands, so both the dynamic recrystallization caused by large strain along the ND and the recrystallization caused by subsequent annealing can be the reasons.

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(111) PF of Al is close to the copper texture, which has a rotation angle compared

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with the typical rolling copper texture of rolled Al single layer. By contrast, the average misorientation angle of Mg is 39o (Fig. 4e), which is

much higher than that of Al, suggesting deformation storage energy is partly released through recovery and recrystallization in the subsequent annealing. The peak value of misorientation angle of Mg is about 30o, which can be commonly observed in recrystallized Mg alloys [20].The peak value of misorientation angle approaches the average, indicating Mg layer achieves extensive recrystallization. This is consistent

ACCEPTED MANUSCRIPT with the 67% of recrystallized grains in Mg layer in Fig. 5b. High angle grain boundaries (HAGBs) larger than 15o in Fig. 4e dominate in the Mg layer, while the LAGBs occupy a small percentage. Besides, the Mg layer exhibits typical (0002)

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basal texture, and the maximum pole intensity is 9.86 in Fig. 4d, which is much smaller than that of as-rolled Mg sheets reported in previous literature [21]. This result further proves that a majority of Mg grains recrystallized during the annealing

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process.

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It can be seen that the intermetallics of Mg17Al12 and Al3Mg2 are not clearly identified in Fig. 4a, because the huge difference in physical and chemical properties among the Mg, Al, Mg17Al12 and Al3Mg2 layers. However, except for the orientation of matrix, the orientation between the matrix and intermetallics also has a significant

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effect on the mechanical properties of the laminates. Therefore, the orientation

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between metal matrix and the intermetallics shall be elaborated in the next section.

Fig.4 (a) IPF of Al/Mg/Al laminate; (b) and (c) PF and misorientation of Al layer;

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(d) and (e) PF and misorientation of Mg layer

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Fig.5 Recrystallization of Al/Mg/Al laminate: (a) IPF; (b) number fraction 3.3 Orientation between matrix and the intermetallics

Fig. 6 illustrates the morphology of TEM sample by using FIB. Three kinds of phase interfaces are Al/Al3Mg2, Al3Mg2/Mg17Al12 and Mg17Al12/Mg, respectively. To

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facilitate writing, they are denoted as A, B and C in turn and marked by black boxes. The dark region marked by arrow is not the interface of Al3Mg2 and Mg17Al12, it is a

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relative thick zone working as a rib reinforcement to prevent bending or breaking.

Fig.6 TEM sample prepared by FIB

ACCEPTED MANUSCRIPT Fig. 7 is the morphology, fast Fourier transform (FFT) and the high resolution transmission (HRTEM) of the phase interfaces A, B and C. It can be seen from the Fig. 7a that the phase interface of Al and Al3Mg2 is clean and well-bonded, and pores,

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microvoids and amorphous layer are not observed. Interface A exhibits a wavy structure, which is in accord with that in Fig. 2a.The interplanar spacing can be found in Fig. 7c, so the orientation relationship of interface A can be described as (1), and

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the mismatch δ can be generated as (2). The result of 0.7% shows little lattice misfit

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strain at the interface and can be considered as a coherent interface. Meanwhile, it also suggests a good interface bonding between Al3Mg2 and Al matrix.

11 ，) Al Mg {220}Al // (19， 3

δ=

(1)

2

0.1433 − 0.1423 × 100% = 0.70% 0.1433

(2)

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Fig. 7d presents the morphology of interface B with a curve and well-bonded shape. Likewise, pores, microvoids and amorphous layer are not observed. The

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selected area (SA) diffraction patterns of Al3Mg2 and Mg17Al12 are given in Fig. 7e and Fig. 7f. The results can help to identify the interfacial phases as Al3Mg2 and

