Finite element analysis of TGO thickness on stress distribution and evolution of 8YSZ thermal barrier coatings |
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Authors: | Zhuoda Li Runguo Zheng Xiaoping Lin Yongqiang Lian Kangshuai Jin |
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Affiliation: | 1. School of Materials Science and Engineering, Northeastern University, Shenyang, China;2. School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao, China |
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Abstract: | According to the experimental research results of the thermally grown oxide (TGO) layered growth during the pre-oxidation process of 8 wt.% yttria-stabilized zirconia thermal barrier coating (TBC), a two-dimensional sinusoidal TC/bonding coat (BC) curve interface model of the longitudinal section of TBCs based on finite element simulation was constructed; the thickness and composition of the TGO layer relative to the TC/BC curve interfacial stress distribution and its evolution during the thermal cycling process were studied. The results show that when the TGO layer uses α-Al2O3 as the main oxide (black TGO), the thicker the black TGO layer, the more uniform the stress distribution of the TC/BC interface. When the TGO layer is dominated by spinel-structured Co and Cr oxides (gray TGO), the stress “band” of the TC/BC interface is destroyed; it shows the alternating phenomenon of tensile stress zone and compressive stress zone, and after the rapid random growth of TGO, the concentrated tensile stress increased by a large jump. Affected by the thickness of the prefabricated black TGO layer, there is a limit peak in the thickness of the black TGO layer, the normal stress at the TC/BC boundary is minimized, and the magnitude of the stress change is also minimized. |
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Keywords: | finite element pre-oxidation stress TGO growth thermal barrier coatings |
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