Study On Ceramic Coating Blade

Blade is one of the most important parts of the coater blade and it influence the quality ofthe coated paper greatly. The traditional blade is blue planished steel and is easily to beoutworn. The ceramic coating blade is the blade which is being sprayed metal oxide usingthermal spraying and then accurate grinded. It has a good wear-resistance and a long termoperating life according to the traditional blade. We can not make coating blade domestic andcompletely rely on import while it has a heavy price.In this article, the ceramic coating blade is be made on the surface of the traditional bladesuccessfully using plasma spraying Al₂O₃—13%TiO₂ coating. The process variable of theplasma spraying is be researched by orthogonal analysis. A regression polynomial is workedout. Coating microstructures were assessed using scanning electron microscopy (SEM), X-raydiffraction (XRD) and transmission electron microscopy (TEM). Adhesive strength, hardnessand the wear-resistance of coatings were tested. The result is showing as followed:(1) It is feasible to spray ceramic coating on the surface of the steel blade ourselves.(2) Under the condition that the spraying voltage is 60 volt, and using porosity of thecoating and the flatness of the blade as evaluation criterion, the three spraying parameters asthe spraying current, the velocity of the spraying, the spraying distance are researched byorthogonal design. The parameters of plasma spraying Al₂O₃—13%TiO₂ is optimized asfollowed: the spraying current 500A, the spraying velocity 40m/min, the spraying distance80mm,and the spraying current 500A, the spraying velocity 40m/min, the sprayingdistance120mm.(3) A regression analysis is made using the orthogonal data and a regression polynomialis worked out. The variance test shows that the regression polynomial is highly credible.(4) The Al₂O₃ in both the import and the home-made ceramic coating are in thesemi-stable state ofγ-Al₂O₃ together with the stable state of a-Al₂O₃, the TiO₂ remains thestructure of rutile.