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dc.contributor.authorWille, Catharina Gabriele
dc.contributor.authorAl-Kassab, Talaát
dc.contributor.authorKirchheim, Reiner
dc.date.accessioned2015-08-03T09:04:11Z
dc.date.available2015-08-03T09:04:11Z
dc.date.issued2011-05
dc.identifier.issn03043991
dc.identifier.doi10.1016/j.ultramic.2011.01.036
dc.identifier.urihttp://hdl.handle.net/10754/561769
dc.description.abstractBeing widely accessible as well as already utilised in many applications, Fe-Cu acts as an ideal binary model alloy to elaborate the enforced nonequilibrium enhanced solubility in such a solution system that shows a limited regime of miscibility and characterised by a large positive heat of mixing. In addition to the detailed analysis of ball milled Fe-Cu powders by means of Atom Probe Tomography (APT), site specific structural analysis has been performed in this study using Transmission Electron Microscopy (TEM).In this contribution results on powders with low Cu concentrations (2.5-10 at%) are presented. Combining a ductile element (Cu, fcc) and a brittle one (Fe, bcc), striking differences in morphology were expected and found on all length-scales, depending on the mixing ratio of the two elements. However, not only could the atomic mixing of Fe and Cu be evaluated, but also the distribution of impurities, mostly stemming from the fabrication procedure. The combination of APT and TEM enables a correlation between the structural evolution and the chemical mixing during the milling process. For the first time, a clear distinction can be drawn between the morphological evolution at the surface and in the interior of the powder particles. This became possible owing to the site specific sample preparation of TEM lamellae by Focussed Ion Beam (FIB). Surprisingly, the texture arising from the ball milling process can directly be related to the classical rolling texture of cold rolled Fe. In addition, full homogeneity can be achieved even on the nano-scale for this material as shown by APT, resulting in an extended miscibility region in comparison to the equilibrium phase diagram. Grain sizes were determined by means of XRD and TEM. The strain corrected XRD results are in very good agreement with the values derived by TEM, both confirming a truly nanocrystalline structure. © 2011 Elsevier B.V.
dc.description.sponsorshipFinancial support from the Deutsche Forschungsgemeinschaft for a bi-national German (University of Goettingen)/South Korean (University of Ulsan) cooperation under the contract KI-230/33-1 is gratefully acknowledged.
dc.publisherElsevier BV
dc.subjectAtom probe tomography (APT)
dc.subjectFe-Cu
dc.subjectMechanical alloying
dc.subjectNanocrystalline
dc.subjectPowders
dc.subjectTransmission electron microscopy (TEM)
dc.titleTime evolution of morphology in mechanically alloyed Fe-Cu
dc.typeArticle
dc.contributor.departmentMaterials Science and Engineering Program
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Division
dc.identifier.journalUltramicroscopy
dc.contributor.institutionInstitute for Materials Physics, Georg-August-University Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
kaust.personWille, Catharina Gabriele


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