@article{Lu2023, author = {Yan-Hong Lu and Lu Huang and Mei-Jun Liu and Guan-Jun Yang and Chang-Jiu Li}, title = {Heterogeneous layered structure in thermal barrier coatings by plasma spray-physical vapor deposition}, year = {2023}, journal = {Journal of Advanced Ceramics}, volume = {12}, number = {2}, pages = {386-398}, keywords = {fracture mechanism, plasma spray-physical vapor deposition (PS-PVD), transient temperature, in-situ deposit surface, heterogeneous layered structure}, url = {https://www.sciopen.com/article/10.26599/JAC.2023.9220692}, doi = {10.26599/JAC.2023.9220692}, abstract = {The unique columnar structure endows thermal barrier coatings (TBCs) prepared by plasma spray-physical vapor deposition (PS-PVD) with high thermal insulation and long lifetime. However, the coating delamination failure resulting from an intra-column fracture (within a column rather than between columns) is a bottleneck in the solid dust particle impact environment for aero-engine. To clarify the intra-column fracture mechanism, a basic layer deposition model is developed to explore a heterogeneous weak-to-strong layered structure formed by a local transient in-situ deposit temperature. During the PS-PVD, an in-situ deposit surface is continuously updated due to constantly being covered by vapor condensation, showing a transient temperature, which means that the in-situ deposit surface temperature rises sharply in short period of 0.2 s of depositing a thin layer during a single pass. Meanwhile, the increasing temperature of the in-situ deposit surface results in an experimentally observed heterogeneous weak-to-strong structure, showing a continuous transition from a porous weak structure at the bottom region to a dense strong structure at the top region. This structure easily makes the intra-column fracture at the porous weak region. The results shed light on improving TBC lifetime by restraining the intra-column fracture.} }