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Properties of composition sinter prepared from fibrous barium titanate and nanometer zirconia

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Journal of Harbin Institute of Technology(New Series) 2002年第2期9卷 193-195页

作者：李文旭姜兆华王福平 Dept. of Appl. Chem. Harbin Inst. of Technol. Harbin 150001 China

Fibrous Batium Titanate particles, 30 50 μm long, prepared by a hydrothermal reaction, and the monoclinic phase and nanometer zirconia, 11.6 nm long were prepared by citric acid reaction respectively. Then, the two were composite sintered to produce a new functional material by making full use of crystal axis orientation of fibers and the activity of nanometer powder. The analydid of composition and microstructure of the new material in terms of XRD and SEM. shows that the solid solution was formed between fibers and nanometer powder, and the distance between lattice (d value) of Barium Titanate changed. But the crystal axis orientations of fibers remain unchanged.

关键词： fibrous Barium Titanate nanometer zirconia distance between lattice orientation

Comparative Evaluation of the Implant Made of Yttrium-partially Stabilized zirconia and Pure Titanium on Stress Distribution by Anisotropic Finite Element Method

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Journal of Wuhan University of Technology(Materials Science) 2005年第B12期20卷 147-149页

作者：满毅宫苹 West China Stomatology College Sichuan University Chengdu 610041 China

The purpose of this research is to analyze and compare stress distribution patterns around dental implant made of pure titanium and yttrium-partial stabilized zirconia （YPSZ） in anisotropic versus isotropic finite element method under vertical and oblique loads. Although the properties of implant and crown were changed, similar stress distribution and close stress level were observed in two different implant finite element models. The stress values were a little lower in the YPSZ model. In the bone, anisotropy increased the stress values by 30%- 70% in the isotropic cases. The YPSZ implant could be more valuable choice for implant because of esthetic requirement. Anisotropy had subtle, yet significant effects on the stress level.

关键词： finite element anisotropic elasticity zirconia implant

STUDIES ON THE WET CHEMICAL PREPARATION AND REGULARITY OF PHASE TRANSFORMATION OF zirconia ULTRAFINE PARTICLES

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Chinese Science Bulletin 1992年第5期37卷 423-427页

作者：余家国潘牧张联盟 Research Institute of Advanced Materials Wuhan University of Technology Wuhan 430070 PRC

zirconia is an important material of transformation toughening. Consequently, a clear understanding of the regularity of phase transformation, a full realization of all forms of zirconia, and a deep investigation into the methods of preparation and even dispersion of high purity ZrO2 ultrafine particles （henceforth simplified as ZrO2 UFP ） will undoubtedly stimu-

关键词： zirconia ultrafine particles wet chemical method a critical particle size

Phase Relationship and Properties of MgO Stabilized zirconia as a Variation of the Sintering Conditions and the Chemistry

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China's Refractories 2017年第2期26卷 7-12页

作者： BORGER A PRIESE A LORICOURT J Center for Abrasives and Refractories Research and Development(C.A.R.R.D.)GmbH Villach 9524Austria Imerys Fused Minerals Murg GmbH Laufenburg 79725Germany

In this paper we present the results of studies on making MgO zirconia sintered parts（ intended to be used as metering nozzles in continuous casting of steel） from monoclinic zirconia and MgO powders via a granulation process. The parts were pressed and sintered under different conditions,and analysed for physical properties,microstructure and phase composition. We found a strong influence of the MgO concentration and the sintering cycle,especially the cooling rate on the thermal shock resistance. The paper concludes with recommendations for the production of zirconia metering nozzles in an economic way.

关键词： zirconia magnesia refractory granula-tion metering nozzles

Outstanding high-temperature oxidation-and wear-resistance of WC based cermets

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Journal of Materials Science & Technology 2023年第24期155卷 33-46页

作者： Wentao Jiang Hao Lu Xuemei Liu Haibin Wang Dongyang Li Chao Liu Mingsheng Wang Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional Materials Ministry of Education of China Beijing University of Technology Beijing 100124 China Department of Chemical & Materials Engineering University of Alberta Edmonton Alberta T6G 2H5 Canada Xiamen Tungsten Co. Ltd. Xiamen 361009 China

The interaction between oxidation and frictional load can greatly deteriorate the performance of ceramic-metal composites.In this work,we used WC-Co cermet as a representative of ceramic-metal composites to study its wear failure behavior and protection effectiveness.It is found that a transition of wear mechanism from mechanical wear to oxidative wear occurs with increasing temperature.The addition of zirconia can significantly improve the anti-oxidation performance and load-bearing capacity of the cermet under the frictional load.This is mainly attributed to the modulation of the tribo-oxide layer constitutions and changes in surface morphology.The zirconia component facilitates the formation of a dense protective oxide layer and reduces the content of brittle oxides on the worn surface.Based on the understanding of the temperature-and oxidation-induced compositional and microstructural evolutions at the sliding contact surface and subsurface,a promising approach is proposed for developing ceramic-metal composites with high wear resistance and anti-oxidation capability.

