Journal articles: 'Yttrium stabilised zirconium'

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Osipov, V. V., V. I. Solomonov, V. V. Platonov, O. A. Snigireva, M. G. Ivanov, and V. V. Lisenkov. "Laser plume spectroscopy. 2. Graphite yttrium-stabilised and zirconium oxide targets." Quantum Electronics 35, no. 7 (July 31, 2005): 633–37. http://dx.doi.org/10.1070/qe2005v035n07abeh004087.

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Hösel, T., Claas Müller, and Holger Reinecke. "Analysis of Surface Reaction Mechanisms on Electrically Non-Conductive Zirconia, Occurring within the Spark Erosion Process Chain." Key Engineering Materials 504-506 (February 2012): 1171–76. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.1171.

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Electrically insulating high performance ceramics like zirconia are increasingly used for high technological applications due to their extraordinary properties. Meanwhile even the spark erosion process can be used to structure non-conductive ceramics by using an assisting electrode (AE). This conductive AE is placed on top of the work piece to enable the process. The electrical contact is sustained during the process by carbonic residua of cracked oil used as a dielectric. For an enhanced understanding of the removal mechanisms during the spark erosion process of such non-conductive ceramics, we analysed the surface of ceramic samples during the entire spark erosion process chain. In our investigation a zirconium oxide with yttrium oxide stabilisation was chosen. For this purpose X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis was performed. The XRD results showed that the zirconium oxide reacts under the presence of carbonic residua during processing into zirconium carbide. This material supports sustaining the conductivity additionally, as it is conductive itself. In a subsequent thermal cleaning step with oxide atmosphere (T = 750°C), remaining carbonic residua are oxidised and thus removed. The XRD measurements after cleaning showed that the zirconium carbide was no longer detectable. Instead a monoclinic zirconium phase was found. This shows that a reverse reaction of zirconium carbide into zirconium oxide took place. To prevent the formation of a non-stabilised monoclinic phase, the oven process was adapted to higher temperatures of 900°C with higher heating and active cooling rates of up to 10 K/s. This adjustment shows that the monoclinic phase can be supressed and the reverse reaction leads to a tetragonal zirconium oxide like the bulk material.

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WENDEL, H., H. HOLZSCHUH, H. SUHR, G. ERKER, S. DEHNICKE, and M. MENA. "THIN ZIRCONIUM DIOXIDE AND YTTRIUM OXIDE-STABILIZED ZIRCONIUM DIOXIDE FILMS PREPARED BY PLASMA-CVD." Modern Physics Letters B 04, no. 19 (October 20, 1990): 1215–25. http://dx.doi.org/10.1142/s0217984990001537.

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Thin zirconia (zirconium dioxide) films are deposited by PECVD using as precursors organometallic compounds, metal alkoxides, and metal β-diketonates. The properties of the films depend on the substrate temperature, power density and the nature and partial pressure of the precursor. Thin films of zirconia stabilized with yttria (yttrium oxide) are formed at relatively low deposition temperatures (500°C) using the β-diketones of zirconium and yttrium.

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Kumproa, Kanatip, Apinon Nuntiya, Qi Wu Zhang, and Fumio Saito. "Synthesis of 8 %mol Yttria-Stabilized Zirconia Powders by Mechanochemical Processing of ZrOCl₂.8H₂O and YCl₃.6H₂0 with Li₂CO₃." Advanced Materials Research 93-94 (January 2010): 344–49. http://dx.doi.org/10.4028/www.scientific.net/amr.93-94.344.

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Mechanochemical processing of zirconium oxychloride and yttrium chloride precursors with lithium carbonate has been used to synthesis ultrafine powders of yttria-stabilized zirconia. The purposes of this work are to synthesis 8% mol yttria-stabilized zirconia powder via a mechanochemical process and to study the effect of LiCl as an inert diluent on agglomerate size of ultrafine powders. 8% mol yttria-stabilized zirconia powder was prepared from zirconium oxychloride and 8 %mol yttrium chloride precursors with lithium carbonate by using planetary ball mill and heat treatment. Chemical reaction between reactant mixtures occurs during post-milling heat treatment at low temperature to form composite powder. The products of this reaction consist of ultrafine powders embedded within LiCl as soluble salt by-product. The ultrafine powder is then recovered by removing the salt through a washing procedure. The powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis. The results indicated that 8% mol yttria-stabilized zirconia crystal structure depends on post-milling heat treatment temperatures. The structure of yttria-stabilized zirconia is transformed to a tetragonal form at 400 oC and 500 oC. Furthermore, it tends to form a cubic structure at 600 oC. However, agglomerate size of ultrafine powders also depends on the concentration of lithium chloride as an inert diluent and the washing procedure. Primary particle size of ultrafine powders is 30 nm.

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Wang, Xin M., and Ping Xiao. "Solvothermal synthesis of zirconia and yttria-stabilized zirconia nanocrystalline particles." Journal of Materials Research 22, no. 1 (January 2007): 46–55. http://dx.doi.org/10.1557/jmr.2007.0012.

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A solvothermal method was used to prepare zirconia and yttria-stabilized zirconia (YSZ) particles using zirconium hydroxide and yttrium hydroxide particles as precursors and ethanol or isopropanol as reaction media. The particle properties were characterized with x-ray diffractometry, scanning electron microscopy, transmission electron microscopy, thermal analysis, laser particle-size analysis, nitrogen adsorption (Brunauer–Emmett–Teller method) and Zeta potential analysis. Cubic/tetragonal ZrO2 and YSZ nanocrystals with crystallite size around 5 nm were obtained. The effect of different hydroxide precursors, attrition milling of hydroxide precursors, solvothermal processing conditions, and mineralizer was investigated and discussed by referring to the crystallization process of zirconium hydroxides.

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Melikhova, Oksana, Jan Kuriplach, Jakub Čížek, Ivan Procházka, and Gerhard Brauer. "Structure and Positron Characteristics of Basic Open Volume Defects in Zirconia." Materials Science Forum 607 (November 2008): 125–27. http://dx.doi.org/10.4028/www.scientific.net/msf.607.125.

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In this contribution we report on the theoretical study of basic vacancy-like defects in cubic zirconia and yttria stabilized zirconia. In particular, we concentrate on oxygen vacancy, zirconium vacancy and oxygen vacancy – yttrium complex. Relaxed atomic configurations of studied defects are obtained by means of an ab initio pseudopotential method within the supercell approach. Positron characteristics, like positron lifetime and binding energy to defects, are calculated using self-consistent electron densities and potentials taken from ab initio calculations.

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Rodaev, Vyacheslav V., Svetlana S. Razlivalova, Alexander I. Tyurin, Andrey O. Zhigachev, and Yuri I. Golovin. "Microstructure and Phase Composition of Yttria-Stabilized Zirconia Nanofibers Prepared by High-Temperature Calcination of Electrospun Zirconium Acetylacetonate/Yttrium Nitrate/Polyacrylonitrile Fibers." Fibers 7, no. 10 (September 25, 2019): 82. http://dx.doi.org/10.3390/fib7100082.

