Untersuchungen von Eigenschaften plasmagespritzter Oxidkeramiken auf metallischen Grundwerkstoffen

Properties of plasma sprayed oxides on metallic substrates: Metallic substrates were coated with Cr$_{2}$O$_{3}$, Al$_{2}$O$_{3}$, ZrO$_{2^-}$7%Y$_{2}$O'$_{3}$ by plasma spray technique. An aim of this work was the investigation of the bonding mechanism between substrate and coating . From the results achieved by several analyzing methods (SEM, SLAMS) it was concluded that mechanical bonding of the spray particles on rough metallic substrate surfaces was the dominant adhesion mechanism. In a second step the influence of substrate material and -temperature on residual stress condition in chromia coatings was investigated. As analyzing method X-ray diffraction was applied. Further the phase composition of oxides was determined in dependance of the different process variants applied APS ( = atmospheric plasma spraying), VPS (= vacuum plasma spraying) and IPS ( = inert gas plasma spraying). Post heat treatment of coated samples influenced the phase composition and produced chemical reactions at the coating/substrate interface