In this work, CeO 2 -G d2 O 3 co-stabilized ZrO 2 (CGZ) thermal barrier coatings are deposited by solution precursor plasma spraying and the microstructure, phase stability, thermophysical properties, and thermal cycling behaviors of the resulting coatings are investigated and discussed in comparison to conventional 8YSZ coatings.

Strontium zirconate is a candidate material for thermal barrier coatings due to its high melting point, good sintering resistance, and high TCE. One drawback, however, is a phase transition that occurs below 1200 °C , although rare-earth element doping offers a way to suppress it. In this study, SrZrO 3 doped with two rare earth oxides, ytterbia and gadolinia, is deposited by solution precursor plasma spraying and the layers obtained are evaluated before and after heat treatment. The coatings are characterized by two phases, SrZrO 3 and t-ZrO 2 , with interpass boundary structure, nano and microscale porosity, and through-thickness vertical cracks. XRD analysis after heat treatment at 1400 °C for 360 h shows that the two phases are very stable due to the doping of rare-earth elements, which is also shown to reduce thermal conductivity in the as-sprayed deposits by nearly 35%.

In this work, the plasma sprayed titania coatings were treated by H 2 SO 4 for 24h at room temperature to improve the biological properties. The bioactivity was measured by simulated body fluid soaking test, and the biocompatibility was evaluated by quantifying the grafted collagen amount and in vitro cell culture test. The results showed that titania coatings treated by 0.1M and 1M H 2 SO 4 can induce bone-like apatite formation after immersion in SBF for 28 days, while the titania coating treated by 0.01M H 2 SO 4 can not. H 2 SO 4 treatment can promote the grafting of collagen on titania coatings. The in vitro cell culture test confirmed that collagen improved the cellular adhesion and proliferation on titania surface. In conclusion, a certain concentration of H 2 SO 4 treatment is beneficial in improving the bioactivity and biocompatibility of plasma sprayed titania coatings.