| Summary: | 碩士 === 逢甲大學 === 材料科學所 === 92 === Zirconia ceramic exhibits excellent fracture toughness, high ion conductivity, low electron conductivity, and low thermal conductivity properties. Therefore, YSZ films have been widely applied to be the solid electrolyte of fuel cell, oxygen sensor, wear protective coatings and the thermal barrier coatings of high temperature power-generator components.
Cathodic arc plasma ion plating (CAP) process is a promising coating technology which has high deposition rate, high atomic ionization and excellent film adhesion. In this study, the CAP process with Zr84Y16 cathode was used to deposit the YSZ film onto the Ni-base superalloy substrate. Substrate bias, working pressure and substrate to cathode distance were changed to reveal their effect on film microstructure.
The results show that the major phases of YSZ films were (111) oriented cubic and tetragonal structure. The crystallinity of the films increased with the enhancing negative substrate bias voltage which cause intensified ion bombardment on the film surface and facilitate the migration of adatoms to form crystalline of films. All films deposited in this study exhibits dense columnar structure. At lower substrate bias voltage, the surface morphology of YSZ films is rougher and consists of lots of facet protrusions. The macrodroplets would become flatter and the film surface would be smoother while the substrate bias voltage was increased. The film growth rates are 19 �慆/h and 18 �慆/h at the working distances 12 cm and 18 cm, respectively. The film composition is 2.15~2.99 at% Y, 17.22~18.76 at% Zr and 78.73~79.83 at% O. And the adhesion strength between YSZ film and substrate is poor because of the high internal stress in YSZ films and many microparticles coexisting in the films.
Campared with other deposition processes, Cathodic arc plasma ion plating process can be used to prepare high crystallinity and dense YSZ films. The growth rate of CAP-YSZ films is higher than sputter deposition process in ten-fold demonstrating the successful deposit ion of YSZ films using CAP process could be a useful method for preparation of solid electrolyte, thermal barrier coatings and the like.
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