Abstract
Materials with fine-scale structures are recognized to exhibit technologically efficient mechanical or thermal properties. Thermal sprayed nanostructured media could also be interesting in the optical field thanks to the diffusion interaction between short wavelength radiations and submicron-sized pores. One difficulty of the Suspension Plasma Spray (SPS) technique is to provide a sufficiently thick coating and to maintain efficient mechanical properties when the coating is removed from the substrate. The aim of this study was to spray a reflective and diffusive self-supporting alumina bilayer. The first coating was obtained by Atmospheric Plasma Spraying of micron-sized powders in order to obtain a thick layer and the second coating was sprayed by SPS onto the first one with strong adhesion. An oxide ceramic material with high scattering reflectance in a large band of wavelengths was thus obtained.
