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Analytical Electron Microscopy of W-Core β-SiC Fibers for Use in an SiC-Based Composite Material for Fusion Applications

Published online by Cambridge University Press:  06 August 2013

Tea Toplišek
Affiliation:
Jozef Stefan Institute, Department for Nanostructured Materials, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
Medeja Gec
Affiliation:
Jozef Stefan Institute, Department for Nanostructured Materials, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
Aljaž Iveković
Affiliation:
Jozef Stefan Institute, Department for Nanostructured Materials, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
Saša Novak
Affiliation:
Jozef Stefan Institute, Department for Nanostructured Materials, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
Spomenka Kobe
Affiliation:
Jozef Stefan Institute, Department for Nanostructured Materials, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
Goran Dražić*
Affiliation:
Jozef Stefan Institute, Department for Nanostructured Materials, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
*
*Corresponding author. E-mail: [email protected]
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Abstract

In this work, the interactions between tungsten (W) and silicon carbide (SiC) in SigmaTM SiC fibers at high temperatures were characterized using scanning and transmission electron microscopy. These fibers could have the potential for use in fusion-related applications owing to their high thermal conductivity compared with pure SiC-based fibers. The as-received fibers were composed of a 100-μm-thick shell of radially textured β-SiC grains and a 15-μm-thick tungsten core, composed of a few hundreds of nm-sized elongated tungsten grains. The interfaces between the tungsten and the SiC and the SiC and the outer coatings were sharp and smooth. After heat treatment at 1,600°C for 3 h in Ar, the tungsten core reacted with SiC to form a rough interface surface. Inside the core, W5Si3, W3Si, and W2C phases were detected using energy-dispersive X-ray spectroscopy and electron-diffraction techniques. The mechanical properties of the fibers deteriorate after the heat treatment.

Type
Research Article
Copyright
Copyright © Microscopy Society of America 2013 

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