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MM: Fachverband Metall- und Materialphysik

MM 12: Nanostructured Materials IV

MM 12.5: Vortrag

Montag, 25. Februar 2008, 17:45–18:00, H 0107

Initial stages of mechanical alloying of Fe-Cu-powders investigated by Atom Probe Tomography (APT) — •Catharina Wille¹, Malte Schmidt¹, Taláat Al-Kassab¹, Pyuck-Pa Choi², and Reiner Kirchheim¹ — ¹Georg-August-Universität Göttingen, Institut für Materialphysik, Göttingen, Germany — ²Korea Institute of Science and Technology, Nano-Materials Research Center, Seoul, Korea

Mechanically alloyed powders have been commonly used in industrial application (e.g. spray coatings) for several decades due to their outstanding macroscopic properties. Nevertheless the alloying mechanisms in immiscible systems, characterized by a positive heat of mixing, have not been fully understood so far. To elucidate these associated mechanisms a combination of Atom Probe Tomography (APT), Transmission-Electron-Microscopy (TEM) and X-Ray-Diffractometry (XRD) has been employed to the Fe-Cu-system, which serves as a binary model system.

Powders with low concentrations of the respective minority component ranging from 2.5 at.% to 10 at.% have been investigated, both for Fe-rich and Cu-rich materials. Among the studied milling times of 30min to 50h, this talk will put special emphasis on the shorter times, enabling to gain further insight into the early stages of alloying. Additionally, the effects of impurities such as Oxygen and Carbon on the alloying process will be presented and discussed.

Financial support from the Deutsche Forschungsgesellschaft under contract KI-230/33-1 is gratefully acknowledged.