Mechanical Properties of Titania-Doped Yttria Stabilized Zirconia (TiYSZ) for Use as Thermal Barrier Coating (TBC)

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
M. Kibsey ◽  
J. Romualdez ◽  
X. Huang ◽  
R. Kearsey ◽  
Q. Yang
Keyword(s):  
Fracture Toughness ◽  
Tetragonal Phase ◽  
Bulk Material ◽  
Microstructural Analysis ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Clear Trend ◽  
Barrier Coating ◽  
Tio2 Addition ◽  
Co Doped

Representative samples of yttria stabilized zirconia (7YSZ) co-doped with varying concentrations of TiO2 were fabricated using plasma spraying. Samples were sintered in order to minimize porosity and to simulate the bulk material properties. After sintering, porosity levels of less than 1.25% were achieved. Both as-sprayed and sintered samples with 5, 10 and 15 wt% TiO2 addition levels were microstructurally characterized using SEM, XRD and optical image analysis methods. Vickers hardness, Young’s modulus, and fracture toughness were measured using nano and macroindentation methods. Microstructural analysis revealed that sintering of the TiO2 doped samples was required to achieve a homogeneous composition distribution, with TiO2 predominantly residing in solid solution within the ZrO2 matrix. Sintering for 325 hs at 1200 °C resulted in sufficient diffusion of TiO2 into the 7YSZ. The addition of TiO2 stabilized more tetragonal phase as revealed by XRD measurement. Sintering also showed significant improvements in fracture toughness in all co-doped samples. Fracture toughness values calculated using load-independent equations provided a clear trend in fracture toughness improvement with TiO2 addition. Ferroelastic toughening of the tetragonal phase was believed to have played an effect. There was also a reduction in monoclinic phase content with TiO2 addition, which may have limited microcrack formation and consequently increased the fracture toughness. With the addition of 10 wt% TiO2, the fracture toughness was improved by over 50%; however, this improvement started to decline at 15 wt% TiO2 addition. Volumetric porosity measurements also revealed significant improvements in fracture toughness with respect to lowering the porosity content as observed in all sintered samples.

Mechanical Properties of Titania-Doped Yttria Stabilized Zirconia (TiYSZ) for Use as Thermal Barrier Coating (TBC)

2011 ◽  
Author(s):  
M. Kibsey ◽  
J. Romualdez ◽  
X. Huang ◽  
R. Kearsey ◽  
Q. Yang
Keyword(s):  
Fracture Toughness ◽  
Tetragonal Phase ◽  
Bulk Material ◽  
Microstructural Analysis ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Clear Trend ◽  
Barrier Coating ◽  
Tio2 Addition ◽  
Co Doped

Representative samples of Yttria Stabilized Zirconia (7YSZ) co-doped with varying concentrations of TiO2 were fabricated using plasma spraying. Samples were sintered in order to minimize porosity and to simulate the bulk material properties. After sintering, porosity levels of less than 1.25% were achieved. Both as-sprayed and sintered samples with 5, 10 and 15 wt% TiO2 addition levels were microstructurally characterized using SEM, XRD and optical image analysis methods. Vickers hardness, Young’s modulus, and fracture toughness were measured using nano and macroindentation methods. Microstructural analysis revealed that sintering of the TiO2 doped samples was required to achieve a homogeneous composition distribution, with TiO2 predominantly residing in solid solution within the ZrO2 matrix. Sintering for 325 hours at 1200°C resulted in sufficient diffusion of TiO2 into the 7YSZ. The addition of TiO2 stabilized more tetragonal phase as revealed by XRD measurement. Sintering also showed significant improvements in fracture toughness in all co-doped samples. Fracture toughness values calculated using load-independent equations provided a clear trend in fracture toughness improvement with TiO2 addition. Ferroelastic toughening of the tetragonal phase was believed to have played an effect. There was also a reduction in monoclinic phase content with TiO2 addition, which may have limited microcrack formation and consequently increased the fracture toughness. With the addition of 10 wt% TiO2, the fracture toughness was improved by over 50%; however, this improvement started to decline at 15 wt% TiO2 addition. Volumetric porosity measurements also revealed significant improvements in fracture toughness with respect to lowering the porosity content as observed in all sintered samples.

scholarly journals The Effects on Thermal Efficiency of Yttria-Stabilized Zirconia and Lanthanum Zirconate-based Thermal Barrier Coatings on Aluminum Heating Block for 3d Printer

