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Licensed Unlicensed Requires Authentication Published by De Gruyter May 23, 2013

3D Characterization of Thermal Fatigue Damage in Monofilament Reinforced Copper for Heat Sink Applications in Fusion Reactor Systems

3D-Charakterisierung von thermischer Ermüdungsschädigung in Monofilament verstärktem Kupfer zur Anwendung als Wärmeleiter in Kernfusionsreaktorsystemen
M. Schöbel, H.P. Degischer, A. Brendel, B. Harrer and M. Di Michiel
From the journal Practical Metallography

Abstract

Monofilament reinforced metals (MFRM) are developed as high temperature heat sink materials for fusion reactor applications. These composites combine the high thermal conductivity (TC) of a Cu matrix with low thermal expansion (CTE) of SiC or W filaments. The CTE mismatch between matrix and reinforcement lead to high micro stresses under operation conditions. Stress induced thermal fatigue damage such as interface delamination and fiber/matrix damage degrades the thermal properties of these composites. Different interface designs are developed for SiC as well as W filaments to improve bonding strength and increase the long term stability. Conventional as well as synchrotron tomography was applied on different MFRMs to characterize thermal fatigue damage and its propagation before, during and after thermal cycling.

Kurzfassung

Mit Monofilamenten verstärkte Metalle (MFRMs) werden als Werkstoffe für Hochtemperatur-Wärmeableitvorrichtungen zur Anwendung in Kernfusionsreaktorsystemen entwickelt. In diesen Verbundwerkstoffen sind die hohe Wärmeleitfähigkeit (TC) einer Cu-Matrix mit der niedrigen Wärmedehnung (CTE) von SiC- oder W-Monofilamenten kombiniert. Durch den CTE-Unterschied zwischen Matrix und Verstärkung kommt es unter Betriebsbedingungen zu hohen Mikrospannungen. Infolge der spannungsinduzierten thermischen Ermüdung, wie z.B. Delamination an den Grenzflächen und Faser/Matrix-Schäden, verschlechtert sich das Wärmeverhalten dieser Verbundmaterialien. Zur Verbesserung der Haftfestigkeit und Erhöhung der Langzeitstabilität werden verschiedene Grenzflächenkonstruktionen für SiC- sowie W-Monofilamente entwickelt. An verschiedenen MFRMs wurden die herkömmliche Röntgentomografie sowie die Synchrotrontomographie angewandt, um die thermische Ermüdungsschädigung und ihre Ausbreitung vor, während und nach der Temperaturwechselbeanspruchung zu charakterisieren.


Übersetzung: J. Fritsche

Michael Schöbel Education: 1997 TU Vienna, Austria, Study of Physics. Since 2006, Institute of Materials Science and Technology. Work experience: FEM simulations, low temperature experiments on super conductors, TEM on light metals, stress and texture analysis by X-ray diffraction, synchrotron diffraction and tomography at ESRF and BESSY, neutron diffraction at HZB and FRM2.


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Received: 2011-1-31
Accepted: 2012-1-31
Published Online: 2013-05-23
Published in Print: 2012-05-01

© 2012, Carl Hanser Verlag, München