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For the first time, dense nanofibers of yttria-stabilized tetragonal zirconia with diameter of ca. 140 nm were prepared by calcination of electrospun zirconium acetylacetonate/yttrium nitrate/polyacrylonitrile fibers at 1100–1300 °C. Ceramic filaments were characterized by scanning electron microscopy, X-ray diffractometry, and nitrogen adsorption. With a rise in the calcination temperature from 1100 to 1300 °C, the fine-grain structure of the nanofibers transformed to coarse-grain ones with the grain size equal to the fiber diameter. It was revealed that fully tetragonal nanofibrous zirconia may be obtained at Y2O3 concentrations in the range of 2–3 mol% at all used calcination temperatures. The addition of 2–3 mol% yttria to zirconia inhibited ZrO2 grain growth, preventing nanofibers’ destruction at high calcination temperatures. Synthesized well-sintered, non-porous, yttria-stabilized tetragonal zirconia nanofibers can be considered as a promising material for composites’ reinforcement, including composites with ceramic matrix.

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Wewman, R. A. "Measurement of the Phase Composition of Partially Stabilized Zirconia (PSZ) Test Parts by X-Ray Powder Diffraction." Advances in X-ray Analysis 33 (1989): 467–74. http://dx.doi.org/10.1154/s0376030800019893.

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Zirconia(ZrO2) is one of a number of ceramic materials under development both at Dow and other companies for high cost, low-volume applications under severe corrosion/wear conditions. To improve the physical properties of zirconia, much work has been done worldwide in recent years developing partially stabilized zirconia, or PSZ. This is zirconium oxide which has been “stabilized” in the tetragonal form, typically by the addition of calcium or yttrium oxide. The term “partially stabilized” is given to these materials because the proper amount of oxide stabilizer will cause the zirconia to crystallize almost entirely in the tetragonal form under the proper processing conditions. However, the PSZ fabricated part is not completely stabilized, because it will undergo a tetragonal to monoclinic (T → M) phase transformation when subjected to an applied stress.

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Falcade, Tiago, Giselle Barbosa de Oliveira, Diego Pereira Tarragó, Vânia Caldas de Sousa, and Célia de Fraga Malfatti. "Influence of Substrate Temperature in the Morphology and Microstructure of YSZ Films Obtained on LSM Porous Substrate via Spray Pyrolysis." Materials Science Forum 727-728 (August 2012): 691–96. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.691.

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Many studies have been reported in the literature related to YSZ films deposited on dense substrate or applied directly on the SOFC anode. However, there are not a lot of studies about the YSZ deposition on the cathode. The present work aims to obtain yttria-stabilized zirconia (YSZ), using the spray pyrolysis technique, for their application as electrolyte in solid oxide fuel cells (SOFC). The films were obtained from a precursor solution containing zirconium and yttrium salts, dissolved in ethanol and propylene glycol (1:1), this solution was sprayed onto a heated LSM porous substrate. The substrate temperature was varied in order to obtain dense and homogeneous films. After deposition, the films were heat treated, aiming to crystallize and stabilize the zirconia cubic phase. The films were characterized by Scanning Electron Microscopy (SEM), thermal analysis, X-ray diffraction and Fourier transform Infrared Spectroscopy (FT-IR).

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Lazar, Dolores Ribeiro Ricci, Sandra Maria Cunha, Valter Ussui, E. Fancio, Nelson Batista de Lima, and Ana Helena A. Bressiani. "Influence of Synthesis Route on Phase Formation and Sinterability of Hydroxyapatite-Zirconia Composites." Materials Science Forum 591-593 (August 2008): 722–27. http://dx.doi.org/10.4028/www.scientific.net/msf.591-593.722.

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Reinforcement with yttria stabilized zirconia (YSZ) is an alternative to improve mechanical strength of hydroxyapatite (HAp) ceramic. However, calcium may react with zirconium to form calcium zirconate. In addition, decomposition of HAp to tricalcium phosphate (TCP) occurs with water loss inhibiting ceramic densification. In order to minimize the formation of these compounds, two synthesis routes were compared in this work: coprecipitation of hydrous yttria stabilized zirconia in a calcium phosphate gel medium and powder mixture of individual calcined powders. Composite nominal compositions were fixed at 90 and 95 HAp wt%. Calcium, zirconium and yttrium chlorides and ammonium hydrogen phosphate were the employed precursors. Ammonium hydroxide was the selected precipitation agent. Calcination was performed at 800oC for 1 hour and pellets were sintered in the range of 1150 and 1350oC for 1, 3 and 5 hours. Ceramic samples were characterized by scanning electron microscopy and apparent density measurements. Crystalline phases were quantified by Rietveld analysis of X-ray diffraction patterns. Results indicate that powders prepared by coprecipitation can cause porosity formation due to the higher chemical reactivity during synthesis process.

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Xin, Ying, Wei Hui Jiang, Guo Feng, Jian Min Liu, Quan Zhang, Qian Wu, and Li Feng Miao. "Low Temperature Synthesis of Yttrium-Stabilized Zirconia (YSZ) Fibers by Non-Hydrolytic Sol-Gel Method." Advanced Materials Research 1104 (May 2015): 101–6. http://dx.doi.org/10.4028/www.scientific.net/amr.1104.101.

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Yttrium-stabilized zirconia fibers were prepared at low temperature via a novel non-hydrolytic sol-gel (NHSG) method by using anhydrous zirconium chloride as precursor, ethanol as oxygen donor, yttrium hydride as stabilizer, dibasic ester (DBE) as solvent, ethoxyline as spinning aid. DTA-TG, XRD, FT-IR, FE-SEM and TEM were used to characterize samples. The results show that the YSZ tetragonal zirconia can be synthesized at 410 °C and the formation of =Y-O-Zr≡ bond is the key for the low temperature synthesis tetragonal zirconia. Zirconia fibers calcined at 800 °C have a smooth surface, free of crack and dense section. The diameter of fibers are in the range of 5~10 μm. The addition of ethoxyline can make the colloidal particles linear growth which is the basic reason for the spinnability of the sol.

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Falcade, Tiago, Diego Pereira Tarragó, Cibele Melo Halmenschlager, Vânia Caldas de Sousa, Claudia Trindade de Oliveira, and Célia Fraga Malfatti. "Elaboration of Yttria-Stabilized Zirconia Films on Porous Substrates." Materials Science Forum 660-661 (October 2010): 707–11. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.707.

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The development of solid oxide fuel cell has shown that the thin film concept for the electrode supported designs, based on the yttria-stabilized zirconia, is more promising than the research of new electrolyte materials. In this work, the spray pyrolysis process was investigated in order to obtain dense thin films of YSZ on porous ceramic substrates. High porosity LSM, a typical material of SOFC cathodes, was used as substrate. The precursor solution was obtained by zirconium and yttrium salts dissolved in a mixture of ethanol and propylene glycol, with volume ratio 1:1. The substrate was heated and maintained at a constant temperature (280°C, 340°C or 560°C). The as-obtained films were heat treated in a temperature of 700°C, aiming to obtain yttria-stabilized-zirconia films from the amorphous film. The morphology and microstructure of the films were characterized by scanning electron microscopy and X-ray diffraction.

