Dependency of Anatase/Rutile Transformation to Thermal Spray Processes in TiO2 Nanostructure Coatings

TiO2 nanostructure coatings were deposited using three different thermal spray techniques namely flame, plasma and high velocity oxy-fuel (HVOF) spray. X-ray diffraction analysis was used to study the deposited TiO2 coating. It was concluded that a high anatase content of 80 vol. % can be achieved for the coating deposited by HVOF if Kerosene is used as fuel. On the contrary, the anatase content in the coating deposited by the flame and plasma spray processes were reduced to 29 vol. % and 5 vol. %,respectively due to their structural transformation of anatase to rutile. It was found that the structural transformation of anatase to rutile is significantly influenced by the thermal spray processes. Liquid-fueled HVOF technique can prevent this transformation.

Keywords:

TiO2 , Thermal spray , Phase transformation , Nanostructure coatings