关键词： Cermet Anti-oxidation performance Wear mechanism zirconia

Influence of Impurities of Zircon Sand on the Microstructure of Fused zirconia Grains for Continuous Casting of Steel Refractories

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China's Refractories 2018年第1期27卷 1-7页

作者： Andreas BORGER Johan LORICOURT Angelika PRIESE Center for Abrasives and Refractories Research and Development (C.A.R.R.D.) GmbH Villach 9524 Austria Imerys Fused Minerals Murg GmbH Laufenburg 79725 Germany

Certain impurities of zircon sands, especially alumina, titania, calcia and yttria cannot be completely re- moved in the production of fused zirconia and may have an influence on the corrosion resistance and other product properties of refractories for continuous casting of steel. In this paper, we present our findings on how impurities in raw materials end up in different stabilised zirconia refractory grains, in particular calcia-, magnesia- and yttria-stabilised zirconia. The microstructure （and phase composition） is affected by both the raw materials and the fusion conditions （furnace type and cooling technology）.

关键词： zirconia zircon impurities stabilisation microstructure impurity phases

Thickness dependence of the crystallization and phase transition in ZrO_(2)thin films

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Journal of Advanced Ceramics 2023年第4期12卷 822-829页

作者： Yue Guan Jing Zhou Haodong Zhong Weipeng Wang Zhengjun Zhang Feng Luo Shuai Ning School of Materials Science and Engineering Smart Sensing Interdisciplinary Science CenterNankai UniversityTianjin 300350China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Fluorite-structure binary oxides(e.g.,HfO_(2)and ZrO_(2))have attracted increasing interest for a broad range of applications including thermal barrier coatings,high-k dielectrics,and novel ferroelectrics.A crystalline structure plays a crucial role in determining physical and chemical properties.Structure evolution of ZrO_(2)thin films,particularly down to the nanometer scale,has not been thoroughly studied.In this work,we carried out systematic annealing analysis on the ZrO_(2)thin films.Through in-situ high-temperature X-ray diffraction(XRD)characterizations,a thickness dependence of crystallization and phase transition is observed.Irrespective of the thickness(10-300 nm),the as-prepared amorphous ZrO_(2)thin films are preferentially crystallized into a tetragonal(t)structure(high-temperature phase),which can be preserved down to room temperature(RT)upon anncaling at the corresponding crystallization temperaturc(T).When anncaling at temperaturcs higher than Tc,the transition from t to monoclinic(m;RT phase)will occur,and the quantity of the transition strongly depends on the film thickness.Our work expands the basic understanding of the phase transition in the ZrO_(2)thin films,and offers a path to the selective control over the phase structure for novel functionalities.

关键词： zirconia crystallization tetragonal(t) monoclinic(m) phase transition

Influence of ZrO_(2)/SiO_(2) nanomaterial incorporation on the properties of PEO layers on Mg-Mn-Ce alloy

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Journal of Magnesium and Alloys 2022年第2期10卷 552-566页

作者： D.V.Mashtalyar I.M.Imshinetskiy K.V.Nadaraia A.S.Gnedenkov S.L.Sinebryukhov A.Yu.Ustinov A.V.Samokhin S.V.Gnedenkov Institute of Chemistry Far Eastern BranchRussian Academy of SciencesVladivostok 690022Russian Federation Far Eastern Federal University Vladivostok 690922Russian Federation A.A.Baikov Institute of Metallurgy and Materials Science Russian Academy of SciencesMoscow 119991Russian Federation

The properties of coatings formed on the MA8 magnesium alloy by the plasma electrolytic oxidation in electrolytes containing mechanical mixture of zirconia and silica nanoparticles in concentrations of 2,4 and 6 g/l have been investigated.It has been established by SEM,EDS,and XPS that ZrO_(2)/SiO_(2)nanoparticles successfully were incorporated into the coatings.Micro-Raman spectroscopy showed the presence of ZrO_(2)in tetragonal and monoclinic forms in the PEO-coating composition as well as Mg_(2)SiO_(4) in tetrahedral configuration uniformly distributed in the outer part of coatings.Obtained coatings significantly reduce corrosion current density in comparison with bare Mg alloy and base PEOlayer(from 2.4×10^(–7)A/cm^(2) for base PEO layer to 0.7×10^(–7)A/cm^(2) for coatings with nanoparticles).It has been found that the presence of solid nanoparticles in the composition of coating has a positive effect on their hardness(this parameter was increased from 2.1±0.3 GPa to 3.1±0.4 GPa)and wearproof(the wear was reduced from(4.3±0.4)×10^(–5)mm^(3)/(N×m)to(3.5±0.2)×10^(–5)mm^(3)/(N×m)).

关键词： Plasma electrolytic oxidation Composite coatings Nanoparticles zirconia Silica Protective coatings

Advanced Alumina and zirconia Ceramics Produced by the Electroconsolidation Method

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China's Refractories 2016年第1期25卷 39-43页

作者： Sergii Y. SAIENKO Yevhenii O. SVITLYCHNYI Konstiantyn V. LOBACH Oleksandr Y. SURKOV National Science Centre Kharkov Institute of Physics and Technology Kharkov 61108 Ukraine

The possibility to produce advanced alumina and zirconia ceramics by the electroconsolidation method is studied. The technological parameters of Al2O3 and ZrO2 （3 mass% Y2O3 ） production were developed and optimized. Electroconsolidated alumina and zirconia ceramics have higher values of properties in comparison with ordinary sintered samples in air. Advanced proper- ties of electroconsolidated ceramics are defined by homo- geneous, ultradense and fine-crystalline structure that was formed due to the effect to consolidate the materials to high density for a shortest time.

关键词： alumina zirconia electroconsolidation dense structure high properties advanced ceramics