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Smith, Roger M., Xiao-Dong Zhou, Wayne Huebner, and Harlan U. Anderson. "Novel yttrium-stabilized zirconia polymeric precursor for the fabrication of thin films." Journal of Materials Research 19, no. 9 (September 2004): 2708–13. http://dx.doi.org/10.1557/jmr.2004.0352.

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An acetate-based polymeric precursor for producing yttrium-stabilized zirconia (YSZ) was developed. The precursor was prepared under ambient conditions and contains only yttrium and zirconium cations. Dense, crack-free films were fabricated with this precursor on alumina substrates at a rate of 60 nm per deposition, producing polycrystalline YSZ at temperatures as low as 600 °C. Grain growth in thin YSZ films followed Arrhenius equation with an activation energy approximately 0.45 eV. The residual strain in YSZ films decreased with increasing annealing temperature from 600 to 900 °C.

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Агарков, Д. А., М. А. Борик, Г. М. Кораблева, А. В. Кулебякин, И. Е. Курицына, Е. Е. Ломонова, Ф. О. Милович, et al. "Влияние термообработки на теплопроводность монокристаллов твердых растворов на основе ZrO-=SUB=-2-=/SUB=-, стабилизированных оксидами скандия и иттрия." Физика твердого тела 62, no. 12 (2020): 2093. http://dx.doi.org/10.21883/ftt.2020.12.50213.160.

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The effect of heat treatment at 1000° C for 400 hours on the thermal conductivity of crystals stabilized with scandium oxide, (ZrO2)1-x(Sc2O3)x (x = 0.08–0.10), and together with scandium and yttrium oxides, (ZrO2)1-x-y(Sc2O3)x(Y2O3)y (x = 0.003−0.20; y = 0.02−0.025). For crystals of zirconium dioxide stabilized with scandium oxide, the most noticeable changes in thermal conductivity concern 9ScSZ crystals, in which changes in the phase composition occur, and a noticeable amount of rhombohedral phase appears. For 8ScSZ crystals, these changes are less noticeable and are mainly caused by the ordering of oxygen vacancies and changes in the microstructure of the samples, while for 10ScSZ crystals they are practically absent. The 10ScSZ crystals have the minimum electrical conductivity, both before and after annealing, which is determined by the highest content of scandium oxide in the solid solution. Small changes in thermal conductivity concern crystals of partially stabilized zirconia codoped with scandium and yttrium oxides. For cubic crystals 8Sc2YSZ and 10Sc2YSZ, there are practically no changes in the value of thermal conductivity, the nature of the temperature dependence of thermal conductivity, and the phase composition of crystals. The introduction of yttrium oxide into solid solutions based on zirconium dioxide along with scandium oxide makes it possible to increase the stability of its phase composition and structurally dependent thermal and electrophysical characteristics.

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Alpe´rine, S., and L. Lelait. "Microstructural Investigations of Plasma-Sprayed Yttria Partially Stabilized Zirconia TBC (In Relation to Thermomechanical Resistance and High-Temperature Oxidation Mechanisms)." Journal of Engineering for Gas Turbines and Power 116, no. 1 (January 1, 1994): 258–65. http://dx.doi.org/10.1115/1.2906802.

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This study deals with microstructural investigations of plasma-sprayed yttria partially stabilized zirconia thermal barrier coatings, performed by classical and analytical transmission electron microscopy. The aim of the study was to determine eventual relationships between coating microstructure and toughness. The ceramic/metal interface, which plays an important role during TBC thermomechanical solicitation, has also been studied. In the 6–8 wt. percent Y2O3 range, the metastable tetragonal t′ phase is observed, showing special faulted microstructural features, such as grain twinning and antiphase boundary planes. Moreover, after high-temperature annealing in air, a very fine and stable precipitation of the equilibrium cubic phase appears. It is believed that these microstructural elements could act as crack deviation sites and enhance the coatings’ intrinsic toughness. Microstructural investigations of the alumina scales grown during high-temperature annealing reveal yttrium segregation at oxide grain boundaries as well as significant quantities of zirconium inside the alumina grains. The oxide growth seems to be dominated by a classical grain boundary oxygen diffusion mechanism. The presence of zirconium inside the alumina grains suggests that Al2O3 also partially forms by chemical reduction of ZrO2 by Al.

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Yoshito, Walter Kenji, Valter Ussui, Dolores Ribeiro Ricci Lazar, and José Octavio A. Pascoal. "Synthesis and Characterization of NiO-8YSZ Powders by Coprecipitation Route." Materials Science Forum 498-499 (November 2005): 612–17. http://dx.doi.org/10.4028/www.scientific.net/msf.498-499.612.

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Nickel oxide – 8 mol% yttria stabilized zirconia (NiO-8YSZ) powders containing 25 to 75 wt% of NiO were prepared by coprecipitation. The entire process includes the reaction of metals aqueous chloride solutions (heated at 95 oC) with ammonium hydroxide, washing steps of the resulting gel, butanol azeotropic distillation treatment to prevent the formation of hard agglomerates, drying, calcination and ball milling. The yield of precipitation of metals was determined by inductively coupled plasma atomic emission spectroscopy analysis (ICP-AES). Powders were characterized by X-ray and laser diffraction, infrared analysis, gas adsorption (BET) and scanning electron microscopy. It was observed that zirconium and yttrium hydroxides are easily precipitated in alkaline medium, while nickel precipitation yield is in the range of 80 to 95% due to the formation of soluble complexes. NiO appears as a second phase in synthesized powders and contributes to decreasing of specific surface area and agglomerate mean size.

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Muñoz, R. A., J. E. Rodriguez, C. Santos, and Cosme Roberto Moreira Silva. "Quantitative Phases Determination of Zirconia Ceramics via Rietveld Method." Materials Science Forum 660-661 (October 2010): 989–94. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.989.

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Industrial applications of partially stabilized zirconia (PSZ) has increased substantially recently, considering its excellent thermal stability, strength and ionic conductibility. Its main application includes oxygen sensors and fuel cells. In this work zirconia ceramic powder is produced by Pechini process, mixing citric acid and ethylene glycol, adding yttrium and zirconium precursors. All the process was carried out with complete agitation. The obtained powder after this procedure is heat treated at 650°C during two hours. Characterization was performed by infra-red spectroscopy, x-ray diffractometry and quantitative analysis by Rietveld Method. The results show tetragonal and monoclinic phases, with nanometric crystallite.

