Thermophysical properties and cyclic lifetime of plasma sprayed SrAl12O19 for thermal barrier coating applications |
| |
Authors: | Xin Zhou Wenjia Song Jieyan Yuan Qingmei Gong Hao Zhang Xueqiang Cao Donald B Dingwell |
| |
Affiliation: | 1. State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, China;2. Department of Materials Science and Engineering, Beihang University, Beijing, China;3. State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, China
Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität (LMU) Münich, Munich, Germany;4. Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität (LMU) Münich, Munich, Germany |
| |
Abstract: | About 6-8 wt% yttria-stabilized zirconia (YSZ) is the industry standard material for thermal barrier coatings (TBC). However, it cannot meet the long-term requirements for advanced engines due to the phase transformation and sintering issues above 1200°C. In this study, we have developed a magnetoplumbite-type SrAl12O19 coating fabricated by atmospheric plasma spray, which shows potential capability to be operated above 1200°C. SrAl12O19 coating exhibits large concentrations of cracks and pores (~26% porosity) after 1000 hours heat treatment at 1300°C, while the total porosity of YSZ coatings progressively decreases from the initial value of ~18% to ~5%. Due to the contribution of porous microstructure, an ultralow thermal conductivity (~1.36 W m?1 K?1) can be maintained for SrAl12O19 coating even after 1000 hours aging at 1300°C, which is far lower than that of the YSZ coating (~1.98 W m?1 K?1). In thermal cyclic fatigue test, the SrAl12O19/YSZ double-ceramic-layer coating undertakes a thermal cycling lifetime of ~512 cycles, which is not only much longer than its single-layer counterpart (~163 cycles), but also superior to that of YSZ coating (~392 cycles). These preliminary results suggest that SrAl12O19 might be a promising alternative TBC material to YSZ for applications above 1200°C. |
| |
Keywords: | sintering resistance SrAl12O19 thermal barrier coatings thermal conductivity thermal cycling |
|
|