Effect of Second Phase Particles on Solid Particles Erosion of Air Plasma Sprayed Yttria Stabilized Zirconia

2021 ◽  
Vol 875 ◽  
pp. 302-314
Author(s):  
Noveed Ejaz ◽  
Liaqat Ali ◽  
Muhammad Mansoor
Keyword(s):  
Mechanical Response ◽  
Ceramic Materials ◽  
Solid Particles ◽  
Yttria Stabilized Zirconia ◽  
Second Phase ◽  
Air Plasma ◽  
Ambient Conditions ◽  
Stabilized Zirconia ◽  
Phase Component ◽  
Plasma Sprayed

Yttria stabilized zirconia (YSZ) based composite topcoats were prepared with three advanced ceramic materials as second phase component; CaZrO3, (La0.75Nd0.25)2Zr2O7 and Nd2Ce2O7. The solid particles erosion (SPE) testing of the air plasma sprayed composite topcoats was carried out at room temperature and 900 °C to study the effects of second phase on erosion behavior. The erodent was angular fused alumina of 40-45 mm size. The erosion mechanism was followed in all topcoats with cracking and fracturing of the plasma sprayed splats due to erodent particles impact and impingement, whereas micro-ploughing was observed after 900 °C SPE testing as an additional feature. The hardness and intrinsic properties of second phase component in the composite topcoats played a crucial role in improving the erosion rate (ER) at ambient as well as 900 °C. The Nd2Ce2O7/YSZ topcoat show lower ER due to combatively higher hardness of Nd2Ce2O7 and good interfacial bonding with YSZ. The overall lowering of ER at 900 °C as compared to that of at ambient conditions was ascribed to the anelastic mechanical response of the ceramic topcoats due to thermal cycling involved in the SPE testing at high temperature.

scholarly journals Electrode and Electrolyte Materials From Atomistic Simulations: Properties of LixFEPO4 Electrode and Zircon-Based Ionic Conductors

2021 ◽  
Vol 9 ◽  
Author(s):  
Piotr M. Kowalski ◽  
Zhengda He ◽  
Oskar Cheong
Keyword(s):  
Energy Storage ◽  
Ceramic Materials ◽  
Yttria Stabilized Zirconia ◽  
Miscibility Gap ◽  
Ambient Conditions ◽  
Ionic Conductors ◽  
Stabilized Zirconia ◽  
Energy Storage Devices ◽  
Energy Applications ◽  
Pyrochlore Type

LixFePO4 orthophosphates and fluorite- and pyrochlore-type zirconate materials are widely considered as functional compounds in energy storage devices, either as electrode or solid state electrolyte. These ceramic materials show enhanced cation exchange and anion conductivity properties that makes them attractive for various energy applications. In this contribution we discuss thermodynamic properties of LixFePO4 and yttria-stabilized zirconia compounds, including formation enthalpies, stability, and solubility limits. We found that at ambient conditions LixFePO4 has a large miscibility gap, which is consistent with existing experimental evidence. We show that cubic zirconia becomes stabilized with Y content of ~8%, which is in line with experimental observations. The computed activation energy of 0.92eV and ionic conductivity for oxygen diffusion in yttria-stabilized zirconia are also in line with the measured data, which shows that atomistic modeling can be applied for accurate prediction of key materials properties. We discuss these results with the existing simulation-based data on these materials produced by our group over the last decade. Last, but not least, we discuss similarities of the considered compounds in considering them as materials for energy storage and radiation damage resistant matrices for immobilization of radionuclides.

scholarly journals Effects of Selective Laser Modification and Al Deposition on the Hot Corrosion Resistance of Ceria and Yttria-Stabilized Zirconia Thermal Barrier Coatings

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 353 ◽  
Author(s):  
Panpan Zhang ◽  
Xiaofeng Zhang ◽  
Fuhai Li ◽  
Zhihui Zhang ◽  
Hong Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Hot Corrosion ◽  
Molten Salts ◽  
Yttria Stabilized Zirconia ◽  
Air Plasma ◽  
Laser Remelting ◽  
Stabilized Zirconia ◽  
Α Al2o3 ◽  
Sprayed Coating ◽  
Plasma Sprayed

The air-plasma-sprayed ceria and yttria-stabilized zirconia (CYSZ) coating was modified by selective laser remelting and Al deposition to enhance hot corrosion resistance. The dotted coating was obtained after selective laser remelting. Magnetron sputtering was used to deposit an Al film on the dotted coating, and a vacuum heat treatment was subsequently performed to produce a dense α-Al2O3 overlay. Hot corrosion behavior of the following three types of coatings was investigated: plasma-sprayed, dotted, and dotted coatings combined with Al deposition (DA). Hot corrosion behaviors were evaluated in a mixture of 55 wt % V2O5 and 45 wt % Na2SO4 molten salts at 1000 °C for 30 h. The hot corrosion reaction between molten salts and zirconia stabilizers (Y2O3 and CeO2) led to the generation of monoclinic zirconia, YVO4, and CeVO4 plate-shaped crystals, and the mineralization of CeO2. The results indicated that the hot corrosion resistance of the DA coating was the best, and the dotted coating had superior hot corrosion resistance in comparison with the plasma-sprayed coating. The minimal surface roughness and dense dotted units improved the hot corrosion resistance of the dotted coating. The dense α-Al2O3 overlay with chemical inertness effectively inhibited the infiltration of molten salts, which led to the optimal hot corrosion resistance of the DA coating.

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