Due to its low weight and excellent dimensional stability, carbon fibre-reinforced carbon (C/C) gains more and more importance as construction material for light-weight charging racks in industrial furnaces. However, for high-temperature applications above 1,000 °C, C/C has to be protected with a diffusion-inhibiting coating in order to avoid an undesired carburization of components which are in contact with the charging rack. In the present work, coatings were produced by means of atmospheric plasma spraying (APS) and powder flame spraying (PFS). The ceramic powders Al2O3, Al2O3/Cr2O3, Al2O3/TiO2 and yttria stabilized zirconia (YSZ) were used as coating materials, while molybdenum and silicon carbide served as adhesion-promoting intermediate layers. In order to reduce the residual stresses in the ceramic coatings, specimens with a defined segmented surface structure were compared with conventional closed coatings. Long-term high-temperature tests in several atmospheres were conducted on laboratory scale as well as in industrial practice.

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