Deposition of TiO2 Coatings: Comparison between High Velocity Suspension Flame Spraying (HVSFS), Atmospheric Plasma Spraying and HVOF-spraying

A TiO2 (anatase) nanopowder suspension was processed by High Velocity Suspension Flame Spraying (HVSFS). The resulting coatings were characterized and compared to conventional atmospheric plasma sprayed (APS) and HVOFsprayed ones. The HVSFS operating parameters can be adjusted in order to achieve dense coatings, with a fine (nearnanosized) structure and a homogeneous distribution of anatase and rutile: these coatings have lower pore interconnectivity and higher wear resistance than APS and HVOF ones. Alternatively, quite large unmelted agglomerates of anatase nanoparticles can be embedded in the coating, increasing the porosity and the anatase content for enhanced photocatalytic efficiency