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.

Roughness and its effects on flexural strength of dental yttria-stabilized zirconia ceramics

2019 ◽  
Vol 739 ◽  
pp. 149-157 ◽  
Author(s):  
José Eduardo Vasconcellos Amarante ◽  
Marcos Venícius Soares Pereira ◽  
Grace Mendonça de Souza ◽  
Manuel Fellipe R. Pais Alves ◽  
Bruno Galvão Simba ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics

Thermal Cycling Effect on Mechanical Properties of Yttria-Stabilized Tetragonal Zirconia

2013 ◽  
Vol 538 ◽  
pp. 121-124
Author(s):  
Jing Zhang
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Cycling ◽  
Tetragonal Zirconia ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Optical Applications ◽  
The Stability

Yttria-stabilized zirconia (YSZ) is an important material in the area of energy and optical applications. In this study, the mechanical properties (Young’s modulus, Vickers hardness, flexural strength, and coefficient thermal expansion) and physical properties (phase transition) of yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) was reported. The effect of thermal cycling on the mechanical properties and the stability was also evaluated.

scholarly journals The Effect of Yttria-Stabilized Zirconia on the Properties of the Fluorine-Substituted Hydroxyapatite Ceramics Prepared by Pressureless Sintering

2008 ◽  
Vol 1 ◽  
pp. 57-68 ◽  
Author(s):  
Y. Chen ◽  
Z. Dong ◽  
X. Miao
Keyword(s):  
Mechanical Properties ◽  
Thermal Decomposition ◽  
Sol Gel ◽  
Yttria Stabilized Zirconia ◽  
Pressureless Sintering ◽  
Stabilized Zirconia ◽  
Gel Method ◽  
Zirconia Composites ◽  
Zirconia Phase ◽  
Hydroxyapatite Phase

Hydroxyapatite-zirconia composites have received much attention during the last decade due to their combination of the desirable mechanical properties of zirconia and the excellent bioactivity of hydroxyapatite (HA). However, thermal decomposition of the hydroxyapatite phase and reaction between the zirconia phase and the hydroxyapatite phase remain a major problem in the hydroxyapatite-zirconia composites. In this study, thermally stable and fluorine-substituted hydroxyapatite (Ca10(PO4)6(OH)0.8F1.2; coded as HA06F) was prepared by a sol-gel method to replace the hydroxyapatite. Yttria-stabilized zirconia (YTZP) was also prepared by a sol-gel method in order to produce HA06F-YTZP composites with 5, 10, 15, 20, 40, and 60 wt% YTZP by simple and cost-effective pressureless sintering. Thermogravimetric analysis (TGA) and x-ray diffraction (XRD) of the HA06F-YTZP composites showed that the thermal stability of the HA06F matrices could be maintained when the YTZP content did not exceed 20 wt% and for sintering temperatures less than 1400 oC. Dilatometric analysis and microstructural observation revealed that the YTZP phase in the HA06F-YTZP composites retarded the densification of the composites if the zirconia content was over 20 wt%. Electron scanning microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM) of the HA06F-YTZP composites showed that the YTZP second phase had a size in the nanometer scale and the reaction between the HA06F phase and the zirconia phase was suppressed. Mechanical properties including the Knoop hardness, the Young’s modulus, and the fracture toughness of the HA06F-YTZP composites increased with the YTZP content until the optimal content of 20 wt%; higher YTZP contents led to low mechanical properties due to poor densification of the composites and the severe thermal decomposition of the HA06F phase. The optimal HA06F-20YTZP composite also showed desirable attachment and proliferation of osteoblast cells. Nevertheless, the study of the composite system indicated the limitations of the pressureless sintering technique. To achieve the full potential of the composites for medium or low load bearing applications, a pressure-assisted sintering technique would still be necessary.

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.

Sign in / Sign up

Export Citation Format

Share Document