Microstructure and mechanical properties of 8YSZ ceramics by liquid-phase sintering with CuO-TiO2 addition

Zhou, Hongming; Guo, Ya-Fang; Li, Jian; Yi, Danqing; Xiao, Lairong

doi:10.1007/s11771-012-1128-9

Cited by 17 publications

(5 citation statements)

References 23 publications

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“…Such grain growth may be attributed to liquid-phase sintering behavior, which is usually reported in CCTO ceramics. 10,11,14,33,36,38 The low-temperature eutectic liquid phase for CuO-TiO 2 occurs at approximately 919°C, 10,39 and the low melting point of LiF (~846°C) 40 is likely the primary source of the liquid phase during sintering. During the sintering process, charges diffuse more easily across the liquid phase than in the solid phase, giving rise to fast grain growth in the (Li + , F − ) co-doped CCTO ceramics.…”

Section: Resultsmentioning

confidence: 99%

Giant dielectric behavior of monovalent cation/anion (Li⁺, F⁻) co‐doped CaCu₃Ti₄O₁₂ ceramics

et al. 2019

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Giant dielectric behavior and electrical properties of monovalent cation/anion (Li+, F−) co‐doped CaCu3Ti4O12 ceramics prepared by a solid‐state reaction route were systematically investigated. Substitution of Li+ and F− led to a significantly enlarged mean grain size. A reduced loss tangent (tanδ ~0.06) with the retainment of an ultra‐high dielectric permittivity (ε′ ~7.7‐8.8 × 104) was achieved in the co‐doped ceramics, while the breakdown electric field and nonlinear coefficient of CaCu3Ti4O12 ceramics were increased by co‐doping with (Li+, F−). The variations in nonlinear electrical properties and giant dielectric response, as well as the dielectric relaxation, were well explained by the Maxwell‐Wagner polarization model for an electrically heterogeneous microstructure, in which a Schottky barrier height at the grain boundaries (GBs) was formed. ε′ was closely correlated to the GB capacitance. Significantly decreased tanδ value and enhanced nonlinear properties were related to a significant increase in the GB resistance, which was attributed to the significantly increased potential barrier height and conduction activation energy at the GBs. The semiconducting nature of the grains was also studied using X‐ray photoelectron spectroscopy and found to originate from the presence of Cu+ and Ti3+ ions.

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Section: Resultsmentioning

confidence: 99%

Giant dielectric behavior of monovalent cation/anion (Li⁺, F⁻) co‐doped CaCu₃Ti₄O₁₂ ceramics

et al. 2019

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“…Obviously, the hardness decreases almost linearly with the doping of the second phase. The hardness decreased from 10.6 GPa to 4.5GPa, which was higher than that of 8YSZ without additives (from 1.52 to 2.05 GPa) and was considerably lower than that of 8YSZ with additives CuO-TiO2 (17.2 to 17.96 GPa) [22] .…”

Section: Hardness and Fracture Toughnessmentioning

confidence: 65%

Mechanical Properties and Toughening Mechanisms of a Promising Zr-Y-Ta-O Composite Ceramics

Pi¹,

Fu²,

Zhang³

et al. 2023

Preprint

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ZrO2-YO1.5-TaO2.5(ZYTO) composite ceramic is considered to be the candidate of next generation of thermal barrier coatings as its excellent thermal stability and low thermal conductivity in high temperature, however, the mechanical properties and fracture tougheness of ZYTO system may be the shortcomings compared with the 8YSZ. In this study, ZYTO composite ceramics were successfully prepared by chemical coprecipitation reaction, the microsture of resulting composites were studied as a function of doping of M-YTaO4. Mechanical properties, including the density, porosity, hardness and Young's modulus, are determinate; the toughening mechanism were verified by the crack growth behavior of Vickers indentation test Results suggested that M-YTaO4 refines the fluorite phase grain and strengthens the grain interface in the composite ceramic. The thermal mismatch between the second phase and matrix produces residual stress in the bulk and affects the crack propagation behavior. With the increase of M-YTaO4 doping, the grain coarsening and ferroelastic domains are observed in the experiments. The ferroelastic domains with orthogonal polarization directions near crack tip evidences the ferroelastic toughening mechanism. The competition among these crack behaviors, such as cracks deflection, bridging and bifurcation, dominates the actual fracture toughness of the composite. The best toughening formula is determinate in the two-phase region and the highest fracture toughness is about to 3.1MPa·m1/2. Above all, mechanical properties of ZYTO composite ceramics look potential for thermal barrier coatings materials.

