Preliminary studies of TiO2 nanopowder deposition onto metallic substrate by low pressure cold spraying

Abstract Ceramic coatings, e.g. TiO2, can be produced by various methods, such as flame spraying, plasma spraying, PVD, CVD, etc. According to the literature, cold spraying enables deposition of plastic materials and therefore is dedicated to metals and polymers. Ceramics are hard and brittle due to the complex crystalline structure. However, very recently it was shown that chosen ceramics can be deposited by cold spraying. In this work, various polymorphs of sol-gel TiO2 powders, e.g. amorphous, anatase and rutile, were used as a feedstock for the cold spray (CS) process. The preliminary study of coating formation indicated that the key parameter for the process seems to be temperature of working gas. However, coatings were deposited form all prepared powders. Selected parameters enabled deposition of titania coatings with the thickness about 100 μm. What is even more interesting, the increase in the temperature of working gas results in nanocrystallization of the amorphous powder into anatase coating.