An assessment of the homogeneity of nano-crystalline Fe–Cu powders as studied by means of APT

Handle URI:
http://hdl.handle.net/10754/575664
Title:
An assessment of the homogeneity of nano-crystalline Fe–Cu powders as studied by means of APT
Authors:
Wille, Catharina; Al-Kassab, Talaat; Choi, Pyuck-Pa; Kwon, Young-Soon; Kirchheim, Reiner
Abstract:
In this contribution the homogeneity of mechanically alloyed Fe-Cu powders for two different compositions (Fe-10 and Fe-2.5 at%Cu) has been systematically characterised by atom probe tomography. Since Fe-Cu exhibits the Invar effect, it is among the most attractive systems for technical application. Furthermore, this system is immiscible and characterised by a large positive heat of mixing. In combination with the widespread application and accessibility, this predestines Fe-Cu as a binary model alloy to elaborate the enforced nonequilibrium enhanced solubility for immiscible systems. Depending on the parameters composition and milling time, results on the extension of the solubility limit and on the homogeneity of the alloy are presented, discussed and compared to earlier works. Only for the alloy with lower Cu content and for the prolonged milling time of 50 h, chemical homogeneity of the sample as measured by the atom probe was fully reached on the nano-scale. For all other parameter combinations homogeneity could not be achieved, even for long milling times and for those samples that appear to be homogeneous via X-ray analysis. Moreover, impurities were determined, mostly stemming from the fabrication procedure. The arrangement and homogeneity of the most common impurity, oxygen, was evaluated from atom probe data for different samples. Thus, the local concentration, segregation effects and the distribution of impurities could be quantified on the nano-scale, depending on the different nominal compositions and processing parameters. Additionally, structural information could be gained employing transmission electron microscopy and diffraction measurements. (C) 2008 Elsevier B.V. All rights reserved.
KAUST Department:
Materials Science and Engineering Program
Publisher:
Elsevier BV
Journal:
Ultramicroscopy
Issue Date:
Apr-2009
DOI:
10.1016/j.ultramic.2008.10.004
Type:
Article
ISSN:
0304-3991
Appears in Collections:
Articles; Materials Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorWille, Catharinaen
dc.contributor.authorAl-Kassab, Talaaten
dc.contributor.authorChoi, Pyuck-Paen
dc.contributor.authorKwon, Young-Soonen
dc.contributor.authorKirchheim, Reineren
dc.date.accessioned2015-08-24T08:35:21Zen
dc.date.available2015-08-24T08:35:21Zen
dc.date.issued2009-04en
dc.identifier.issn0304-3991en
dc.identifier.doi10.1016/j.ultramic.2008.10.004en
dc.identifier.urihttp://hdl.handle.net/10754/575664en
dc.description.abstractIn this contribution the homogeneity of mechanically alloyed Fe-Cu powders for two different compositions (Fe-10 and Fe-2.5 at%Cu) has been systematically characterised by atom probe tomography. Since Fe-Cu exhibits the Invar effect, it is among the most attractive systems for technical application. Furthermore, this system is immiscible and characterised by a large positive heat of mixing. In combination with the widespread application and accessibility, this predestines Fe-Cu as a binary model alloy to elaborate the enforced nonequilibrium enhanced solubility for immiscible systems. Depending on the parameters composition and milling time, results on the extension of the solubility limit and on the homogeneity of the alloy are presented, discussed and compared to earlier works. Only for the alloy with lower Cu content and for the prolonged milling time of 50 h, chemical homogeneity of the sample as measured by the atom probe was fully reached on the nano-scale. For all other parameter combinations homogeneity could not be achieved, even for long milling times and for those samples that appear to be homogeneous via X-ray analysis. Moreover, impurities were determined, mostly stemming from the fabrication procedure. The arrangement and homogeneity of the most common impurity, oxygen, was evaluated from atom probe data for different samples. Thus, the local concentration, segregation effects and the distribution of impurities could be quantified on the nano-scale, depending on the different nominal compositions and processing parameters. Additionally, structural information could be gained employing transmission electron microscopy and diffraction measurements. (C) 2008 Elsevier B.V. All rights reserved.en
dc.publisherElsevier BVen
dc.titleAn assessment of the homogeneity of nano-crystalline Fe–Cu powders as studied by means of APTen
dc.typeArticleen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.identifier.journalUltramicroscopyen
dc.contributor.institutionUniv Gottingen, Inst Mat Phys, D-37077 Gottingen, Germanyen
dc.contributor.institutionKorea Inst Sci & Technol, Nanomat Res Ctr, Seoul, South Koreaen
dc.contributor.institutionUniv Ulsan, Res Ctr Machine Parts & Mat Proc, Ulsan 680749, South Koreaen
kaust.authorAl-Kassab, Talaaten
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