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 792
Author(s):  
Hasan Demir
Keyword(s):  
Temperature Distribution ◽  
Heat Loss ◽  
Yttria Stabilized Zirconia ◽  
Thermal Barrier ◽  
Print Quality ◽  
Stabilized Zirconia ◽  
Coating Materials ◽  
Lanthanum Zirconate ◽  
Barrier Coating ◽  
Coating Method

Fused filament fabrication is an important additive manufacturing method, for which 3D printers are the most commonly used printing tools. In this method, there are many factors that affect the printing quality, chief among which is temperature. The fusion temperature of the material is created by an aluminum heating block in the extruder. Stability and a constant temperature for the aluminum heating block are inevitable requirements for print quality. This study aims to use the thermal barrier coating method to increase the thermal efficiency and stability of the aluminum heating block by reducing heat loss. Furthermore, it aims to perform steady-state thermal analysis using finite element analysis software. The analyses are carried out in stagnant air environment and at the printing temperature of acrylonitrile butadiene styrene material. In order to examine the effects of different coating materials, blocks coated with two different coating materials, as well as uncoated blocks, were used in the analyses. The coating made with yttria-stabilized zirconia and pyrochlore-type lanthanum zirconate materials, together with the NiCRAl bond layer, prevent temperature fluctuation by preventing heat loss. The effects of the coating method on average heat flux density, temperature distribution of blocks, and temperature distribution of the filament tube hole were investigated. Additionally, changes in flow velocity were determined by examining the effects of the thermal barrier coating method on temperature distribution. The average heat flux density in the coated blocks decreased by 10.258%. Throughout the investigation, the temperature distributions in the coated blocks became homogeneous. It was also observed that both coating materials produce the same effect. This article performs a steady-state thermal analysis of a conventional model and thermal-barrier-coated models to increase print quality by reducing heat loss from the aluminum heating block.

Highly efficient up-conversion green emission in Ho/Yb co-doped yttria-stabilized zirconia single crystals

2019 ◽  
Vol 209 ◽  
pp. 95-101 ◽  
Author(s):  
Xiaojun Tan ◽  
Shoulei Xu ◽  
Fenhong Liu ◽  
Xiangyu Wang ◽  
Bernard A. Goodman ◽  
...  
Keyword(s):  
Single Crystals ◽  
Green Emission ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Highly Efficient ◽  
Co Doped

scholarly journals Effect of Crack Bridging on the Toughening of Ceramic/Graphene Composites

2018 ◽  
Vol 57 (1) ◽  
pp. 54-62 ◽  
Author(s):  
S.V. Bobylev ◽  
A.G. Sheinerman
Keyword(s):  
Experimental Data ◽  
Fracture Toughness ◽  
Crack Growth ◽  
Crack Deflection ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Crack Bridging ◽  
The Matrix ◽  
Graphene Content ◽  
Graphene Platelets

Abstract A model is proposed describing the effect of crack bridging on the fracture toughness of ceramic/graphene composites. The dependences of the fracture toughness on the graphene content and the sizes of the graphene platelets are calculated in the exemplary case of yttria stabilized zirconia (YSZ)/graphene composites. The calculations predict that if crack bridging prevails over crack deflection during crack growth, the maximum toughening can be achieved in the case of long graphene platelets provided that the latter do not rupture and adhere well to the matrix. The model shows good correlation with the experimental data at low graphene concentrations.

Mechanical and Structural Properties of Ion Implanted Yttria Stabiizeed Zirconia Ceramics

1983 ◽  
Vol 24 ◽  
Author(s):  
J. K. Cochran ◽  
K. O. Legg ◽  
H. F. Solnick-Legg
Keyword(s):  
Fracture Toughness ◽  
Penetration Depth ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Mechanical And Structural Properties ◽  
Knoop Microhardness ◽  
Vicker’S Microhardness ◽  
Reflection Electron Diffraction ◽  
Indenter Penetration

ABSTRACTSingle crystal yttria stabilized zirconia was implanted with 100 keV Ca+, Al+, and O2+ ions at fluences of 1015 to 6 × 1016 ions/cm2; . Blistering was observed at doses of 3 × 1016; O2;+ cm−2; and 6 × 1016; Al+ cm−2; but none was evident with Ca+. Knoop microhardness with a shallow indenter penetration depth peaked at a dose of 1016; ions/cm−2; for both Al+ and O2;+ but Ca+ produced no effect on microhardness. Vicker's microhardness with a much greater indenter penetration depth was not changed detectably by implantation but fracture toughness measurements from the same Vicker's indentations exhibited 10–23% increases at the highest O2+ doses and 20–25% increases at high Al+ doses. Annealing the highest implant doses at 1200° reduced the fracture toughness to pre-implant levels. Reflection electron diffraction showed that the surface had not been made amorphous by the 6 × 1016; Al+ dose as a well crystallized diffraction pattern was obtained.

