Low porosity Yttrium oxide film by thermal spray

In this study, the commercial Y2O3 powder with particle size of 2~20 μm was grinded to size of 0.2~2 μm by ball mill process. The Y2O3 film was deposited on the 6061 aluminium alloy (AA6061) surface by thermal spray. The Y2O3 thermal spray film has microstructure with thickness of 200 μm, surface roughness of Ra 2 μm, local holes inside the Y2O3 film, and the porosity is about 7~10%. In order to reduce the porosity (2%) of Y2O3 thermal film the deposition rate of the Y2O3 film was decreased during thermal spray. Due to the lower film porosity, subsequent aerosol deposition can further be used to fill the pores, which can reduce the porosity of the film surface to less than 0.5%.