Mechanical properties of ytterbia stabilized zirconia ceramics (Yb-TZP) fabricated from powders prepared by co-precipitation method

2000 ◽  
Vol 26 (2) ◽  
pp. 207-211 ◽  
Author(s):  
Susumu Nakayama ◽  
Sachihiko Maekawa ◽  
Tetsuji Sato ◽  
Yoshio Masuda ◽  
Shinji Imai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Precipitation Method ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Co Precipitation

scholarly journals Investigating the effect of yttria contents on the structure and mechanical properties of zirconia ceramics

2016 ◽  
Vol 19 (4) ◽  
pp. 232-240
Author(s):  
Linh Ba Ngoc Nguyen ◽  
Dung Van Hoang ◽  
Van Thi Thanh Tran
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Critical Concentration ◽  
Annealing Process ◽  
Yttria Stabilized Zirconia ◽  
Precipitation Method ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Grain Sizes ◽  
Co Precipitation

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.

Effect of small amount of alumina on structure, wear and mechanical properties of 3Y-TZP ceramics

2014 ◽  
Vol 11 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Igor Danilenko ◽  
Serhii Prokhorenko ◽  
Tetyana Konstantinova ◽  
Leonid Ahkozov ◽  
Valerii Burkhovetski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Composite Structures ◽  
Tribological Behavior ◽  
Ceramic Composites ◽  
Synthesis Methods ◽  
Zirconia Ceramics ◽  
Alumina Composites ◽  
Co Precipitation ◽  
Metallic Parts

The use of ceramic instead of metallic parts in devices that operate in aggressive conditions increases the service life of machines and equipment for chemical, metallurgical and other industries. The wear resistant zirconia/alumina composites were sintered from nanopowders obtained by co-precipitation technique. In the case of addition of 1wt% of alumina in zirconia ceramics the wear resistance increased by approximately 30%.The formation of complex multilevel composite structures, such as Al3+ ion segregation on zirconia grain boundaries and intracrystalline alumina inclusions in zirconia grains, increased the fracture toughness values of composites obtained from co-precipitated nanopowders and consequently decreased the volume loss of ceramic material.In this study, we investigated the effect of nanopowders synthesis methods and alumina concentration on composite structure, fracture toughness and tribological behavior of 3Y-TZP/alumina ceramic composites and searched correlation between structures and mechanical properties.

Influence of Cadmium Substitution on Structural and Mechanical Properties of Co‐Ni Nano Ferrite Synthesized by Co‐Precipitation Method

2020 ◽  
Vol 393 (1) ◽  
pp. 1900213
Author(s):  
Akshay B. Kulkarni ◽  
Nagaraj D. Hegde ◽  
Shashidhara Gowda H. ◽  
S. N. Mathad
Keyword(s):  
Mechanical Properties ◽  
Precipitation Method ◽  
Co Precipitation

Microstructure and Mechanical Properties of Multiscale Zirconia Ceramics Prepared by Field Assisted Sintering Technique

2016 ◽  
Vol 697 ◽  
pp. 354-359
Author(s):  
Khalid Eltayeb ◽  
Dong Qin Jin ◽  
Young Hwan Han ◽  
Fei Chen ◽  
Qiang Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Yttria Stabilized Zirconia ◽  
Milling Machine ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Dense Structure ◽  
Zirconia Composites ◽  
20 Nm ◽  
Field Assisted Sintering

Two kinds of powders of 3 mol. % yttria stabilized zirconia (3Y–TZP) with different particles sizes; one was 20 nm denoted by N whereas the other was 0.5 µm denoted by M, were mechanically mixed via ball milling machine using different amounts of N wt. % to obtain multiscale zirconia composite powder. Then the mixed powders were sintered by field assisted sintering technique (FAST). The effect of N content on the microstructure as well as on mechanical properties of zirconia is investigated. Results show that the microstructure of M completely surrounded by N emerged in zirconia composites, and tetragonal phase is presented in all the sintered samples. The obtained zirconia ceramics with 15 wt. % N own a highly dense structure (~ 99.9 % relative density) and high flexural strength of 813.59 MPa wherein a 15 % increase in flexural strength compared to zirconia ceramics without adding N, but the fracture toughness of the composites just lightly decreases. The improved flexural strength of the composites is caused by the multiscale effect.

Preparation of Chitosan - Hydroxyapatite Nanocomposites

2011 ◽  
Vol 284-286 ◽  
pp. 1760-1763
Author(s):  
Jing Xian Zhang ◽  
Dong Liang Jiang ◽  
Qing Ling Lin ◽  
Zhong Ming Chen ◽  
Zheng Ren Huang
Keyword(s):  
Mechanical Properties ◽  
Fourier Transform ◽  
Phase Composition ◽  
Fourier Transform Infrared ◽  
Chitosan Solution ◽  
Precipitation Method ◽  
Solution Ph ◽  
Cylindrical Form ◽  
Infrared Spectrometer ◽  
Co Precipitation

Chitosan/Hydroxyapatite composites with a homogeneous nanostructure have been prepared by a co-precipitation method. Initially, a chitosan solution was prepared and mixed with the (NH4)2HPO4 solution. After homogenizing, the obtained chitosan/ (NH4)2HPO4 solution was gradually dropped into the Ca (NO3)2.4H2O solution under stirring. The solution pH was adjusted to 9 using NH3.H2O. The precipitate was compressed into a cylindrical form followed by post treatment. The microstructure, phase composition and mechanical properties of the resulting chitosan-HAp composites were characterized. In the presence of chitosan, HAp crystallites were found to be well aligned along the c-axes in the respective aggregates. Fourier transform infrared spectrometer results indicated that an intermolecular bridging complexes might have been developed between the chitosan and HAp. The compact composites obtained were mechanically flexible, the highest strength was found to be 38.4 MPa for chitosan/HAp samples with a 20 wt% of chitosan.

