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| Abstract No.: |
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Scheduled at:
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Monday, May 03, 2010, Moor Room 2:40 PM
Power Engineering and SOFC 1
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| Title: |
Technical challenges of suspension plasma spraying of nanopowders for SOFCs
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| Authors: |
Dennis Soysal* / German Aerospace Center (DLR - Deutsches Zentrum für Luft- und Raumfahrt), Germany
Asif Ansar / German Aerospace Center (DLR), Germany
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| Abstract: |
In Suspension plasma spraying (SPS) submicronic or nanosized powders are injected into the plasma using a liquid as a carrier. As in TriplexPro 200 only radial injection is possible, the need to control the injection meticulously becomes critical for an optimized penetration of the particles in the plasma jet. Different techniques are, therefore, developed and are presented in this paper. Coating microstructure and their characteristics are then discussed. A shadowgraphy system characterizes the penetration of suspension into the plasma and the Schieren optic system shows the density fluctuations around the plasma caused by the evaporation of the liquid carrier. A TEKNA enthalpy probe system is used to determine the influence of this liquid on the enthalpy field distribution of the plasma. Furthermore Suspension Plasma Spraying (SPS) for SOFC applications is presented as a valuable tool to improve fuel cell performance. Development and progress to produce nanostructured functional layers for solid oxide fuel cells by suspension plasma spraying is presented. The metallographic cross sections and SEM images of fractured coatings show the differences in microstructure to conventional coating techniques. Using SPS, highly porous coatings with an enhanced specific surface area were successfully produced which can be used for electrodes. The deposition efficiency of deposit as a function of injection parameters showed that the momentum of the droplets at injection can have a significant influence. The spray conditons were thus adapted in relation to the coating properties are set.
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