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Qureshi, Imran Nazir, Muhammad Shahid, and A. Nusair Khan. "Effect of Na₂SO₄-V₂O₅ Mixture on Y₂O₃ Stabilized ZrO₂ Thermal Barrier Coatings Exposed at High Temperature." Advanced Materials Research 1101 (April 2015): 423–27. http://dx.doi.org/10.4028/www.scientific.net/amr.1101.423.

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Yttria stabilized zirconia thermal barrier coating (TBC) along with CoNiCrAlY bondcoat was deposited using air plasma spray on Inconel-X750 superalloy. The coated samples were exposed at 9500C in a mixture of Na2SO4and V2O5. The exposed specimens were investigated using XRD and SEM. The formation of spinel and perovskite structures was revealed at the interface of topcoat and the bondcoat. XRD analyses of the samples confirmed phase transformation of the tetragonal zirconia into monoclinic zirconia and yttrium vanadate.

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Ivanov, A. S., D. V. Martynov, Valentina Nikolaevna Olesova, R. S. Zaslavsky, K. V. Shmatov, A. I. Lerner, and D. I. Morozov. "ZIRCONIA AS A MODERN MATERIAL FOR DENTAL PROSTHESES AND IMPLANTS." Russian Journal of Dentistry 23, no. 1 (February 15, 2019): 4–6. http://dx.doi.org/10.18821/1728-2802-2019-23-1-4-6.

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On the example of dental implants the results of studying the strength of ceramics from zirconium dioxide stabilized by yttrium and titanium of one manufacturer under static and dynamic loads are presented. The microstructure of a ceramic implant made of zirconium dioxide stabilized by yttrium is described. The elemental composition of the implant ceramics is given, the compliance with the manufacturer’s formulation is confirmed. The developed textured surface of the ceramic implant is shown.

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Molodetsky, I., A. Navrotsky, F. DiSalvo, and M. Lerch. "Energetics of oxidation of oxynitrides: Zr–N–O, Y–Zr–N–O, Ca–Zr–N–O, and Mg–Zr–N–O." Journal of Materials Research 15, no. 11 (November 2000): 2558–70. http://dx.doi.org/10.1557/jmr.2000.0366.

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The enthalpies of oxidation, δHox, of oxynitrides YyZr1−yO2x−0.5y−2/3xNx (0.016 < x < 0.2), CayZr1−yO2x−y−2/3xNx (0.03 < x < 0.14), MgyZr1−yO2x−y−2/3xNx (0.146 < x < 0.28), and Zr–O–N (β-type and γ phases) are measured using drop solution calorimetry in molten sodium molybdate (3Na2O · 4MoO3) at 973 K. Linear relations between the enthalpy δHox and nitrogen content were found in all oxynitrides. They indicate that, within the experimental range of nitrogen concentrations, sites occupied by nitrogen ions are energetically equivalent in a given substitutional series. The enthalpies normalized per mole of nitrogen, δHnox, for compounds of Y–Zr–N–O, Ca–Zr–N–O, and Zr–N–O are similar, about −500 kJ/(mol of N). A more exothermic value of δHnox, of about −950 kJ/(mol of N), is seen in Mg–Zr–N–O compounds. The energetics of vacancy formation in zirconium oxynitrides was determined and compared to the energetics of vacancy formation in yttria- and calcia-stabilized zirconia. The enthalpy of vacancy formation (enthalpy of formation relative to end members normalized per vacancy) in zirconium oxynitrides (−190.5 ± 27.0 kJ/mol of Vö) is more exothermic than that in yttria- and calcia-stabilized zirconia (−105 ± 7.2 and −91.4 ± 3.8 kJ/mol of Vö, respectively). This is consistent with the higher tendency for long-range ordering in zirconium oxynitrides compared to stabilized zirconia. Some technological implications of the results are briefly discussed.

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Wang, Xiao Bei, Yuan Hua Lin, and Xu Liang Deng. "Preparation and Characterization of Functional Gradient Porous ZrO₂ Ceramics." Key Engineering Materials 519 (July 2012): 287–90. http://dx.doi.org/10.4028/www.scientific.net/kem.519.287.

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Porous zirconium dioxide (ZrO2) ceramics has been widely used in biomedicine, heat-insulation and piezoelectric actuators. In this study, a kind of porous ZrO2 ceramics with the gradient porosity and pore sizes was designed to be a composite lamellar material. The porosity and pore size change regularly through the thickness of the layers. This porous lamellar zirconic material has been prepared by the solid state reaction consisting of yttria-stabilized zirconia (YSZ) and stearic acid (SA) powders. The porosity and pore size can be tuned by the addition of SA. The mechanical properties of the graded porous ZrO2 have been studied in detail. The results show that the mechanical characteristics of the gradient porous ZrO2 can be controlled by changing the porosity and pore size.

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Tao, Liu Shi, Yu Feng Chen, Shi Chao Zhang, Ke Wei Deng, Hao Ran Sun, Xian Kai Sun, Da Chen Yan, Kai Fang, and Na Li. "Preparation and Performance of Zirconia Fiber Board." Solid State Phenomena 281 (August 2018): 912–17. http://dx.doi.org/10.4028/www.scientific.net/ssp.281.912.

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Zirconia fiber not only can be used for a long time in 1600°C, but also has low thermal conductivity at high temperature. Due to the excellent insulation performance, it has a broad application prospect in aerospace, aviation, energy and other areas. In the present study, we chose yttrium stabilized zirconia fibers and nanometer zirconia powder as main material and adding soluble starch, zirconium sol as low temperature and high temperature binder. Rigid zirconia fiber board was prepared by material slurry, filter shaping, stripping drying and high temperature calcination. After high temperature calcination of 1600°C for 12h, sample pore are mainly concentrated in 25-75μm, bending strength performance is best when the adding amount of nanometer zirconia powder was 7%, the thermal conductivity is only 0.132 W·m-1·K-1 at 1400°C.

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Nguyen, Alexander K., Peter L. Goering, John A. Olenick, Kathy Olenick, and Roger J. Narayan. "Sintered Tape-cast 3YSZ Supports Human Bone Marrow Derived Stem Cell Osteogenic Differentiation." MRS Advances 4, no. 46-47 (2019): 2541–49. http://dx.doi.org/10.1557/adv.2019.335.

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ABSTRACTSintered tape-cast yttria-stabilized zirconia (YSZ) was evaluated for its elemental composition, crystal structure, and imaged with atomic force microscopy (AFM) and scanning electron microscopy (SEM). Human bone marrow stem cells (hBMSC) were cultured on the ceramic and differentiated into the osteoblast lineage; alkaline phosphatase (ALP) activity was tracked as a differentiation marker. The YSZ was composed of purely tetragonal grains with a median equivalent circular diameter of 283 nm. Zirconium, yttrium, oxygen, and adventitious carbon was detected on the substrate with no other elements in significant quantities detected. YSZ samples had an RMS roughness value of 27 nm, elastic modulus of 206 ± 14 GPa, and hardness of 14 ± 2 GPa. hBMSC were observed to attach and proliferate on the YSZ surfaces and had significantly increased ALP versus the undifferentiated control cultured on glass. This method for producing a YSZ ceramic yields a typical material of this type and supports attachment and differentiation of hBMSC; thus, making it useful as a bone implant material.

