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1328 |
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Monday, June 02, 2008, Auditorium 2 2:20 PM Solid Oxide Fuel Cell 1 Coatings for SOFC components for mobile and stationary applications, thermal and electrical insulation by thermal sprayed ceramic coatings |
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APS-triplex and LPPS-thin film as advanced plasma spraying technologies for industrialization of SOFC components |
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Malko Gindrat* / Sulzer Metco AG (Switzerland)
, Switzerland Arno Refke / Sulzer Metco AG (Switzerland), Switzerland Rajiv Damani/ Sulzer Innotec, Switzerland |
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The production of high quality coatings for SOFC applications in an industrial scale requires a stable, reliable and economically efficient process. Sulzer Metco proposes several solutions using different processes to fulfill the requirements of SOFC coating production. For example Diffusion Barrier Coatings (DBC) using perovskite material, such as LaSrMnO (LSM), is a ?state-of-the-art? production on metallic interconnects (IC) using the Triplex technology. The preferred plasma torch in this case is the newly developed TriplexPro?-200 which is a DC gun made of 3 cathodes and segmented cascaded anode producing a very stable plasma jet and having a long lifetime performance. This is a beneficial feature for high quality and reliable coatings in a mass production of SOFC functional layers. On the other hand, LPPS-Thin Film is the technology of choice for the production of very dense and thin (20-40 micrometer) electrolyte layers made of Yttria Stabilized Zirconia (YSZ) on various substrates. The high enthalpy plasma jet expanding at high velocity in a low pressure environment produces a plasma plume of 1-2 m length with a diameter of about 20-40 cm. These features allow covering homogeneously a 20 micrometer ceramic layer on a 300x150 mm surface at high deposition rate. Moreover, the reduced heat load on the substrate due to the larger surface energy distribution allows the deposition of dense ceramic layers on thin substrates without producing any deformation which is a crucial feature for advanced cell stack components. Despite the initial investment costs, LPPS-Thin Film appears to be a promising technology when high quantity production with economical advantages is required. Moreover, recent benchmarks between APS and LPPS-TF LSM coatings used for Cr-diffusion barrier on metallic IC substrates show that LPPS-Thin Film not only produces denser and thinner coatings but also becomes again competitive when considering the manufacturing of DBCs for metallic ICs on a high production scale. This paper presents the current developments of LPPS-Thin Film and APS-Triplex technologies in the domain of SOFC where high quality coatings produced in mass production are expected. The performance of the LPPS-Thin Film technology in comparison with the APS process using the TriplexPro?-200 will be described in the case of LSM coating properties on metallic substrates. Moreover, a detailed characterization of YSZ electrolyte coating on SOFC components, in particular for metal supported cells (MSC), will show the advantage of the LPPS-Thin Film technology for this type of coatings. |