Environmental Effect on the Crack Behavior of Yttria-Stabilized Zirconia During Laser Drilling

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Hong Shen ◽  
Juan Jiang ◽  
Decai Feng ◽  
Chen Xing ◽  
Xiaofeng Zhao ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Phase Transformation ◽  
Environmental Effect ◽  
Monoclinic Phase ◽  
Oxygen Vacancies ◽  
High Stress ◽  
Laser Drilling ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Crack Behavior

The crack behaviors of yttrium-stabilized zirconia during laser drilling in air, vacuum, and water environments were investigated. Due to the high stress and low fracture toughness induced by tetragonal-monoclinic phase transformation, tremendous cracks occur during drilling in air. Contrastly, cracks were reduced in vacuum drilling since the phase transformation was suppressed due to the generation of oxygen vacancies. By protection of water, no cracks were observed due to low stress and maintained fracture toughness. The crack mechanisms in different drilling media were discussed.

Elemental, Thermal, and Structural Characterization of ZnO Doped 8 mol% Yttria-Stabilized Zirconia (8YSZ) Ceramics

2017 ◽  
Vol 888 ◽  
pp. 57-61 ◽  
Author(s):  
Johar Banjuraizah ◽  
Tinesha Selvaraj ◽  
Zainal Arifin Ahmad
Keyword(s):  
Structural Characterization ◽  
Tetragonal Phase ◽  
Monoclinic Phase ◽  
Ionic Conductivities ◽  
Secondary Phase ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Mixed Powder ◽  
Dominant Phase

8 mol% of Yttrium oxide doped Zirconia (8YSZ) is one of the most explored compositions which give high ionic conductivities and good power output at 1000 °C. Generally, dopant was added to improve the sinterability of 8YSZ ceramics. In this present study, granulated 8YSZ powders with multimodal size was mixed with ZnO (0,1,2,3 wt%) using mortar and pestle. The mixed powder was compacted and sintered at 1550°C for 2 hours. 2 distinct endothermic peaks were observed in DTA plot of all samples. However, samples contain high amount of ZnO had a broader endothermic peak which resulted from the melting of ZnO. Rietveld refinement results indicate that the tetragonal phase appeared as the dominant phase for all doped and undoped samples, while cubic and monoclinic phase as the secondary phase. The monoclinic phase decreased as the amount of ZnO increased.

scholarly journals Evaluation of Phase Transformation and Mechanical Properties of Metastable Yttria-Stabilized Zirconia by Nanoindentation

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1677 ◽  
Author(s):  
Ningning Song ◽  
Ziyuan Wang ◽  
Yan Xing ◽  
Mengfei Zhang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Young’S Modulus ◽  
Tetragonal Phase ◽  
Young's Modulus ◽  
Traditional Approach ◽  
Yttria Stabilized Zirconia ◽  
Phase Identification ◽  
Stabilized Zirconia ◽  
T Phase

Microscopical nonuniformity of mechanical properties caused by phase transformation is one of the main reasons for the failure of the materials in engineering applications. Accurate measurement of the mechanical properties of each phase is of virtual importance, in which the traditional approach like Vickers hardness cannot accomplish, due to the large testing range. In this study, nanoindentation is firstly used to analyze the mechanical properties of each phase and demonstrate the phase transformation in thermal barrier coatings during high-temperature aging. The distribution of T-prime metastable tetragonal phase, cubic and tetragonal phase is determined by mapping mode of nanoindentation and confirmed with X-ray diffraction and scanning electron microscope observation. The results show that during 1300 °C aging, the phase transition of metastable Yttria-Stabilized Zirconia induces the quick decrease of T′ phase content and an increase of T and C phases accordingly. It is found that there are some fluctuations in the mechanical properties of individual phase during annealing. The hardness and Young’s modulus of T′ increase at first 9 h, due to the precipitation of Y3+ lean T phase and then decrease to a constant value accompanied by the precipitation of Y3+ rich C phase. The relevant property of C phases also increases a little firstly and then decreases to a constant, due to the homogenization of Y3+ content, while the hardness and Young’s modulus of T phase remain unchanged. After aging of 24h the hardness of T′, C and T phases are 20.5 GPa, 21.3 GPa and 19.1 GPa, respectively. The Young’s modulus of T′, C and T phases are 274 GPa, 275 GPa and 265 GPa, respectively. Present work reveals the availability of nanoindentation method to demonstrate the phase transformation and measure mechanical properties of composites. It also provides an efficient application for single phase identification of ceramics.

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