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Mg17Al12, respectively, and it is consistent with the results of Fig. 2(b and c) and Fig. 3. Both of the Al3Mg2 and Mg17Al12 grains are in columnar shape along their growing direction (ND), which is also the element interdiffusion direction during the intermediate heating between the rolling passes. This phenomenon is different from the profiles of intermetallics of hot rolled AZ31/3004Al, in which a columnar growth is observed only in the Mg17Al12 layer, but not in the Al3Mg2 layer [22]. The annealing and rolling temperatures would be responsible for this difference. From the

ACCEPTED MANUSCRIPT corresponding FFT (Fig. 7g) and HRTEM (Fig. 7h), the orientation relationship of interface B can be summarized as (3) and the mismatch δ can be calculated as (4). Thus, coherent relation is also found at interface B. To further explain the orientation

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of interface B, the atomic arrangement schematic diagram is given in Fig.8. Obviously, both of the Mg17Al12 and Al3Mg2 are complex cubic structures, and the parallel crystal faces are labeled below. The results are consistent with that in Fig.7. // (141) Mg

17 Al12

， ( 808 ) Al Mg // ( 411) Mg 3

2

0.2496 − 0.2480 × 100% = 0.64% 0.2496

17 Al12

(3)

(4)

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δ=

Al3Mg2

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(880)

A well-bonded interface C is illustrated in Fig. 7i, and one Mg17Al12 grain grows from the interior of AZ31 matrix, indicating high interfacial energy in local areas promotes the growth of Mg17Al12 through atomic diffusion and crystal boundary

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migration. Moreover, the orientation relationship of interface C can be summarized as (5) and the mismatch can be calculated as (6). It is clear that the mismatch of interface

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C is higher than that of A and B, but 2.7% mismatch can still be considered as coherent relation. //

{411}Mg

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( 0111 ) δ=

Mg

17 Al12

0.2465 − 0.2398 × 100% = 2.7% 0.2465

(5) (6)

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Fig.7 TEM results of Al/Mg/Al interface

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Fig.8 Atomic arrangement schematic diagram of interface B 3.4 Mechanical properties

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Fig. 9 shows the engineering stress-strain curves of Al/Mg/Al laminate and original Mg sheet. The ultimate stress (UTS) and elongation to fracture (EF) of

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laminate are about 216 MPa and 14.8%, respectively. UTS and EF of original Mg sheet are a little smaller than that of laminate. The obvious difference between Mg

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sheet and Al/Mg/Al laminate appears at the later period of uniform plastic deformation. For the laminate, there is a slight decrease when the engineering strain reaches 13%, which is due to the delamination at Mg/Al interface and is consistent with the fracture morphology. It can be seen that cracks propagate among the intermetallics, which are hard and brittle [23]. However, the original Mg sheet shows a direct breakage after uniform plastic deformation.

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4. Conclusion

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Fig. 9 Engineering stress-strain curves of Al/Mg/Al laminate and original Mg sheet

The hot-rolled Al/Mg/Al laminate with 71% rolling reduction was annealed at

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200oC for 1h, and its microstructure, especially the orientation of component layers,

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and between the matrix and the intermetallics were characterized. The following conclusions can be drawn: (1) Mg layer is mainly composed of equiaxed grains with the average size

around 4 µm due to recrystallization after annealing, while the elongated grains with nonuniform size dominant the Al layer and a small amount of fine grains appear around deformation bands. The intermetallics at the Mg/Al interface are Mg17Al12 and Al3Mg2, respectively.

ACCEPTED MANUSCRIPT (2) The Mg layer exhibits typical (0002) basal texture, and HAGBs take a dominant position with the maximum intensity of 9.86 and the average misorientation angel is 39o. The texture of Al layer is to the copper type, and the average

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misorientation angle is much lower than that of Mg due to small recrystallization extent.

(3) The phase interfaces Al/Al3Mg2, Al3Mg2/Mg17Al12 and Mg17Al12/Mg all

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present the coherent relationship with small mismatch degrees ranging from 0.64% to

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2.7%. Both Mg17Al12 and Al3Mg2 layer show columnar grains along the ND, which is the element interdiffusion direction during the intermediate heating between the rolling passes.