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Amiriyan, Mahdi, Singh Ramesh, Iis Sopyan, Meenaloshini Satgunam, Ranna Tolouei, and Wan Dung Teng. "Pressureless Sintering of Electro-Conductive Zirconia Composites." Materials Science Forum 694 (July 2011): 304–8. http://dx.doi.org/10.4028/www.scientific.net/msf.694.304.

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In the present work, 3 mol% Yttria-stabilized tetragonal zirconia (Y-TZP) composite containing 25 wt.% of zirconium diboride (ZrB2) was prepared via pressureless sintering method in an inert atmosphere over the temperature range of 1350-1550°C for one hour. The effect of zirconium diboride content in the zirconia matrix, as well as the sintering temperature on densification, phase stability and electrical properties of sintered samples have been studied. The results revealed that there was a significant increased in electrical conductivity of sintered samples when 25 wt.% of ZrB2 is incorporated into Y-TZP matrix.

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Milani, R., R. P. Cardoso, T. Belmonte, C. A. Figueroa, C. A. Perottoni, J. E. Zorzi, G. V. Soares, and I. J. R. Baumvol. "Nitriding of yttria-stabilized zirconia in atmospheric pressure microwave plasma." Journal of Materials Research 24, no. 6 (June 2009): 2021–28. http://dx.doi.org/10.1557/jmr.2009.0245.

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High temperature plasma nitriding of yttria-partially-stabilized zirconia in atmospheric pressure microwave plasma was investigated. The morphological, mechanical, and physicochemical characteristics of the resulting nitrided layer were characterized by different methods, such as optical and scanning electron microscopy, microindentation, x-ray diffraction, narrow resonant nuclear reaction profiling, secondary neutral mass spectrometry, and x-ray photoelectron spectroscopy, aiming at investigating the applicability of this highly efficient process for nitriding of ceramics. The structure of the plasma nitrided layer was found to be complex, composed of tetragonal and cubic zirconia, as well as zirconium nitride and oxynitride. The growth rate of the nitrided layer, 4 µm/min, is much higher than that obtained by any other previous nitriding process, whereas a typical 50% increase in Vickers hardness over that of yttria-partially-stabilized zirconia was observed.

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Drajewicz, Marcin, Kamil Dychtoń, and Marek Góral. "Thermal Properties of YSZ Powders for Plasma Spraying." Solid State Phenomena 227 (January 2015): 413–16. http://dx.doi.org/10.4028/www.scientific.net/ssp.227.413.

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The oxides in the case of theirs properties are important materials for industrial application especially, in aircraft industry for application as thermal barrier coatings. Thermal properties of zirconium oxide stabilized by yttria are better than other ceramic materials. This powder could be stabilized in room temperature by addition of rare earth elements. In this article the thermal analyses of yttria stabilized zirconia (YSZ) oxide are presented as a baseline for future measurements of thermal properties of YSZ powder with addition of rare earth elements. The thermal expansion, specific heat, thermal diffusivity and thermal conductivity of commercially available Matco 6700 powder offered by Sulzer Metco company were analyzed by thermal methods.

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Karagedov, G. R., and E. G. Avvakumov. "Low-temperature synthesis of ZrO2-8 mol.% Y2O3 nanopowder with high sinterability." Science of Sintering 43, no. 3 (2011): 239–45. http://dx.doi.org/10.2298/sos1103239k.

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The possibility of low-temperature synthesis of yttrium-stabilized (8 mol.%) zirconium dioxide nanopowder from a mixture of hydrated zirconium oxynitrate and yttrium carbonate mechanically activated in a continuous-type mill is examined. It is demonstrated that the powder formed at as low temperature as 600?C and then subjected to a disaggregation procedure can be easily compacted by dry pressing and achieves nearly full density on sintering.

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Halmenschlager, Cibele Melo, Matias de Angelis Korb, Roberto Neagu, Carlos Pérez Bergmann, and Célia de Fraga Malfatti. "Nanostructured YSZ Thin Film for Application as Electrolyte in an Electrode Supported SOFC." Materials Science Forum 727-728 (August 2012): 873–78. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.873.

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The development of solid oxide fuel cell with thin film concepts for an electrode supported design based on the yttria-stabilized zirconia has demonstrated favourable results due to its high chemistry stability in oxidization and environment reduction. The spray pyrolysis process was investigated in order to obtain dense thin films of YSZ on different substrates. The precursor solution was obtained by zirconium and yttrium salt dissolutions in a mixture of water and glycerine in several ratios to study the solvent influence. The substrate was initially heated at 600 °C and during the deposition it ranged from 260-350°C, finishing at a fast increase in temperature of 600°C. The heat treatment was carried out in four different temperatures: 700 °C, 750 °C, 800 °C, and 900 °. The precursors were characterized by thermal analysis. The microstructures of the films were studied using scanning electron microscopy and X-ray diffraction. The results obtained showed that the films obtained were crystalline before the heat treatment process and have shown ionic conductivity above 800°C.

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29

Takigawa, Yorinobu, Yukihisa Naka, and Kenji Higashi. "Effect of Cation Dopant on Phase Stability of Zirconia Bioceramics in Hot Water." Advances in Science and Technology 49 (October 2006): 97–102. http://dx.doi.org/10.4028/www.scientific.net/ast.49.97.

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The effect of cation ion dopant on phase transformation of zirconia bioceramics is evaluated by ageing in hot water. The phase transformation progresses with time in all specimens. However, the transformation behavior is much different depending on the dopant. The transformation is promoted when the 1 mol% of pentavalent element is added to 3mol% yttria stabilized zirconia (3Y-TZP). In contrast, the transformation is suppressed when the bivalent element is added. In case that the tetravalent element is added, the transformation is promoted if the ionic radius of the element is larger than that of zirconium, and the transformation is suppressed if the element with smaller ionic radius than zirconium ion is added. This result indicates that the ionic radius and the valency of ions are important factors to control the phase stability in zirconia.

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30

Nguyen, Linh Ba Ngoc, Dung Van Hoang, and Van Thi Thanh Tran. "Investigating the effect of yttria contents on the structure and mechanical properties of zirconia ceramics." Science and Technology Development Journal 19, no. 4 (December 31, 2016): 232–40. http://dx.doi.org/10.32508/stdj.v19i4.685.

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In this study, the co- precipitation method and annealing process were used to prepare the yttria stabilized zirconia ceramics. Data of Raman and XRD showed that an increase of yttria doping leads to an decrease of the ratio between monoclinic and tetragonal phases. Howerver, it existed a critical concentration of yttrium at which the highest value of hardness was about 14.5 GPa and grain sizes of 0.2–0.5 m. An investigation of low temperature degradation indicated that theaging process only occurred in the first 5 hours and then virtually negligible changes.

