dc.contributor.author
Oddone, Valerio
dc.contributor.author
Wimpory, Robert C.
dc.contributor.author
Reich, Stephanie
dc.date.accessioned
2019-09-06T07:09:45Z
dc.date.available
2019-09-06T07:09:45Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/25431
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-4135
dc.description.abstract
The addition of graphitic fibers and flakes as fillers is commonly used to control the thermal expansion of metals. Sintered metal matrix composites with a planar distribution of graphite flakes show a low or negative thermal expansion coefficient perpendicular to the orientation plane of the graphite (z-CTE). Since the metal matrix has a positive isotropic expansion and graphite has a high z-CTE, this effect cannot be explained by a simple model of stapled metal–graphite layers. Instead, a mechanical interaction between graphite and matrix must be considered. With neutron scattering measurements, we show that there is little or no strain of the graphite flakes caused by the matrix, which can be explained by the high modulus of graphite. Instead, we suggest that a macroscopic crumpling of the flakes is responsible for the low z-CTE of the composite. The crumpled flakes are thicker at low temperature and get stretched and flattened by the expanding matrix at high temperature, explaining the reduction in the thermal expansion across the orientation plane.
en
dc.format.extent
13 S. (Manuskriptversion)
dc.rights.uri
http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen
dc.subject
thermal expansion
en
dc.subject
powder metallurgy
en
dc.subject
park plasma sintering
en
dc.subject.ddc
500 Natural sciences and mathematics::530 Physics::539 Modern physics
dc.title
Understanding the negative thermal expansion in planar graphite–metal composites
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1007/s10853-018-2879-y
dcterms.bibliographicCitation.journaltitle
Journal of Materials Science
dcterms.bibliographicCitation.number
2
dcterms.bibliographicCitation.pagestart
1267
dcterms.bibliographicCitation.pageend
1274
dcterms.bibliographicCitation.volume
54
dcterms.bibliographicCitation.url
http://link.springer.com/10.1007/s10853-018-2879-y
dcterms.rightsHolder.note
Copyright des Verlages
dcterms.rightsHolder.url
https://www.springer.com/gp/open-access/authors-rights/self-archiving-policy/2124
refubium.affiliation
Physics
refubium.affiliation.other
Institut für Experimentalphysik
refubium.note.author
Bei der PDF-Datei handelt es sich um eine Manuskriptversion des Artikels.
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.issn
0022-2461 (Print)
dcterms.isPartOf.issn
1573-4803 (Online)