Article
Microstructure and Mechanical Properties of Al-Mg-Si Similar
Alloy Laminates Produced by Accumulative Roll Bonding
Zhigang Li, Hao Jiang, Minghui Wang, Hongjie Jia, Hongjiang Han and Pinkui Ma *
Citation: Li, Z.; Jiang, H.; Wang, M.;
Jia, H.; Han, H.; Ma, P. Microstructure
and Mechanical Properties of
Al-Mg-Si Similar Alloy Laminates
Produced by Accumulative Roll
Bonding. Materials 2021, 14, 4200.
https://doi.org/10.3390/
ma14154200
Academic Editor: Arkadiusz Gola
Received: 27 June 2021
Accepted: 25 July 2021
Published: 27 July 2021
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4.0/).
Key Laboratory of Automotive Materials Ministry of Education, School of Material Science and Technology,
Jilin University, Changchun 130022, China; lzg@jlu.edu.cn (Z.L.); jianghao18@mails.jlu.edu.cn (H.J.);
minghui@jlu.edu.cn (M.W.); jiahj@jlu.edu.cn (H.J.); hanhj@jlu.edu.cn (H.H.)
* Correspondence: mapk@jlu.edu.cn
Abstract:
As the applications of heterogeneous materials expand, aluminum laminates of similar
materials have attracted much attention due to their greater bonding strength and easier recycling.
In this work, an alloy design strategy was developed based on accumulative roll bonding (ARB) to
produce laminates from similar materials. Twin roll casting (TRC) sheets of the same composition
but different cooling rates were used as the starting materials, and they were roll bonded up to three
cycles at varying temperatures. EBSD showed that the two TRC sheets deformed in distinct ways
during ARB processes at 300
◦
C. Major recrystallizations were significant after the first cycle on
the thin sheet and after the third cycle on the thick sheet. The sheets were subject to subsequent
aging for better mechanical properties. TEM observations showed that the size and distribution
of nano-precipitations were different between the two sheet sides. These nano-precipitations were
found to significantly promote precipitation strengthening, and such a promotive effect was referred
to as hetero-deformation induced (HDI) strengthening. Our work provides a new promising method
to prepare laminated heterogeneous materials with similar alloy TRC sheets.
Keywords: Al-Mg-Si alloy; accumulative roll bonding; aging treatment; heterogeneous materials
1. Introduction
Aluminum (Al) and its alloys are extensively used in aerospace and automobile
industries due to their high specific strength, good formability, and low price [
1
]. For
decades, numerous researchers have attempted to improve the mechanical properties of
aluminum alloys, thereby further extending their scope of applications [
1
,
2
]. However, an
increase in the strength of traditional materials (e.g., Al and its alloys) often comes at the
cost of lower plasticity.
As a type of emerging structural material, heterogeneous materials present outstand-
ing performance [
3
]. Since microstructure formation of dissimilar laminates was controlled
by the hetero-deformation between the harder and softer layers, the strength of heteroge-
neous materials can be improved through the hetero-deformation-induced (HDI) hardening
mechanism with almost no loss of plasticity. Therefore, overcoming the limitations of tra-
ditional strengthening mechanisms that are difficult to balance between strength and
plasticity [
3
,
4
]. Accumulative roll bonding (ARB), a traditional technique of severe plastic
deformation (SPD), is easily adopted by the industry because it does not need any major
modifications to the conventional equipment design [
5
]. Since the birth of heterogeneous
materials, ARB has been used to produce laminated composites [6] and metal-based com-
posites with oxide particles [
7
,
8
]. Furthermore, thanks to the development of heterogeneous
materials, ARB has been used to simultaneously process two or more different materials
and produce laminate composites with special properties, such as Al/Mg [
6
], Al/Ti [
9
],
Mg/Nb [
10
], and Cu/Nb [
11
]. However, dissimilar metals tend to form brittle phases at
the interface, which is not conducive to good bonding. Besides, the composites made from
Materials 2021, 14, 4200. https://doi.org/10.3390/ma14154200 https://www.mdpi.com/journal/materials
