Microstructure characteristics of EB-PVD YSZ thermal barrier coatings corroded by molten volcanic ash
Microstructure characteristics of EB-PVD YSZ thermal barrier coatings corroded by molten volcanic ash
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DOI：
10.1016/j.surfcoat.2015.12.003
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发表时间：
2016-01
影响因子：
5.4
通讯作者：
Cai Canying;C. Sheng;Yichun Zhou;Yang Li;Guangwen Zhou;Yanguo Wang
中科院分区：
文献类型：
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作者：
Cai Canying;C. Sheng;Yichun Zhou;Yang Li;Guangwen Zhou;Yanguo Wang
在1150 °C下，用天然火山灰（VA）对生长在多晶氧化铝（Al 2 O3）基体上的Y2 O3稳定的ZrO 2（YSZ）热障涂层（TBC）进行腐蚀。利用扫描电镜（SEM）、X射线衍射（XRD）、拉曼光谱、能谱（EDS）和透射电镜（TEM）研究了VA腐蚀引起的YSZ涂层、VA/YSZ和YSZ/Al 2 O3界面的微观组织和成分变化。结果表明，经VA腐蚀后的YSZ涂层晶粒长大，沿沉积方向沿着连接良好。结果表明，VA熔融沉积物贯穿整个YSZ层并完全填充YSZ层中的柱间间隙，导致在VA/YSZ界面附近的柱间间隙中析出晶态ZrSiO 4，在YSZ/Al 2 O3界面处析出钙长石（CaAl 2Si 2 O 8），并形成微裂纹。与钙长石沉淀相关联的生长应力被认为是引发YSZ/Al 2 O3界面区域TBCs降解的驱动力。
Y2O3-stabilized ZrO2(YSZ) thermal barrier coatings (TBCs) grown on a polycrystalline alumina (Al2O3) substrate are corroded by a natural volcanic ash (VA) at 1150 °C. The VA corrosion-induced microstructure development and composition evolution across the YSZ coating layer and at the VA/YSZ and YSZ/Al2O3interfaces are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). It is found that the VA-corroded YSZ coating undergoes grain growth and becomes well-connected along the deposition direction. It is shown that VA-molten depositions penetrate through the entire YSZ layer and fully fill the intercolumnar gaps in the YSZ layer, which results in crystalline ZrSiO4precipitates between the intercolumnar gaps near the VA/YSZ interface and anorthite (CaAl2Si2O8) precipitates at the YSZ/Al2O3interface with the micro-crack formation. The growth stresses associated with the anorthite precipitation is suggested as the driving force to initiate the degradation of TBCs at the YSZ/Al2O3interface region.