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MM: Fachverband Metall- und Materialphysik
MM 12: Nanostructured Materials IV
MM 12.5: Talk
Monday, February 25, 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.