High-speed oxide coating by laser chemical vapor deposition and their nano-structure

Oxide thick films, partially yttria-stabilized zirconia (YSZ) and titania (TiO₂), were prepared by laser chemical vapor deposition (LCVD). The assistance of laser tremendously increased the deposition rate for YSZ and TiO₂ films up to 660 and 2500 μm/h, respectively. The increase in the deposition rate was accompanied by plasma formation around the deposition zone, and the plasma was observed over critical values of laser power and substrate pre-heating temperature. A wide variety of morphologies of films from feather-like columnar to dense microstructures were obtained depending on deposition conditions. The columnar structure contained a large amount of nano-pores at columnar boundary and inside grains. These columnar structure and nano-pores were advantageous for applying YSZ films to thermal barrier coatings.