Nanomechanical properties of plasma-sprayed nanostructured and conventional 8YSZ thermal barrier coatings

Nanostructured thermal barrier coatings (TBCs) have become a noteble research field for the development of high-performance thermal protection coatings. The mechanical properties are essential for TBCs, which deter-mine the functionality, reliability and durability of coatings. In this article, the nanostructured 8YSZ (n-8YSZ) and conventional 8YSZ (c-8YSZ) coatings were fabricated by atmospheric plasma spraying (APS). The goal of the work is to do an evaluation and comparison of the nanomechanical properties of n-8YSZ and c-8YSZ coatings. The microstructure of coatings was observed by scanning electron microscopy and the nanomechanical prop-erties was characterized using nano-indenter. Results indicate that the microstructure of the n-8YSZ coating exhibits bi-modal distribution while the microstructure of the c-8YSZ coating shows mono-modal distribution. The elastic indentation work (We) is 11.952 +/- 1.243 nJ and the plastic indentation work (Wp) is 20.266 +/- 5.594 nJ for the n-8YSZ coating. Meanwhile, the We is 11.753 +/- 0.634 nJ and the Wp is 16.508 +/- 3.000 nJ for the c-8YSZ coating. The microstructure of the coating has little effect on We, but much on Wp. The dissipation ratio of plastic deformation work (eta) is 0.621 +/- 0.046 for the n-8YSZ coating and 0.579 +/- 0.042 for the c-8YSZ coating. Therefore, it can be predicted that the n-8YSZ coating is superior to the c-8YSZ coating in terms of erosion performance.

Automated summary

This article evaluates and compares the nanomechanical properties of nanostructured and conventional thermal barrier coatings (TBCs). The results show that the microstructure of the coating has a significant effect on the plastic indentation work, with the nanostructured coating exhibiting higher erosion performance.