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31

Pinto, M. A., W. R. Osório, C. R. P., A. García, and M. C. F. Ierardi. "Laser surface treatment of plasma-sprayed yttria-stabilized zirconia coatings." Revista de Metalurgia 41, Extra (December 17, 2005): 154–59. http://dx.doi.org/10.3989/revmetalm.2005.v41.iextra.1016.

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32

Stanovyi, O., S. Kutovyy, Yu Morozov, A. Naumenko, I. Dmitruk, and A. Borodyanska. "Low-Temperature Thermoluminescence Studies of the Nanocrystalline Yttria-Stabilized Zirconia." Ukrainian Journal of Physics 61, no. 6 (June 2016): 489–94. http://dx.doi.org/10.15407/ujpe61.06.0489.

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33

Rękas, M. "Electrolytes For Intermediate Temperature Solid Oxide Fuel Cells." Archives of Metallurgy and Materials 60, no. 2 (June 1, 2015): 891–96. http://dx.doi.org/10.1515/amm-2015-0225.

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Abstract Solid electrolytes for construction of the intermediate-temperature solid oxide fuel cells, IT-SOFC, have been reviewed. Yttrium stabilized tetragonal zirconia polycrystals, YTZP, as a potential electrolyte of IT-SOFC have been highlighted. The experimental results involving structural, microstructural, electrical properties based on our own studies were presented. In order to study aluminum diffusion in YTZP, aluminum oxide was deposited on the surface of 3 mol.% yttria stabilized tetragonal zirconia polycrystals (3Y-TZP). The samples were annealed at temperatures from 1523 to 1773 K. Diffusion profiles of Al in the form of mean concentration vs. depth in B-type kinetic region were investigated by secondary ion mass spectroscopy (SIMS). Both the lattice (DB) and grain boundary (DGB) diffusion were determined.

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34

PING, WANG, ZHOU LIGUO, HAN JING, and GUO YONGCHUN. "EFFECTS OF YTTRIUM NITRATE ON MICROSTRUCTURE AND HIGH TEMPERATURE RESISTANCE OF ZrO2–Y2O3 CERAMIC COATINGS PREPARED BY A MODIFIED PEO PROCESS ON AN Al–12Si ALLOY." Surface Review and Letters 24, Supp02 (November 2017): 1850026. http://dx.doi.org/10.1142/s0218625x18500269.

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A ZrO2–Al2O3 ceramic coating and YSZ–Al2O3 coating were prepared on ZAlSil2Cu3Ni2 alloys by a modified plasma electrolytic oxidation (PEO) in zirconium salt solution. The microstructure, heat-insulating and high temperature oxidation properties were investigated by SEM, XRD and a fabricated heat insulation temperature testing device. The results showed that the surface of the YSZ–Al2O3 coating was composed of fine particles and had lower roughness. Yttrium partially stabilized the zirconia solid solution (Y[Formula: see text]Zr[Formula: see text]O[Formula: see text] which was formed in zirconium yttrium salt solution with a higher reaction temperature. The growth rate of the YSZ–Al2O3 coating was greater than the ZrO2–Al2O3 coating. Especially, the outward growth obviously improves. Furthermore, the heat insulation property of the coating enhances. The curves of the weight gains in the sample with YSZ–Al2O3 coating showed a logarithmic shape under the high temperature oxidation treatment of 400[Formula: see text]C. The weight gains of the sample with YSZ–Al2O3 coating were relatively lower than that of the as-coated sample. The ceramic layer had good high temperature stability.

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35

Gomez-Garcia, Diego, Julian Martinez-Fernandez, Arturo Dominguez-Rodriguez, and Kenneth H. Westmacott. "Zirconium Nitride Precipitation in Nominally Pure Yttria-Stabilized Zirconia." Journal of the American Ceramic Society 79, no. 2 (February 1996): 487–90. http://dx.doi.org/10.1111/j.1151-2916.1996.tb08149.x.

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36

Ahmadi Pidani, Raheleh, Reza Shoja Razavi, Reza Mozafarinia, and Hossein Jamali. "Comparison of Hot Corrosion Resistance of YSZ and CYSZ Thermal Barrier Coatings in Presence of Sulfate-Vanadate Molten Salts." Advanced Materials Research 472-475 (February 2012): 141–44. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.141.

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In this study, NiCoCrAlY bond coat and two types of top coat including yttria stabilized zirconia (YSZ) and ceria and yttria stabilized zirconia (CYSZ) were deposited on IN 738LC by air plasma spraying (APS). Hot corrosion behavior of samples in 1000 °C was study using 55wt.%V2O5-45wt.%Na2SO4 corrosive salt. Characterization and analysis of results was done by employing field emission scanning electron microscope (FESEM) and x-ray diffractometry (XRD). Results ravealed that plasma sprayed CYSZ TBCs exhibited excellent hot corrosion resistance which was superior to that of YSZ TBCs due to strong acidity and high contents of stabilizer.

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37

Giuseppe, Gianfranco Di, and J. Robert Selman. "Anode-supported planar solid oxide fuel cells by plasma-enhanced metalorganic chemical vapor deposition (PE-MOCVD) and electrostatic spray deposition (ESD): Fabrication of dense thin layers of yttria-stabilized zirconia by PE-MOCVD." Journal of Materials Research 16, no. 10 (October 2001): 2983–91. http://dx.doi.org/10.1557/jmr.2001.0409.

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This paper reports a study of plasma-enhanced metalorganic chemical vapor deposition (PE-MOCVD) as a suitable technique for depositing dense, crack-free thin layers of yttria-stabilized zirconia onto porous substrates, as a step in the fabrication of anode-supported planar solid oxide fuel cells (SOFC). Our objective is to present an alternative method by which an SOFC assembly may be fabricated at lower temperature than by conventional methods. PE-MOCVD using zirconium tertbutoxide (ZrTB) -and yttrium hexafluoroacetylacetonate dihydrate (Y6FA) is capable of producing the electrolyte in thin dense layers on smooth surfaces, as demonstrated for Si(110) wafers. If a porous substrate is used, the average surface pore size should not exceed 1–2 μm to obtain a dense film. The crystalline phase of the film was related to the Y6FA concentration in the gas phase using x-ray diffraction. Depth profiling, using x-ray photoelectron spectroscopy, showed that Y is present (fairly uniform) at all depths of the film. Growth rates are dependent on the applied power but independent of substrate temperature. Film density, however, shows a significant dependence on substrate temperature.

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38

VALLEJO, N. DIAZ, O. SANCHEZ, J. C. CAICEDO, W. APERADOR, and G. ZAMBRANO. "HOT CORROSION OF YTTRIUM STABILIZED ZIRCONIA COATINGS DEPOSITED BY AIR PLASMA SPRAY ON A NICKEL-BASED SUPERALLOY." Surface Review and Letters 24, no. 06 (November 24, 2016): 1750084. http://dx.doi.org/10.1142/s0218625x17500846.

