Effect of Cation Dopant on Phase Stability of Zirconia Bioceramics in Hot Water

2006 ◽  
Vol 49 ◽  
pp. 97-102 ◽  
Author(s):  
Yorinobu Takigawa ◽  
Yukihisa Naka ◽  
Kenji Higashi
Keyword(s):  
Phase Transformation ◽  
Phase Stability ◽  
Ionic Radius ◽  
Hot Water ◽  
Yttria Stabilized Zirconia ◽  
Transformation Behavior ◽  
Stabilized Zirconia

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.

Effect of Small Amount of Dopant on Phase Stability of Zirconia Bioceramics

2007 ◽  
Vol 561-565 ◽  
pp. 1561-1564
Author(s):  
Yorinobu Takigawa ◽  
Tokuteru Uesugi ◽  
Kenji Higashi
Keyword(s):  
Phase Transformation ◽  
Binding Energy ◽  
Phase Stability ◽  
Ionic Radius ◽  
Nearest Neighbor ◽  
Axial Ratio ◽  
Xrd Analysis ◽  
Hot Water ◽  
Transformation Behavior ◽  
Cation Site

The effect of small amount of cation dopant on phase stability of zirconia bioceramics is evaluated by ageing in hot water. The phase transformation progresses with time in all specimens. However, the tetragonal to monoclinic transformation behavior is much different depending on the dopant. In case that the small amount of tetravalent soluble 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, which is explained from the change in the axial ratio, c/a. However, the change in phase stability of 7.7mol%TiO2-doped TZP cannot be simply explained from the change in the axial ratio, c/a. XRD analysis reveals that the distance between nearest neighbor anion and cation site significantly decreases only in 7.7mol%TiO2-doped TZP. This result indicates that the binding energy between dopant and oxygen vacancy affects the phase stability as well as the change in the axial ratio, c/a.

Effect of Dopant on Phase Stability of Zirconia in Hot Water

2006 ◽  
Vol 309-311 ◽  
pp. 1231-1234 ◽  
Author(s):  
Yukihisa Naka ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Phase Transformation ◽  
Phase Stability ◽  
Ionic Radius ◽  
Hot Water ◽  
Transformation Behavior ◽  
M Phase

The effect of cation dopant on tetragonal to monoclinic (t-m) phase transformation of zirconia is examined, which causes the degradation of zirconia in vivo. The transformation behavior is much different depending of the dopant. The transformation is promoted when the pentavalent element is added. In contrast, the transformation is suppressed when the bivalent element is added. In case the tetravalent element is added, the transformation is promoted if the ionic radius of the element is larger than that of zirconium, and that is suppressed if the element with smaller ionic radius is added. The valence and the ionic radius of dopant must be important factors for the phase stability of zirconia.

scholarly journals Influence of Preaging Temperature on the Indentation Strength of 3Y-TZP Aged in Ambient Atmosphere

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2767
Author(s):  
Ki-Won Jeong ◽  
Jung-Suk Han ◽  
Gi-Uk Yang ◽  
Dae-Joon Kim
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Low Temperature ◽  
Compressive Residual Stress ◽  
Yttria Stabilized Zirconia ◽  
Ambient Atmosphere ◽  
Aged Specimen ◽  
Stabilized Zirconia ◽  
M Phase ◽  
The Relationship

Yttria-stabilized zirconia (3Y-TZP) containing 0.25% Al2O3, which is resistant to low temperature degradation (LTD), was aged for 10 h at 130–220 °C in air. The aged specimens were subsequently indented at loads ranging from 9.8 to 490 N using a Vickers indenter. The influence of preaging temperature on the biaxial strength of the specimens was investigated to elucidate the relationship between the extent of LTD and the strength of zirconia restorations that underwent LTD. The indented strength of the specimens increased as the preaging temperature was increased higher than 160 °C, which was accompanied by extensive t-ZrO2 (t) to m-ZrO2 (m) and c-ZrO2 (c) to r-ZrO2 (r) phase transformations. The influence of preaging temperature on the indented strength was rationalized by the residual stresses raised by the t→m transformation and the reversal of tensile residual stress on the aged specimen surface due to the indentation. The results suggested that the longevity of restorations would not be deteriorated if the aged restorations retain compressive residual stress on the surface, which corresponds to the extent of t→m phase transformation less than 52% in ambient environment.

