Abstract
Functional characteristics of materials including the mechanical, electrical, environmental and tribological performance can be significantly improved using nanostructured feedstock. Over the last few years much research has been dedicated to the development of thermal spraying techniques with liquid precursors to prepare fine nanostructured coatings. In this work nanostructured ceramic coatings were prepared using the technique of suspension spraying. Titania and alumina powders with sizes in the nanometre to submicrometre range were used to prepare aqueous and alcoholic suspensions. Atmospheric plasma and high-velocity flame were employed as enthalpy sources. The morphologies and crystalline structures of the sprayed ceramics were mainly characterised by SEM and XRD. The aim of this work was to carry out a comparative study and to discuss the nanostructured ceramic coating microstructures as a function of the physicochemical properties of the feedstock suspensions and spraying parameters.