Influence of Impurities on the Microstructure and Thermal Shock Resistance of YSZ Coatings

Abstract:

The impact of impurities on the microstructure and thermal shock resistance of YSZ TBCs was investigated. ZrO₂-7.5wt%Y₂O₃ (7.5YSZ) coatings of 5 spices of compositions (4 of them were doped with one type of impurity, namely, Al₂O₃, Fe₂O₃, SiO₂ and TiO₂, and the other was not doped) were manufactured by APS. Thermal shock tests of these TBCs were carried out at 1100 °C, and the samples were quenched in cold water in the temperature range from 20 to 25°C. The microstructure evolution and phase analysis were performed before and after the thermal shock tests by scanning electron microscope (SEM) and X-ray diffractometer (XRD). The results showed that the thermal shock lifetime of YSZ TBCs doped with impurities was obviously reduced compared to that of no-impurity TBCs. Additionally, the differences in the microstructure and phases of YSZ TBCs were ascertained and the elements distribution was tested by Energy Dispersive Spectrometer (EDS) and Energy Dispersive X-Ray Spectroscopy (EDX).

• Periodical: Materials Science Forum (Volume 898)
• Pages: 1414-1423
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.898.1414
• Online since: June 2017
• Authors: Yu Dao Wei*, Yue Guang Yu, Xiao Juan Ji, Hao Ran Peng
• Keywords: Impurities, Microstructure, TBCs, Thermal Shock Resistance, YSZ Coatings

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