Environmental Effect on the Crack Behavior of Yttria-Stabilized Zirconia During Laser Drilling

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Hong Shen ◽  
Juan Jiang ◽  
Decai Feng ◽  
Chen Xing ◽  
Xiaofeng Zhao ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Phase Transformation ◽  
Environmental Effect ◽  
Monoclinic Phase ◽  
Oxygen Vacancies ◽  
High Stress ◽  
Laser Drilling ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Crack Behavior

The crack behaviors of yttrium-stabilized zirconia during laser drilling in air, vacuum, and water environments were investigated. Due to the high stress and low fracture toughness induced by tetragonal-monoclinic phase transformation, tremendous cracks occur during drilling in air. Contrastly, cracks were reduced in vacuum drilling since the phase transformation was suppressed due to the generation of oxygen vacancies. By protection of water, no cracks were observed due to low stress and maintained fracture toughness. The crack mechanisms in different drilling media were discussed.

Investigation on the phase stability of yttria-stabilized zirconia electrolytes for high-temperature electrochemical application

2019 ◽  
Vol 45 (7) ◽  
pp. 9462-9467 ◽  
Author(s):  
Kuk-Jin Hwang ◽  
Miyoung Shin ◽  
Myung-Hyun Lee ◽  
Heesoo Lee ◽  
Mi Young Oh ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Stability ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Electrochemical Application

Multiscale Surface Patterning of Zirconia by Picosecond Pulsed Laser Irradiation

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuka Yamamuro ◽  
Tomotaka Shimoyama ◽  
Isao Yamashita ◽  
Jiwang Yan
Keyword(s):  
Phase Transformation ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Surface Patterning ◽  
Yttria Stabilized Zirconia ◽  
Surface Structures ◽  
Stabilized Zirconia ◽  
Periodic Surface ◽  
Thermally Induced ◽  
Pulsed Laser Irradiation

Abstract Irradiation of yttria-stabilized zirconia (YSZ) was performed by a picosecond pulsed laser to investigate the possibility for multiscale surface patterning. Nanoscale laser-induced periodic surface structures (LIPSS) were successfully generated inside microscale grooves over a large surface area under specific conditions. A thermally induced phase transformation of YSZ was identified after laser irradiation, and this phase transformation was restrained by reducing the laser power or the number of irradiations. Moreover, it was found that the generation of LIPSS greatly changed the surface wettability of YSZ. These results demonstrated the possibility of creating zirconia hybrid patterns with high functionality, which may expand the applications of YSZ in industry.

scholarly journals Evaluation of Phase Transformation and Mechanical Properties of Metastable Yttria-Stabilized Zirconia by Nanoindentation

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1677 ◽  
Author(s):  
Ningning Song ◽  
Ziyuan Wang ◽  
Yan Xing ◽  
Mengfei Zhang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Young’S Modulus ◽  
Tetragonal Phase ◽  
Young's Modulus ◽  
Traditional Approach ◽  
Yttria Stabilized Zirconia ◽  
Phase Identification ◽  
Stabilized Zirconia ◽  
T Phase

Microscopical nonuniformity of mechanical properties caused by phase transformation is one of the main reasons for the failure of the materials in engineering applications. Accurate measurement of the mechanical properties of each phase is of virtual importance, in which the traditional approach like Vickers hardness cannot accomplish, due to the large testing range. In this study, nanoindentation is firstly used to analyze the mechanical properties of each phase and demonstrate the phase transformation in thermal barrier coatings during high-temperature aging. The distribution of T-prime metastable tetragonal phase, cubic and tetragonal phase is determined by mapping mode of nanoindentation and confirmed with X-ray diffraction and scanning electron microscope observation. The results show that during 1300 °C aging, the phase transition of metastable Yttria-Stabilized Zirconia induces the quick decrease of T′ phase content and an increase of T and C phases accordingly. It is found that there are some fluctuations in the mechanical properties of individual phase during annealing. The hardness and Young’s modulus of T′ increase at first 9 h, due to the precipitation of Y3+ lean T phase and then decrease to a constant value accompanied by the precipitation of Y3+ rich C phase. The relevant property of C phases also increases a little firstly and then decreases to a constant, due to the homogenization of Y3+ content, while the hardness and Young’s modulus of T phase remain unchanged. After aging of 24h the hardness of T′, C and T phases are 20.5 GPa, 21.3 GPa and 19.1 GPa, respectively. The Young’s modulus of T′, C and T phases are 274 GPa, 275 GPa and 265 GPa, respectively. Present work reveals the availability of nanoindentation method to demonstrate the phase transformation and measure mechanical properties of composites. It also provides an efficient application for single phase identification of ceramics.

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