La2Zr2O7 thermal barrier coatings（TBCs） with dispersed Pt particles were prepared by cathode plasma electrolytic deposition（CPED） with ceramic balls added to the cathode region. Compared with the conventional CPED...La2Zr2O7 thermal barrier coatings（TBCs） with dispersed Pt particles were prepared by cathode plasma electrolytic deposition（CPED） with ceramic balls added to the cathode region. Compared with the conventional CPED, when ceramic balls are used in the cathode region, the plasma discharge ignition current density decreases approximately 62-fold and the stable plasma discharges occur at the whole cathode surface. Such TBCs with a thickness of 100 μm exhibit a crack-free surface and are composed of pyrochlore-structured La2Zr2O7. Cyclic oxidation, scratching, and thermal insulation capability tests show that such TBCs not only exhibit high resistance to oxidation and spallation but also provide good thermal insulation. These beneficial effects are attributed to the excellent properties of TBCs, such as good thermal insulation because of low thermal conductivity, high-temperature oxidation resistance because of low-oxygen diffusion rate, and good mechanical properties because of the toughening effect of Pt particles.展开更多
To increase the performance and efficiency of thermal barrier coating （TBC）, it is important to improve the thermal insulation property. In this work, a columnar AI film was deposited at the top of 7 wt% yttria- sta...To increase the performance and efficiency of thermal barrier coating （TBC）, it is important to improve the thermal insulation property. In this work, a columnar AI film was deposited at the top of 7 wt% yttria- stabilized zirconia （7YSZ） TBC by magnetron sputtering. A vacuum heat treatment was then carried out to improve the insulation property of Al-deposited TBC. Reaction mechanism of AI-ZrO2 system in AIdeposited TBC was studied by differential thermal analysis （DTA）. The phase structures of the assprayed TBC, the Al-deposited and vacuum-treated TBC were characterized. The microstructure evolution of M-deposited TBC was illustrated after vacuum heat treatment. And the insulation property of the assprayed TBC and treated TBC was compared. The results show that a multi-scaled layer, consisting of micron/ nano structured α-Al2O3 and AI3Zr grain was in situ synthesized at the top of 7YSZ coating via vacuum heat treatment. The TBC with the multi-scaled overlay has better insulation property than the asspraved TBC.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51271030)
文摘La2Zr2O7 thermal barrier coatings（TBCs） with dispersed Pt particles were prepared by cathode plasma electrolytic deposition（CPED） with ceramic balls added to the cathode region. Compared with the conventional CPED, when ceramic balls are used in the cathode region, the plasma discharge ignition current density decreases approximately 62-fold and the stable plasma discharges occur at the whole cathode surface. Such TBCs with a thickness of 100 μm exhibit a crack-free surface and are composed of pyrochlore-structured La2Zr2O7. Cyclic oxidation, scratching, and thermal insulation capability tests show that such TBCs not only exhibit high resistance to oxidation and spallation but also provide good thermal insulation. These beneficial effects are attributed to the excellent properties of TBCs, such as good thermal insulation because of low thermal conductivity, high-temperature oxidation resistance because of low-oxygen diffusion rate, and good mechanical properties because of the toughening effect of Pt particles.
基金supported by the National Basic Research Program of China ("973" program, No. 2012CB625100)the National Hightech Research and Development Program of China ("863" program, No. 2012AA03A512)
文摘To increase the performance and efficiency of thermal barrier coating （TBC）, it is important to improve the thermal insulation property. In this work, a columnar AI film was deposited at the top of 7 wt% yttria- stabilized zirconia （7YSZ） TBC by magnetron sputtering. A vacuum heat treatment was then carried out to improve the insulation property of Al-deposited TBC. Reaction mechanism of AI-ZrO2 system in AIdeposited TBC was studied by differential thermal analysis （DTA）. The phase structures of the assprayed TBC, the Al-deposited and vacuum-treated TBC were characterized. The microstructure evolution of M-deposited TBC was illustrated after vacuum heat treatment. And the insulation property of the assprayed TBC and treated TBC was compared. The results show that a multi-scaled layer, consisting of micron/ nano structured α-Al2O3 and AI3Zr grain was in situ synthesized at the top of 7YSZ coating via vacuum heat treatment. The TBC with the multi-scaled overlay has better insulation property than the asspraved TBC.
