Advanced

Ductilization of aluminium alloy 6056 by friction stir processing

Hannard, F.; Castin, S.; Maire, E.; Mokso, R. LU ; Pardoen, T. and Simar, A. (2017) In Acta Materialia 130. p.121-136
Abstract

The ductility of Al alloys is dictated by the nucleation, growth and coalescence of small internal voids originating from intermetallic particle fracture and from the presence of pre-existing porosity. The ductility is degraded when intermetallic particles are large and clustered. A low ductility adversely impacts both forming operations and the integrity of structural components. Local stirring using a friction stir processing (FSP) tool is shown here to very significantly increase the fracture strain of the Al alloy 6056 sometimes by more than a factor of two while making it more isotropic. Three reasons for the ductilization are unravelled based on 3D microtomography: (i) FSP breaks the large intermetallic particles into smaller, and... (More)

The ductility of Al alloys is dictated by the nucleation, growth and coalescence of small internal voids originating from intermetallic particle fracture and from the presence of pre-existing porosity. The ductility is degraded when intermetallic particles are large and clustered. A low ductility adversely impacts both forming operations and the integrity of structural components. Local stirring using a friction stir processing (FSP) tool is shown here to very significantly increase the fracture strain of the Al alloy 6056 sometimes by more than a factor of two while making it more isotropic. Three reasons for the ductilization are unravelled based on 3D microtomography: (i) FSP breaks the large intermetallic particles into smaller, and thus stronger, fragments, (ii) FSP closes the pre-existing porosity; (iii) FSP randomizes the particle distribution. Hence, FSP positively impacts three of the main causes of ductility loss in metallic alloys. From an applicability viewpoint, this method has the potential to locally improve ductility of sheets at locations where forming involves large strains or of structural components at stress concentration points.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aluminium alloys, Ductile damage, Friction stir processing, Tomography
in
Acta Materialia
volume
130
pages
16 pages
publisher
Elsevier
external identifiers
  • scopus:85015863199
  • wos:000401388700011
ISSN
1359-6454
DOI
10.1016/j.actamat.2017.01.047
language
English
LU publication?
yes
id
1328c225-eb1d-4148-90e9-5b3c3f2bd36d
date added to LUP
2017-04-05 07:47:41
date last changed
2018-01-14 04:31:25
@article{1328c225-eb1d-4148-90e9-5b3c3f2bd36d,
  abstract     = {<p>The ductility of Al alloys is dictated by the nucleation, growth and coalescence of small internal voids originating from intermetallic particle fracture and from the presence of pre-existing porosity. The ductility is degraded when intermetallic particles are large and clustered. A low ductility adversely impacts both forming operations and the integrity of structural components. Local stirring using a friction stir processing (FSP) tool is shown here to very significantly increase the fracture strain of the Al alloy 6056 sometimes by more than a factor of two while making it more isotropic. Three reasons for the ductilization are unravelled based on 3D microtomography: (i) FSP breaks the large intermetallic particles into smaller, and thus stronger, fragments, (ii) FSP closes the pre-existing porosity; (iii) FSP randomizes the particle distribution. Hence, FSP positively impacts three of the main causes of ductility loss in metallic alloys. From an applicability viewpoint, this method has the potential to locally improve ductility of sheets at locations where forming involves large strains or of structural components at stress concentration points.</p>},
  author       = {Hannard, F. and Castin, S. and Maire, E. and Mokso, R. and Pardoen, T. and Simar, A.},
  issn         = {1359-6454},
  keyword      = {Aluminium alloys,Ductile damage,Friction stir processing,Tomography},
  language     = {eng},
  month        = {05},
  pages        = {121--136},
  publisher    = {Elsevier},
  series       = {Acta Materialia},
  title        = {Ductilization of aluminium alloy 6056 by friction stir processing},
  url          = {http://dx.doi.org/10.1016/j.actamat.2017.01.047},
  volume       = {130},
  year         = {2017},
}