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In this research, the electrochemical impedance spectroscopy (EIS) and Tafel analysis were utilized to study the hot corrosion performance at 700[Formula: see text]C of air plasma-sprayed (APS) yttria-stabilized zirconia (YSZ) coatings with a NiCrAlY bond coat grown by high velocity oxygen fuel spraying (HVOF), deposited on an INCONEL 625 substrate, in contact with corrosive solids salts as vanadium pentoxide V2O5 and sodium sulfate Na2SO4. The EIS data were interpreted based on proposed equivalent electrical circuits using a suitable fitting procedure performed with Echem AnalystTM Software. Phase transformations and microstructural development were examined using X-ray diffraction (XRD), with Rietveld refinement for quantitative phase analysis, scanning electron microscopy (SEM) was used to determinate the coating morphology and corrosion products. The XRD analysis indicated that the reaction between sodium vanadate (NaVO[Formula: see text] and yttrium oxide (Y2O[Formula: see text] produces yttrium vanadate (YVO[Formula: see text] and leads to the transformation from tetragonal to monoclinic zirconia phase.

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39

Sharma, Renu. "HREM studies of structure, defects and phase transformation in zirconia and Mn stabilised zirconia." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (August 1990): 824–25. http://dx.doi.org/10.1017/s0424820100177258.

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Zirconia is known to exist in three different structure types: monoclinic, tetragonal and cubic. Monoclinic is the room temperature form that transforms to tetragonal and finally to cubic at progressively higher temperatures. The monoclinic to tetragonal transformation is reversible, exhibits hysteresis and has been widely studied by thermal analysis, high temperature x-ray diffraction and electron diffraction. This transformation has an undesirable effect on some materials properties. The cubic form of zirconia has been stabilised with yttria, calcia, alumina and magnesia. The decomposition of zirconium carbonate and zirconium manganese carbonate to the respective oxides and their phase tranformation has been studied in situ by electron diffraction and high resolution electron microscopy (HREM) and the results are reported here.The carbonates used in these studies were precipitated from their aqueous solution. Thin crystal fragment were dispersed on holey carbon grids using a suspension in ethanol. A JE0L 4000EX microscope, with double tilt goniometer and on-line Digital MicroVAX II image-analysis system, operating at 400KV, was used for HREM studies.

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40

Belot, John A., Richard J. McNeely, Anchuan Wang, Charles J. Reedy, Tobin J. Marks, Glenn P. A. Yap, and Arnold L. Rheingold. "Expedient route to volatile zirconium metal-organic chemical vapor deposition precursors using amide synthons and implementation in yttria-stabilized zirconia film growth." Journal of Materials Research 14, no. 1 (January 1999): 12–15. http://dx.doi.org/10.1557/jmr.1999.0004.

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This communication reports rapid, efficient syntheses of the zirconium-organic metal-organic chemical vapor deposition (MOCVD) precursors Zr(acac)4 and Zr(dpm)4 (acac = acetylacetonate; dpm = dipivaloylmethanate) as well as a new, highly volatile, air- and moisture-stable Zr precursor based on a tetradentate Schiff-base ligand, Zr(tfacen)2 (tfacen = bis-trifluoroacetylacetone-ethylenediiminate). The improved one-step synthetic routes employ tetrakis(dimethylamido)zirconium as a common intermediate and represent a major advance over previous methods employing ZrCl4 or diketonate metathesis. Furthermore, Zr(tfacen)2 is shown to be an effective metal-organic precursor for the MOCVD-mediated growth of (100) oriented yttria-stabilized zirconia thin films.

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41

Mityushova, Yulia A., Sergey A. Krasikov, Alexey A. Markov, Elmira I. Denisova, and Vadim V. Kartashov. "Effect of a stabilizing additive on the electroconductivity of ZrO2-based ceramics." Butlerov Communications 58, no. 5 (May 31, 2019): 105–9. http://dx.doi.org/10.37952/roi-jbc-01/19-58-5-105.

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The creation of solid oxide fuel cells (SOFC) is one of the promising solutions to the problem of electricity supply. It is advantageous to use stabilized zirconium dioxide (ZrO2) as solid electrolytes in SOFC. In this paper, zirconium dioxide powders with additives of yttrium and scandium oxides (ZrO2–Y2O3, ZrO2–Sc2O3 and ZrO2–Y2O3–Sc2O3) were synthesized. Ceramic samples were obtained from the powders to study the effect of stabilizing additives on the conductive properties of zirconium dioxide. The addition of yttrium oxide Y2O3 in an amount of 8 mol. % contributed to the formation of a solid cubic solution of zirconium dioxide, and scandium oxide Sc2O3 increased the strength and conductive characteristics of the material. The definition of the conductive characteristics was carried out by impedance spectroscopy. Platinum paste was preliminarily applied by printing, which, when measured, ensured contact with the entire surface of the sample under study. It is shown that the addition of yttrium oxide contributes to the formation of a solid cubic solution of zirconium dioxide, and scandium oxide increases the strength (microhardness) and conductive characteristics of the material. Of interest is the simultaneous alloying of zirconium dioxide with scandium and yttrium oxides. The results of determining the properties of ceramic samples showed that the increase in electrical conductivity is more influenced by the addition of Sc2O3 compared with the addition of Y2O3. Stabilization without yttrium oxide leads to unstable conductivity values over time. A sample of ZrO2 – 1 mol%. – Y2O3 – 8 % mol. Sc2O3 has the potential to be used as an electrolyte in solid oxide fuel cells.

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42

Lee, Jong-Sook, and Doh-Yeon Kim. "Space-charge concepts on grain boundary impedance of a high-purity yttria-stabilized tetragonal zirconia polycrystal." Journal of Materials Research 16, no. 9 (September 2001): 2739–51. http://dx.doi.org/10.1557/jmr.2001.0374.

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A detailed impedance analysis using the brick-layer model is performed on a high-purity yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Space-charge impedance is generally formulated and expressions for the respective space-charge models are therefrom derived depending on whether dopant ions are mobile or immobile. Pronounced yttrium segregation in Y-TZP is also considered in the analysis in that the dopant profile is assumed to be frozen from a high-temperature equilibrium distribution. Comparison with experimental observations shows that the electrically measured grain-boundary thickness corresponds to the Schottky-barrier width, slightly modified by the dopant segregation. The grain-boundary resistance is not consistent with any space-charge models and the strong defect interaction due to the yttrium enrichment is suggested to be mainly responsible.

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43

Silva, Yankel B. F., Wilson Acchar, and Vamberto Monteiro Silva. "Feasibility Study of Zirconia Waste Recycling Obtained during the Machining of Single and Multiple Dental Prosthesis." Materials Science Forum 881 (November 2016): 387–91. http://dx.doi.org/10.4028/www.scientific.net/msf.881.387.

