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Preparation Methods for Examining the ωo-Phase Formation in a β-Solidifying TiAl Alloy via Atom Probe Tomography

  • M. Schachermayer , T. Klein , H. Clemens and S. Mayer
Published/Copyright: February 1, 2016
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Abstract

Examinations with the atom probe are an excellent way to analyze all phases of a material on an atomic level, thus enabling a better understanding of their formation. This study aims to provide an appropriate method for the preparation of atom probe specimens made of multiphase intermetallic titanium aluminide alloys. With the help of a focused ion beam system and transmission kikuchi diffraction, tips of defined phases and phase interfaces were prepared, as is shown by the example of the ωo-Ti4Al3Nb phase, which is precipitated from the βo phase. The chemical composition of the two phases was determined by subsequent atom probe measurements which allowed to draw conclusions about the phase formation.

Kurzfassung

Untersuchungen mit der Atomsonde bieten eine ausgezeichnete Möglichkeit, alle Phasen eines Werkstoffes auf atomarer Ebene zu analysieren und so ein größeres Verständnis für die Bildung dieser zu erhalten. Ziel dieser Arbeit war es, eine geeignete Methode zu finden, die sich für die Zielpräparation von Atomsondenproben aus mehrphasigen intermetallischen Titanaluminid-Legierungen eignet. Mit Hilfe eines fokussierten Ionenstrahl-Systems und Transmissionskikuchibeugung konnten gezielt Spitzen von definierten Phasen und Grenzflächen präpariert werden, was am Beispiel der Phase ωo-Ti4Al3Nb, welche aus der βo-Phase ausgeschieden wird, gezeigt wird. Durch die anschließenden Atomsondenmessungen wurde die chemische Zusammensetzung der beiden Phasen bestimmt und daraus ein Rückschluss auf die Phasenbildung gezogen.


Translation: Marc Lackas


References / Literatur

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Received: 2015-09-25
Accepted: 2015-10-09
Published Online: 2016-02-01
Published in Print: 2016-02-15

© 2016, Carl Hanser Verlag, München

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