Effect of pressure on the phase transformations and mechanical properties of 10 mol% Mg-PSZ sintered by HPHT

CrystEngComm ◽  
2022 ◽  
Author(s):  
Jian Wang ◽  
Zhiwen Wang ◽  
Yongkui Wang ◽  
Hongan Ma ◽  
Shuai Fang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Temperature ◽  
Phase Transformations ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Effect Of Pressure ◽  
High Pressure High Temperature

MgO (10 mol%)-stabilized zirconia ceramics were obtained using high-pressure high-temperature (HPHT) sintering. The effects of the sintering pressure (2.5, 3.7, and 5.0 GPa) on the phase transformations and hardness were...

Microstructural and Mechanical Properties of Polymer-Based Scaffolds Reinforced by Hydroxyapatite

2007 ◽  
Vol 544-545 ◽  
pp. 765-768 ◽  
Author(s):  
Hyeong Ho Jin ◽  
Won Ki Lee ◽  
Hong Chae Park ◽  
Seog Young Yoon
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Yield Strength ◽  
Pore Size ◽  
Compressive Modulus ◽  
Precipitation Method ◽  
Pore Morphology ◽  
Composite Scaffolds ◽  
Co Precipitation

Various polymer-based scaffolds reinforced by the hydroxyapatite (HAp) for bone tissue engineering were successfully synthesized by in-situ co-precipitation method. The influence of HAp in composite scaffolds on the pore morphology, microstructure, and mechanical properties was investigated. The polymer-based scaffolds appeared to be macroporous and an interconnected open pore microstructure with pore size around 200 μm. The pore structure of the composite scaffolds was not much changed by the presence of HAp but the pore size of the composite scaffolds decreased with adding the HAp. The compressive modulus and yield strength of the polymer-based scaffolds improved by the presence of HAp.

scholarly journals Two-Step Sintering of Partially Stabilized Zirconia for Applications in Ceramic Crowns

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1857
Author(s):  
Bobby Aditya Darmawan ◽  
John G. Fisher ◽  
Doan Thanh Trung ◽  
Kumaresan Sakthiabirami ◽  
Sang-Won Park
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tooth Enamel ◽  
Milled Powder ◽  
Second Step ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Partially Stabilized Zirconia ◽  
Ceramic Crowns ◽  
Equal Density

Partially-stabilized zirconia is used in ceramic crowns due to its excellent mechanical properties and bio-inertness but does not match the natural color and translucency of tooth enamel. To reduce scattering of light and improve translucency, the grain size of zirconia ceramics should be less than the wavelength of visible light (0.4–0.7 μm), and porosity should be eliminated. The aim of the present work was to study the effect of two-step sintering of a commercial powder (Zpex Smile, Tosoh Corp., Tokyo, Japan) on the grain size and translucency of zirconia for use in ceramic crowns. Samples were sintered at a first step temperature (T1) of 1300, 1375 and 1400 °C for 5 min, followed by a decrease to the second step temperature (T2) and holding at T2 for 5–20 h. Samples were also conventionally sintered at 1450 °C for 2 h for comparison. Two-step sintered samples with an almost equal density, smaller grain size and narrower grain size distribution compared to conventionally sintered samples could be sintered. However, the translucency of two-step sintered samples had lower values compared to conventionally sintered samples. This is due to the slightly higher porosity in the two-step sintered samples. Density and translucency of both conventionally and two-step sintered samples could be increased further by using a ball milled powder.

Determining europium compositional fluctuations in partially stabilized zirconia nanopowders: a non-line-broadening-based method

2016 ◽  
Vol 72 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Riccardo Marin ◽  
Gabriele Sponchia ◽  
Michele Back ◽  
Pietro Riello
Keyword(s):  
Tetragonal Phase ◽  
Rietveld Analysis ◽  
Lattice Parameters ◽  
Crystalline Lattice ◽  
Precipitation Method ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Log Normal ◽  
Co Precipitation

A method is reported for assessing the compositional fluctuations in a ceramic sample, based only on the determination of the crystalline lattice parameters. Pure tetragonal phase partially stabilized zirconia powders are synthesized through the co-precipitation method by incorporating 4% Eu3+. The powder is subjected to compression cycles to promote the tetragonal-to-monoclinic transformation. The Rietveld analysis of the X-ray powder diffraction patterns, recorded after each compression cycle, gives information about the lattice parameters and monoclinic phase content. The determination of europium content in the residual tetragonal phase is accomplished considering the unit cell volume oft-ZrO2using Vegard's law. Using this information the compositional fluctuations over the sample were determined by considering two possible distributions of lanthanide ion content in the powders: a Gaussian and a Log-normal one. It was found that the Gaussian distribution better fits the experimental data. It was eventually demonstrated that these results are physically meaningful.

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