scholarly journals Investigation of High-Temperature Normal Infrared Spectral Emissivity of ZrO2 Thermal Barrier Coating Artefacts by the Modified Integrated Blackbody Method

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 235
Author(s):  
Tong Zhang ◽  
Xuyao Song ◽  
Gongjin Qi ◽  
Baolin An ◽  
Wei Dong ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coating ◽  
Radiation Thermometry ◽  
Spectral Emissivity ◽  
Standard Uncertainty ◽  
Thermal Barrier ◽  
Normal Spectral Emissivity ◽  
Zro2 Coating ◽  
Barrier Coating ◽  
Relative Standard

Zirconium oxide (ZrO2) is widely used as the thermal barrier coating in turbines and engines. Accurate emissivity measurement of ZrO2 coating at high temperatures, especially above 1000 °C, plays a vital role in thermal modelling and radiation thermometry. However, it is an extremely challenging enterprise, and very few high temperature emissivity results with rigorously estimated uncertainties have been published to date. The key issue for accurately measuring the high temperature emissivity is maintaining a hot surface without reflection from the hot environment, and avoiding passive or active oxidation of material, which will modify the emissivity. In this paper, a novel modified integrated blackbody method is reported to measure the high temperature normal spectral emissivity of ZrO2 coating in the temperature range 1000 °C to 1200 °C and spectral range 8 μm to 14 μm. The results and the associated uncertainty of the measurement were estimated and a relative standard uncertainty better than 7% (k = 2) is achieved.

Results From the Phase II Test Using the High-Temperature Developing Unit (HTDU)

1988 ◽  
Vol 110 (2) ◽  
pp. 251-258 ◽  
Author(s):  
S. Aoki ◽  
K. Teshima ◽  
M. Arai ◽  
H. Yamao
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermal Barrier Coating ◽  
Phase Ii ◽  
Thermal Barrier ◽  
Test Results ◽  
High Pressure Turbine ◽  
Barrier Coating ◽  
Two Stages

Phase II of the high-temperature turbine test was performed using the High-Temperature Developing Unit (HTDU). This unit has the same two stages as the high-pressure turbine of the AGTJ-100A reheat system. The purpose of the Phase II test was to investigate the potential of candidate technologies that may be applied to the advanced engine, the AGTJ-100B. Cooling characteristics of several cooling schemes for the first stage blades, and the performance of thermal barrier coating employed on the first stage nozzles and blades, were investigated. This paper presents the Phase II test results.

Sintering Behavior of Plasma-Sprayed Sm2Zr2O7 Coating

2010 ◽  
Author(s):  
Jianhua Yu ◽  
Huayu Zhao ◽  
Shunyan Tao ◽  
Xiaming Zhou ◽  
Chuanxian Ding
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
High Temperature ◽  
Thermal Expansion Coefficient ◽  
Thermal Barrier Coating ◽  
Expansion Coefficient ◽  
Sintering Behavior ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Plasma Sprayed

Plasma-sprayed thermal barrier coating (TBC) systems are widely used in gas turbine blades to increase turbine entry temperature (TET) and better efficiency. Yttria stabilized zirconia (YSZ) has been the conventional thermal barrier coating material because of its low thermal conductivity, relative high thermal expansion coefficient and good corrosion resistance. However the YSZ coatings can hardly fulfill the harsh requirements in future for higher reliability and the lower thermal conductivity at higher temperatures. Among the interesting TBC candidates, materials with pyrochlore structure show promising thermo-physical properties for use at temperatures exceeding 1200 °C. Sm2Zr2O7 bulk material does not only have high temperature stability, sintering resistance but also lower thermal conductivity and higher thermal expansion coefficient. The sintering characteristics of ceramic thermal barrier coatings under high temperature conditions are complex phenomena. In this paper, samarium zirconate (Sm2Zr2O7, SZ) powder and coatings were prepared by solid state reaction and atmosphere plasma spraying process, respectively. The microstructure development of coatings derived from sintering after heat-treated at 1200–1500 °C for 50 h have been investigated. The microstructure was examined by scanning electron microscopy (SEM) and the grain growth was analyzed in this paper as well.

Lanthanum–Cerium Oxide as a Thermal Barrier-Coating Material for High-Temperature Applications

2003 ◽  
Vol 15 (17) ◽  
pp. 1438-1442 ◽  
Author(s):  
X. Cao ◽  
R. Vassen ◽  
W. Fischer ◽  
F. Tietz ◽  
W. Jungen ◽  
...  
Keyword(s):  
High Temperature ◽  
Cerium Oxide ◽  
Thermal Barrier Coating ◽  
Coating Material ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Temperature Applications
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