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Zirconia ceramic stabilized with 3% yttria (3Y - TZP) is the most used ceramic dental materials. During the machining of zirconia blocks in the laboratory to prepare the various types of prostheses, much of the material is lost in powder form, which is subsequently discarded. This study investigates the possibility to recycling of zirconium oxide powder obtained during milling of dental crowns and bridges. Uniaxial and isostatic pressed samples were prepared, sintered and compared to the commercial material. The results indicated that the isostatic pressed samples shows good physical and mechanical properties, comparable to the commercial material, demonstrating the viability to use this recycle material in the same process.

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44

Tolkachev, Oleg S., Yuriy Ivanov, Аnatoly Klopotov, Vladimir Klopotov, and Yuriy Abzaev. "Structural Phase State of the Ceramic Layer of ZrO₂." Advanced Materials Research 1085 (February 2015): 303–6. http://dx.doi.org/10.4028/www.scientific.net/amr.1085.303.

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The results of the X-ray phase and thermodynamic analysis of phase formation in the Zr-Y-O system which is the initial material for formation of yttrium of stabilized ceramics on the basis of dioxide of zirconium are presented. It is established that the material is multiphase and contains monoclinic, cubic and tetragonal modifications of dioxide of zirconium which weight ratios differ considerably.

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45

Al-Attar, Abeer Farouk Abbas. "Effect of Mechanical Alloying on Structural and Electrical Properties of (P₂O₅)_(x)-(Y₂O₃)_(0.03)-(ZrO₂)_(0.97) Electrolyte." Key Engineering Materials 900 (September 20, 2021): 155–62. http://dx.doi.org/10.4028/www.scientific.net/kem.900.155.

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Pentavalent phosphorous oxide doped yttria-stabilized zirconia (P2O5)X-(Y2O3)0.03-(ZrO2)0.97 with x=0.06 mol.% was achieved via an economical technique using mechanical alloying (MA) technique. Three types of nanocomposite powders of electrolyte were produced by high-energy ball milling with different milling times. The phases of synthesized electrolyte powders and sintered electrolytes were illustrated by X-ray diffraction (XRD). The average particle sizes of powders indicated around (360, 245, and 48) nm at milling duration (1, 10, and 45) hrs, respectively. The XRD analysis results of 1 h MA electrolyte powder obtained tetragonal ZrO2, while the 45 h MA electrolyte manifested a minority phase of monoclinic ZrO2. Then, the XRD of the sintered electrolyte with the optimum electrical properties appeared two phases. The major phase of the tetragonal zirconium yttrium oxide and a minor phase was a monoclinic zirconium oxide. The average grain sizes of the three types of the sintered manufacturing electrolytes were (7.638, 2.642, and 1.245 µm) after the mechanical alloying duration of (1, 10, and 45) hrs, respectively and sintered at 1873 °K. The DC conductivity (σ) studied corresponded to the influence of milling times on the microstructure for each sintered electrolyte. From the results, the synthesized sintered electrolyte with a long MA duration gave a maximum DC (σ) 1.03E-1S.m. And, the DC conductivity (σ) was 1.11E-02 of electrolyte produced with 10 hr mechanical alloying. Otherwise, the lower DC conductivity got with the electrolyte prepared in the lowest milling duration was 8.9 E-2 S.m.

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46

Rahmawati, Fitria, Anang Pandan Respati, Mudjijono Mudjijono, and Dani G. Syarif. "Samarium-Doped Ceria/Yttria-Stabilized Zirconia Composite Prepared by Solid State Reaction." Chemistry & Chemical Technology 12, no. 4 (December 10, 2018): 434–40. http://dx.doi.org/10.23939/chcht12.04.434.

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47

Muñoz, R. A., J. E. Rodriguez, and Cosme Roberto Moreira Silva. "Study of Polymorphs of Zirconia in the System ZrO₂: ƞ wt% Re₂O₃ Obtained by Polymeric Precursor Method." Materials Science Forum 727-728 (August 2012): 1340–44. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.1340.

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In this paper we propose the stabilization of zirconium oxide with controlled additions of a rare earth elements concentrate, in the system ZrO2: ƞ wt% Re2O3 (withƞ=5.36, 10.47, 13.74, 16.91 e 20) whereRe2O3is a rare earth elements concentrate composed mainly of 76.88% of yttrium oxide, 12.1% of Dysprosium oxide, 4.04% of Erbium oxide and 1.94% of Holmium oxide. The synthesis method used was the Pechini method. The results show that additions of 5.36 and 20 wt% of the concentrate are enough to stabilize the tetragonal and cubic zirconia phases respectively, and that zirconium oxide polymorphs can coexist with additions within these limit. In the characterization of the obtained powders are presented and discussed the following results: differential scanning calorimetry, transmission electron microscopy and X-ray diffraction. Also, it was necessary to make analysis by Rietveld refinement because they had severe overlap in the diffraction peaks. One of the most relevant results is obtaining a raw material, cheap to be used in many technological applications.

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48

Lin, Yung-Jen, Peter Angelini, and Martha L. Mecartney. "Analytical TEM study of a yttria stabilized zirconia/glass composite." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 572–73. http://dx.doi.org/10.1017/s0424820100104923.

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Yttria stabilized zirconia is a versatile ceramic material. It can be used for structural components or as a solid electrolyte. Its properties (such as high toughness) are strongly affected by the microstructure. In partially stabilized zirconia, the high toughness is mainly due to the toughening effect of a tetragonal (t) to monoclinic (m) phase transformation in the vicinity of a crack. Retention of tetragonal zirconia at room temperature is important for fabricating transformation toughened materials. To completely retain tetragonal zirconia at room temperature the grain size of the material must be less than a critical size. In yttria stabilized zirconia this critical grain size depends on the yttria concentration. Grain growth of yttria stabilized zirconia is also influenced by the amount of yttria in the grains. These previous studies, however, have focused on the behavior of materials with minimal glassy grain boundary phases. In contrast, in commercial polycrystalline zirconia often a significant amount of glassy grain boundary phase is present. This current research seeks to elucidate the effects of these grain boundary phases on the grain growth in yttria stabilized zirconia ceramics.

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Wang, Xiao-Gang. "Yttrium segregation and surface phases of yttria-stabilized zirconia (111) surface." Surface Science 602, no. 1 (January 2008): L5—L9. http://dx.doi.org/10.1016/j.susc.2007.11.007.

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50

Tolkachev, Oleg S., Yurii F. Ivanov, Anatolii A. Klopotov, Vladimir D. Klopotov, and Olga Shaykina. "Phase Composition of Zirconium Dioxide Stabilized with Yttrium." Advanced Materials Research 1013 (October 2014): 108–14. http://dx.doi.org/10.4028/www.scientific.net/amr.1013.108.

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The results of X-ray and thermodynamic analysis of the phase formation in the system Zr-YO, which is the starting material for the formation of yttrium-stabilized ceramic zirconia. Found that the material is multiphase and contains monoclinic, cubic and tetragonal zirconia weight ratios which vary considerably.

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Journal articles on the topic 'Yttrium stabilised zirconium'

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