Nanostructured thermal barrier coatings(TBCs) often provide high degradation resistance, as well as extended lifetime. However, the underlying mechanism has not been fully understood. In this study, the sintering char...Nanostructured thermal barrier coatings(TBCs) often provide high degradation resistance, as well as extended lifetime. However, the underlying mechanism has not been fully understood. In this study, the sintering characteristics of nanostructured yttria-stabilized zirconia(YSZ) coatings were investigated,and compared with those of the conventional YSZ coatings. Multiscale characterizations of the changes in microstructures and properties were performed. Results showed that the enhanced high-performance durability was mainly attributed to different sintering mechanisms of lamellar zones and nanozones.Sintering characteristics of the lamellar zones were similar to those of the conventional coatings. Stagesensitive healing of two-dimensional(2 D) pores dominated the sintering behavior of the lamellar zones.However, the differential densification rates between nanozones and lamellar zones of the nanostructured TBCs led to the formation of coarse voids. This counteractive effect, against healing of 2 D pores, was the main factor contributing to the retardation of the performance degradation of bimodal TBCs during thermal exposure. Based on the understanding of the performance-degradation resistance, an outlook towards TBCs with higher performances was presented.展开更多
基金supported financially by the National Natural Science Foundation of China (Nos. 51801148, 51671159)the China Postdoctoral Science Foundation (No. 2018M631151)+2 种基金the National Basic Research Program of China (No. 2013CB035701)the Fundamental Research Funds for the Central Universitiesthe National Program for Support of Top-notch Young Professionals
文摘Nanostructured thermal barrier coatings(TBCs) often provide high degradation resistance, as well as extended lifetime. However, the underlying mechanism has not been fully understood. In this study, the sintering characteristics of nanostructured yttria-stabilized zirconia(YSZ) coatings were investigated,and compared with those of the conventional YSZ coatings. Multiscale characterizations of the changes in microstructures and properties were performed. Results showed that the enhanced high-performance durability was mainly attributed to different sintering mechanisms of lamellar zones and nanozones.Sintering characteristics of the lamellar zones were similar to those of the conventional coatings. Stagesensitive healing of two-dimensional(2 D) pores dominated the sintering behavior of the lamellar zones.However, the differential densification rates between nanozones and lamellar zones of the nanostructured TBCs led to the formation of coarse voids. This counteractive effect, against healing of 2 D pores, was the main factor contributing to the retardation of the performance degradation of bimodal TBCs during thermal exposure. Based on the understanding of the performance-degradation resistance, an outlook towards TBCs with higher performances was presented.