(4) The UTS and elongation of Al/Mg/Al laminate are slightly higher than that of

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original Mg sheet. Delamination appears during the tensile process of Al/Mg/Al laminate, and fractures mainly propagate among the intermetallics at Mg/Al interface.

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Acknowledgements

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This study was supported by the National Natural Science Foundation of China under Grant No. 51274149, No. 51474152, No. U1710254 and No. 181020018; Shanxi Province major science and technology projects under Grant No. 20181101008 Shanxi Institute of Energy under Grant No. ZY-2017003.

References [1] S. Lyu, Y. Sun, L. Ren, W. Xiao, C. Ma, Simultaneously achieving high tensile

ACCEPTED MANUSCRIPT strength and fracture toughness of Ti/Ti-Al multilayered composites, Intermetallics. 90 (2017) 16-22. [2]

M.

Alizadeh,

M.

K.

Dashtestaninejad,

Development

of

Cu-matrix,

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Al/Mn-reinforced, multilayered composites by accumulative roll bonding (ARB), J. Alloy. Comp. 732 (2018) 674-682.

[3] X. Qiao, X. Li, X. Zhang, Y. Chen, M. Zheng, I.S. Golovinc, N. Gao, M. J. Starink,

SC

Intermetallics formed at interface of ultrafine grained Al/Mg bi-layered disks

187-190.

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processed by high pressure torsion at room temperature, Mater. Letters. 181 (2016)

[4] M. Steiner, J.J. Bhattacharyya, S.R. Agnew, The origin and enhancement of {0001} <11-20> texture during heat treatment of rolled AZ31B magnesium alloys, Acta.

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Mater. 95 (2015) 674-682.

[5] F. Guo, D. Zhang, X. Fan, X. Jiang, L. Yu, F. Pan, Deformation behavior of AZ31 Mg alloys sheet during large strain hot rolling process: A study on microstructure and

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140-147.

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texture evolutions of an intermediate-rolled sheet, J. Alloy. Comp. 663 (2016)

[6] K. Park, J. Park, H. Kwon, Effect of intermetallic compound on the Al-Mg composite materials fabricated by mechanical ball milling and spark plasma sintering, J. Alloy. Comp.739 (2018) 311-318. [7] Y. Zhao, Z. Ding, Y. Chen, Crystallographic orientations of intermetallic compounds of a multi-pass friction stir processed Al/Mg composite materials, Mater. Chara. 128 (2017) 156–164.

ACCEPTED MANUSCRIPT [8] A. Macwan, X. Q. Jiang, C. Li, D. L. Chen, Effect of annealing on interface microstructures and tensile properties of rolled Al/Mg/Al tri-layer clad sheets, Mater. Sci. Eng. A.587 (2013) 344-351.

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[9] J.H. Bae, A.K. Prasada Rao, K.H. Kim, N.J. Kim, Cladding of Mg alloy with Al by twin roll casting, Scr. Mater. 64 (2011) 836–839.

[10] A. Kostka, R.S. Coelho, J.D. Santos, A.R. Pyzalla, Microstructure of friction stir

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welding of aluminium alloy to magnesium alloy, Scr. Mater. 62 (2009) 953–956.

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[11] Y.D. Zhao, Z.M. Ding, C.B. Shen, Y. Chen, Interfacial microstructure and properties of aluminum-magnesium AZ31B multi-pass friction stir processed composite plate, Mater. Des. 94 (2016) 240–252.

[12] C. Luo, W. Liang, Z. Chen, Z. Chi, F. Yang, Effect of high temperature annealing

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and subsequent hot rolling on microstructural evolution at the bond-interface of Al/Mg/Al alloy laminated composites, Mater. Chara. 84 (2013) 34-40. [13] M. Z. Quadir, N. Najafzadeh, P. R. Munroe, Variations in through-thickness

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recrystallization and grain growth textures in the Al layers in ARB-processed Al/Al

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(0.3% Sc) composite sheets, Mater. Des. 93 (2016) 467-473. [14] R. Zheng, T. Bhattacharjee, A. Shibata, T. Sasaki, K. Hono, M. Joshi, N. Tsuji, Simultaneously enhanced strength and ductility of Mg-Zn-Zr-Ca alloy with fully recrystallized ultrafine grained structures, Scri. Mater. 131 (2017) 1-5. [15] Z. R. Zeng, Y. M. Zhu, S. W. Xu, M.Z. Bian, C. H. J. Davies, N. Birbilis, J. F. Nie, Texture evolution during static recrystallization of cold-rolled magnesium alloys, Acta. Mater. 105 (2016) 479-494.

