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Asymmetric accumulative roll bonding of aluminium-titanium composite sheets

Ng, Hoi Pang; Przybilla, Thomas; Schmidt, Christian; Lapovok, Rimma; Orlov, Dmitry; Höppel, Heinz Werner and Göken, Mathias (2013) In Materials Science & Engineering: A 576. p.306-315
Abstract

Aluminium-titanium (Al/Ti) composite sheets were fabricated via asymmetric accumulative roll bonding (AARB), which capitalises on additional shear to enhance plastic deformation. Multi-layers of Al alloy (AA1050) and commercially-pure Ti sheets were alternatively stacked and rolled-bonded with varied roll diameter ratios (dr) ranging from 1 to 2, for up to four passes. Annealing of selected composite sheets was subsequently carried out at 600°C for 24h to compare the rates of solid-state diffusion reactions between Al and Ti components. Mechanical tests revealed that both tensile strength and ductility of the sheets increase systematically with dr. The microstructures and the Al/Ti interfaces of the sheets were... (More)

Aluminium-titanium (Al/Ti) composite sheets were fabricated via asymmetric accumulative roll bonding (AARB), which capitalises on additional shear to enhance plastic deformation. Multi-layers of Al alloy (AA1050) and commercially-pure Ti sheets were alternatively stacked and rolled-bonded with varied roll diameter ratios (dr) ranging from 1 to 2, for up to four passes. Annealing of selected composite sheets was subsequently carried out at 600°C for 24h to compare the rates of solid-state diffusion reactions between Al and Ti components. Mechanical tests revealed that both tensile strength and ductility of the sheets increase systematically with dr. The microstructures and the Al/Ti interfaces of the sheets were analysed in detail using TEM, SEM and FIB techniques. It is shown that not only does AARB lead to a more refined grain size of the Al matrix but also it promotes the development of a nanostructured surface layer on Ti that comprises crystallites of 50-100nm in size, which is otherwise absent in the case of symmetric ARB (i.e. dr=1). The AARB-processed sheets exhibit a larger thickness of the interdiffusion layer at the Al/Ti interfaces than the counterparts processed via the symmetric ARB route, the difference being in excess of 15%. The effects and the implications of AARB processing on mechanical behaviour and diffusion kinetics are discussed with respect to the microstructural evolutions.

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author
publishing date
type
Contribution to journal
publication status
in press
subject
keywords
Al-Ti, Asymmetric accumulative roll bonding, Diffusion, Mechanical properties, Transmission electron microscopy
in
Materials Science & Engineering: A
volume
576
pages
10 pages
publisher
Elsevier
external identifiers
  • scopus:84877075055
ISSN
0921-5093
DOI
10.1016/j.msea.2013.04.027
language
English
LU publication?
no
id
4396f534-351c-4222-9a5b-52b41bff89fd
date added to LUP
2016-06-20 15:58:12
date last changed
2018-01-07 11:18:23
@article{4396f534-351c-4222-9a5b-52b41bff89fd,
  abstract     = {<p>Aluminium-titanium (Al/Ti) composite sheets were fabricated via asymmetric accumulative roll bonding (AARB), which capitalises on additional shear to enhance plastic deformation. Multi-layers of Al alloy (AA1050) and commercially-pure Ti sheets were alternatively stacked and rolled-bonded with varied roll diameter ratios (d<sub>r</sub>) ranging from 1 to 2, for up to four passes. Annealing of selected composite sheets was subsequently carried out at 600°C for 24h to compare the rates of solid-state diffusion reactions between Al and Ti components. Mechanical tests revealed that both tensile strength and ductility of the sheets increase systematically with d<sub>r</sub>. The microstructures and the Al/Ti interfaces of the sheets were analysed in detail using TEM, SEM and FIB techniques. It is shown that not only does AARB lead to a more refined grain size of the Al matrix but also it promotes the development of a nanostructured surface layer on Ti that comprises crystallites of 50-100nm in size, which is otherwise absent in the case of symmetric ARB (i.e. d<sub>r</sub>=1). The AARB-processed sheets exhibit a larger thickness of the interdiffusion layer at the Al/Ti interfaces than the counterparts processed via the symmetric ARB route, the difference being in excess of 15%. The effects and the implications of AARB processing on mechanical behaviour and diffusion kinetics are discussed with respect to the microstructural evolutions.</p>},
  author       = {Ng, Hoi Pang and Przybilla, Thomas and Schmidt, Christian and Lapovok, Rimma and Orlov, Dmitry and Höppel, Heinz Werner and Göken, Mathias},
  issn         = {0921-5093},
  keyword      = {Al-Ti,Asymmetric accumulative roll bonding,Diffusion,Mechanical properties,Transmission electron microscopy},
  language     = {eng},
  month        = {08},
  pages        = {306--315},
  publisher    = {Elsevier},
  series       = {Materials Science & Engineering: A},
  title        = {Asymmetric accumulative roll bonding of aluminium-titanium composite sheets},
  url          = {http://dx.doi.org/10.1016/j.msea.2013.04.027},
  volume       = {576},
  year         = {2013},
}