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“…Obviously, the hardness decreased almost linearly with the d of the second phase. The hardness decreased from 10.6 GPa to 4.5 GPa, which was than that of 8YSZ without additives (from 1.52 to 2.05 GPa) and was considerably than that of 8YSZ with additives CuO-TiO2 (17.2 to 17.96 GPa) [30].…”

Section: Hardness and Fracture Toughnessmentioning

confidence: 67%

Mechanical Properties and Toughening Mechanisms of Promising Zr-Y-Ta-O Composite Ceramics

Zhang

Zhu

et al. 2023

Coatings

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ZrO2-YO1.5-TaO2.5 (ZYTO) composite ceramics are considered to be a candidate for next-generation thermal barrier coatings (TBCs) due to their excellent thermal stability and low thermal conductivity in high temperatures; however, the mechanical properties and fracture toughness of the ZYTO system may be shortcomings compared with 7-8YSZ: the traditional TBC. In this study, ZYTO composite ceramics were successfully prepared by chemical coprecipitation reaction, and the microstructure of resulting composites was studied as a function of the doping of M-YTaO4. Mechanical properties, including the density, porosity, hardness and Young’s modulus, were all determinate; the toughening mechanism was verified by the crack growth behavior of the Vickers indentation test. The results suggest that M-YTaO4 refined the fluorite phase grain and strengthened the grain interface in the composite ceramic. The thermal mismatch between the second phase and matrix produced residual stress in the bulk and affected the crack propagation behavior. With the increase in M-YTaO4 doping, the grain coarsening and ferroelastic domains were observed in the experiments. The ferroelastic domains with orthogonal polarization directions near the crack tip evidenced the ferroelastic toughening mechanism. The competition among these crack behaviors, such as crack deflection, bridging and bifurcation, dominated the actual fracture toughness of the composite. The best toughening formula was determined in the two-phase region, and the highest indentation fracture toughness was about 42 J/m2, which was very close to 7-8YSZ’s 45 ± 5 J/m2.

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Microstructure and mechanical properties of 8YSZ ceramics by liquid-phase sintering with CuO-TiO2 addition

Cited by 17 publications

References 23 publications

Giant dielectric behavior of monovalent cation/anion (Li⁺, F⁻) co‐doped CaCu₃Ti₄O₁₂ ceramics

Giant dielectric behavior of monovalent cation/anion (Li⁺, F⁻) co‐doped CaCu₃Ti₄O₁₂ ceramics

Mechanical Properties and Toughening Mechanisms of a Promising Zr-Y-Ta-O Composite Ceramics

Mechanical Properties and Toughening Mechanisms of Promising Zr-Y-Ta-O Composite Ceramics

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Microstructure and mechanical properties of 8YSZ ceramics by liquid-phase sintering with CuO-TiO2 addition

Cited by 17 publications

References 23 publications

Giant dielectric behavior of monovalent cation/anion (Li+, F−) co‐doped CaCu3Ti4O12 ceramics

Giant dielectric behavior of monovalent cation/anion (Li+, F−) co‐doped CaCu3Ti4O12 ceramics

Mechanical Properties and Toughening Mechanisms of a Promising Zr-Y-Ta-O Composite Ceramics

Mechanical Properties and Toughening Mechanisms of Promising Zr-Y-Ta-O Composite Ceramics

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Giant dielectric behavior of monovalent cation/anion (Li⁺, F⁻) co‐doped CaCu₃Ti₄O₁₂ ceramics

Giant dielectric behavior of monovalent cation/anion (Li⁺, F⁻) co‐doped CaCu₃Ti₄O₁₂ ceramics