ACCEPTED MANUSCRIPT [16] W. Cheng, L. Wang, H. Zhang, X. Cao, Enhanced stretch formability of AZ31 magnesium alloy thin sheet by pre-crossed twinning lamellas induced static recrystallizations, J. Mater. Pro. Tech. 254 (2018) 302-309.

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[17] M. C. Chen, C. C. Hsieh, W. Wu, Microstructural characterization of Al/Mg alloy interdiffusion mechanism during Accumulative Roll Bonding, Metals. Mater. Inter. 13 (2007) 201-205.

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[18] E. Hajjari, M. Divandari, S. H. Razavi, T. Homma, S. Kamado, Intermetallic

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compounds and antiphase domains in Al/Mg compound casting, Intermetallics. 23 (2012) 182-186.

[19] L. Chen, J. Tang, G. Zhao, C. Zhang, X. Chu, Fabrication of Al/Mg/Al laminate by a porthole die co-extrusion process, J. Mater. Pro. Tech. 258 (2018) 165-173.

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[20] J. C. Tan, M. J. Tan, Dynamic continuous recrystallization characteristics in two stage deformation of Mg-3Al-1Zn alloy sheet, Mater. Sci. Eng. A. 558 (2012) 510– 516.

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[21] Xia, D., Huang, G., Deng, Q., Jiang, B., Liu, S., & Pan, F. Influence of stress

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state on microstructure evolution of AZ31 mg alloy rolled sheet during deformation at room temperature. Mater. Sci. Eng A. 715 (2018) 379-388. [22] J. S. Kim, K. S. Lee, N. K. Yong, B. Lee, Y. W. Chang, S. Lee, Improvement of interfacial bonding strength in roll-bonded Mg/Al clad sheets through annealing and secondary rolling process. Mater. Sci. Eng A. 628 (2015) 1-10. [23] Park, K., Park, J., & Kwon, H. Effect of intermetallic compound on the al-mg composite materials fabricated by mechanical ball milling and spark plasma sintering.

ACCEPTED MANUSCRIPT J Alloy. Comp. 739 (2018) 311-318.

Table captions:

Figure captions:

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Fig.1 The schematic diagram of testing of Al/Mg/Al laminate

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Table 1. Chemical constituents of 5052 and AZ31 (wt. %)

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Fig.2 Micrographs of Al/Mg/Al laminates and distribution of elements at the Mg/Al interface

Fig.3 XRD results of peeling surfaces from Mg/Al interface

Fig.4 (a) IPF of Al/Mg/Al laminate; (b) and (c) PF and misorientation of Al layer;

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(d) and (e) PF and misorientation of Mg layer

Fig.5 Recrystallization of Al/Mg/Al laminate: (a) IPF; (b) number fraction Fig.6 TEM sample prepared by FIB

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Fig.7 TEM results of Al/Mg/Al interface

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Fig.8 Atomic arrangement schematic diagram of interface B Fig. 9 Engineering stress-strain curves of Al/Mg/Al laminate and original Mg sheet

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Highlights


Intermetallics identified as Mg17Al12 and Al3Mg2 exhibit columnar grains.




Interfaces Mg/Mg17Al12, Mg17Al12/Al3Mg2 and Al3Mg2/Al present coherent




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relation. Mg layer is composed of equiaxed grains and exhibits typical (0002) basal texture.

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Deformed and nonuniform grains dominant Al layer with copper type.

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