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MM: Fachverband Metall- und Materialphysik

MM 36: Nano structured materials IV

MM 36.5: Vortrag

Donnerstag, 29. März 2007, 15:45–16:00, H4

Mechanically alloyed nanocrystalline Fe-Cu-powders investigated by Atomprobe Tomography (APT) — •Catharina Wille¹, Taláat Al-Kassab¹, Pyuck-Pa Choi², and Reiner Kirchheim¹ — ¹Georg-August-Universität Göttingen, Institut für Materialphysik — ²Korea Institute of Science and Technology, Nano-Materials Research Center

Atom Probe Tomography (APT) has been applied systematically to characterize mechanically alloyed powders chemically and microstructurally. Such powders are interesting from a technical point of view owing to their outstanding macroscopic properties and their frequent application as feed stock for powder metallurgical processing routes. Fe-Cu serves in this study as a binary model system representative for immiscible systems, characterized by a positive heat of mixing. Powders with concentrations between 2.5 and 10at% Cu were prepared by high energy ball milling applying milling times between 2 and 50h. In addition to the APT, Field-Ion-Microscopy- (FIM) and X-Ray-Diffractometry (XRD) -investigations are performed as well. Thus detailed nanoscale information on the local concentration of the minority component, segregation effects and the distribution of impurities can be gained. In this contribution results on the extension of the solubility limits and on the homogeneity of the alloy - both in dependency on the composition and milling time - are presented, discussed and compared to earlier works. Financial support from the Deutsche Forschungsgesellschaft under contract KI-230/33-1 is gratefully acknowledged.