Wear resistance of chromium oxide nanostructured coatings

Nanostructured plasma-sprayed chromium oxide ceramic coatings, with a higher wear resistance than coatings obtained using micrometric powder as starting material have been developed. The influence of the starting powder, i.e. Cr2O3 fused crushed powders and Cr2O3 nanopowders having grains size of 100 nm, has been investigated. The nanopowders are reconstituted into spherical micrometer sized granules by the spray-drying process before plasma spraying. It is shown that due to their specific microstructure the wear resistance of the nanostructured coatings is more than 20 times higher compared to the coatings obtained using micrometric powder.