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| Effect of YSZ layer porosity on thermal shock life of GYYSZ/YSZ thermal barrier coatings |
| LIU Xinyu1，2，ZHOU Wuping1，ZHANG Baohong2,3，XIONG Ning2,3，DU Zhong2,3 |
| （1. Iron & Steel Research Institute, Beijing 100081,China; 2. Advanced Technology & Materials Co., Ltd., Bei‐
jing 100081,China;3.ATTL Advanced Materials Co.，Ltd.，Beijing 100094，China） |
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Abstract Thermal barrier coating is an effective thermal protection measure for aerospace titanium alloy parts. As
the increase of service temperature in aerospace, the traditional 6%-8% Y2O3 stabilized ZrO2 ( 8YSZ ) thermal barri‐
er coating materials could not meet the thermal insulation and service life requirements of aerospace structural ma‐
terials. It is necessary to develop a new thermal barrier coating with excellent thermal cycling performance at high‐
er temperature. Three different structures of TBCs: A, B, and C were prepared on TA15 by plasma spraying, and
the microstructure, microhardness and thermal insulation of the coatings were characterized. Through the thermal
shock test at 1 200 ℃, the influence of the YSZ porosity of the transition layer on its thermal shock life perfor‐
mance was studied, and the failure mechanism of the coating was discussed. The experimental results show that the
thermal insulation effect of coating A is 1.2 times that of coating B and 1.1 times that of coating C at 1 200 ℃ due
to the high porosity and the doping of Gd and Yb rare earth elements. The transition layer 8YSZ coating has porosi‐
ty. The increase of the thermal insulation rate will improve the overall thermal insulation effect of TBCs to a certain
extent. The thermal shock life of coating C at 1 200 °C is 1.8 times that of coating A and 2.7 times that of coating
B, respectively. The fracture toughness and tensile strength of high-porosity GYYSZ coatings are low, and the intro‐
duction of YSZ transition layers can significantly improve the overall mechanical properties of TBCs.The increase
in porosity of the transition layer 8YSZ will improve the overall thermal insulation effect of TBCs to a certain extent.The design of LP-YSZ in coating C enhances the strength and toughness at the interface, and the increase in
the porosity of the transition layer YSZ increases the ability of TBCs to resist deformation and delays the connec‐
tion of vertical and transverse cracks in the coating.
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Received: 10 March 2022
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2022, Vol. 32 
