What is it about?
The turbines are usually recovered by ceramic coatings to guarantee higher temperatures as well lower degradation through hostile environments. These primary systems are composed by yttria-stabilized zirconia (YSZ), but new researches have found that the presence of rare-earth oxides, like Ta2O5 / Nb2O5 can increase the efficiency of mechanical properties for coatings. The lack of knowledge in this system leads this study with niobia, because of high production of them in Brazil. Samples made of 16% mol of Y2O3 and Nb2O5 were done with zirconia, that composition was used because there are traces of tetragonal phase stabilization, which is related to the best properties of the TBC. SEM images were obtained and by using a ImageJ software were done a microstructural analysis. It was possible to reveal the format of the grains, which appear to be equiaxials, their size, to be around 3μm, and the phases presented were revealed after thermal attack.
Featured Image
Why is it important?
The shape, size and distribution of the grains are important parameters to control the porosity and final density of the ceramic sample. One way to evaluate the grains is through quantitative image analysis.
Perspectives
The grains are distributed equiaxialy and its circularity confirms it. This condition is great for TBC, because the mechanical properties are the same to xand y-axis. The X-ray diffraction peaks for the 16% equimolar weight of Y2O3 and Nb2O5 show that it is a perfect composition to stabilize the system according to tetragonal phase.
Doctor Danieli DAP Reis Reis
Federal University of São Paulo
Read the Original
This page is a summary of: Image characterization after SEM analysis for equimolar samples of Nb2O5-YTZP, January 2012, American Institute of Physics,
DOI: 10.1063/1.3703346.
You can read the full text:
Contributors
The following have contributed to this page
